User login
Trial updates will help tailor endocrine therapy for premenopausal breast cancer
SAN ANTONIO – Adjuvant endocrine therapies improve outcomes of premenopausal breast cancer in the long term, with absolute benefit varying somewhat by therapy and by patient and disease characteristics, according to planned updates of a pair of pivotal phase 3 trials.
The trials – TEXT (Tamoxifen and Exemestane Trial) and SOFT (Suppression of Ovarian Function Trial) – are coordinated by the International Breast Cancer Study Group and together randomized more than 5,000 premenopausal women with early hormone receptor–positive breast cancer to 5 years of various types of adjuvant endocrine therapy. Their initial results, reported several years ago, form part of treatment guidelines that are used worldwide.
In an updated joint analysis of TEXT and SOFT, benefit of the aromatase inhibitor (AI) exemestane plus ovarian function suppression (OFS) over the selective estrogen-receptor modulator tamoxifen plus OFS was sustained, with a 4.0% absolute gain in 8-year disease-free survival, investigators reported at the San Antonio Breast Cancer Symposium. And in an updated analysis of SOFT, the benefit of tamoxifen plus OFS over tamoxifen alone became significant, with a 4.2% absolute gain in 8-year disease-free survival.
Relative benefits for various outcomes were generally similar across subgroups, but absolute benefits were greater for women having certain features increasing risk for poor outcomes.
Clinical implications
These updates, along with other emerging data, can be used to optimize endocrine therapy for younger women with breast cancer, according to invited discussant Ann H. Partridge, MD, of Dana Farber Cancer Institute in Boston.
“For higher-risk disease, we should be considering OFS. At this point in time, I don’t think HER2 status alone should drive this decision,” she commented. “If you are getting OFS, what do we do, AI versus tamoxifen? Well, we do see a large improvement in disease-free survival [with AIs], so many women will want to use AIs. Yet tamoxifen is still reasonable, especially in light of the survival data.”
Data on switch strategies and extended-duration therapy are generally lacking at present for the premenopausal population, Dr. Partridge noted. “That’s something that we still need to extrapolate from data that’s predominantly in postmenopausal women.”
Another compelling question is whether OFS can be used instead of chemo for some patients. “We are increasingly recognizing that women with higher-risk anatomy and lower-risk biology having endocrine-responsive tumors may get more bang for the buck from the optimizing of hormonal therapy, and chemo may not add much,” she said.
Both short- and long-term toxicities of the various endocrine therapies and, for aromatase inhibitors, the potential for breakthrough (return of estradiol levels to premenopausal levels) also need to be considered, Dr. Partridge stressed. “And ultimately, patient preference and tolerance are key. After all, the best treatment is the one the patient will take.”
“We need to follow these women on TEXT and SOFT very long term. It would be a crime not to follow these women further out,” she maintained. “We need to conduct real-world comparative effectiveness research to understand the risks and benefits of OFS more fully in our survivors. Then, as we start to suppress more ovaries in more women with breast cancer, we need to be aware clinically of these risks, and we need to share this awareness with their primary care providers because we need to optimize in particular their cardiovascular risk factors, and screen and treat for potential comorbidities that they may be at higher risk for.”
Joint TEXT and SOFT update
Initial results of the joint TEXT and SOFT analysis, reported after a median follow-up of 5.7 years, showed that exemestane plus OFS was superior to tamoxifen plus OFS for the primary outcome, providing a significant 3.8% absolute gain in 5-year disease-free survival (N Engl J Med. 2014;371:107-18).
The updated joint analysis, now with a median follow-up of 9 years and based on data from 4,690 women, showed that the 8-year rate of disease-free survival was 86.8% with exemestane plus OFS versus 82.8% with tamoxifen plus OFS (hazard ratio, 0.77; P = .0006), for a similar absolute benefit of 4.0%, reported Prudence Francis, MD, of the University of Melbourne, head of Medical Oncology in the Breast Service at the Peter MacCallum Cancer Centre, Melbourne.
In stratified analysis, absolute benefit tended to be greater among women in TEXT who received chemotherapy (6.0%); intermediate among women in TEXT who did not receive chemotherapy (3.7%) and women in SOFT who received prior chemotherapy (3.7%); and less among women in SOFT who did not receive chemotherapy (1.9%).
Exemestane plus OFS was also superior to tamoxifen plus OFS in terms of breast cancer–free interval, with an absolute 4.1% benefit (P = .0002), and distant recurrence–free interval, with an absolute 2.1% benefit (P = .02). Overall survival did not differ significantly between arms.
Among the 86% of patients with HER2-negative disease, exemestane plus OFS netted an absolute disease-free survival gain of 5.4% and an absolute distant recurrence–free interval gain of 3.4%. There was a consistent relative treatment benefit across subgroups, but larger absolute benefit, on the order of 5%-9%, in women given chemotherapy and in those younger than 35 years.
“Results for the HER2-positive subgroup require further investigation,” Dr. Francis said. “The trials enrolled both before and after the routine use of adjuvant trastuzumab, and a significant proportion of the patients with HER2-positive breast cancer did not receive adjuvant HER2-targeted therapy.”
In the entire joint-analysis population, exemestane plus OFS was associated with higher rates of musculoskeletal events of grade 3 or 4 (11% vs. 6%) and osteoporosis of grade 2-4 (15% vs. 7%), while tamoxifen plus OFS was associated with a higher rate of thrombosis/embolism of grade 2-4 (2.3% vs. 1.2%) and more cases of endometrial cancer (9 vs. 4 cases). At 4 years, early discontinuation of oral endocrine therapy was greater for exemestane than for tamoxifen (25% vs. 19%).
“After longer follow-up, with a median of 9 years, the combined analysis results confirm a statistically significant improvement in disease outcomes with exemestane plus ovarian suppression. As is critical given the long natural history of estrogen receptor–positive breast cancer, follow-up in these trials is currently continuing,” Dr. Francis summarized.
“To optimally translate the observed absolute trial improvements into clinical practice, oncologists need to discuss and weigh the potential benefits and toxicities in each individual patient who is premenopausal with hormone receptor–positive breast cancer,” she recommended.
Session attendee Hope S. Rugo, MD, of the University of California, San Francisco, Helen Diller Family Comprehensive Cancer Center, noted that exemestane had superior benefit despite the 25% rate of early discontinuation. “I wonder if one of the interpretations of that, given the toxicity of this therapy for very young women, is that we need some but maybe not so much. Maybe they don’t need 5 years altogether,” she said.
“The fact that they stopped their assigned endocrine therapy doesn’t mean that they didn’t continue any therapy. They may have switched over to tamoxifen or they may have decided they wanted to have a baby or there may have been many other things,” Dr. Francis replied, noting that analyses sorting out the reasons for early discontinuation are planned.
Session attendee Mark E. Sherman, MD, of the Mayo Clinic, Jacksonville, Fla., asked, “Do you have any ability to test for tamoxifen metabolites? It’s possible that a third to a half of patients got reduced benefit from that drug.”
Banked samples are available and a substudy is planned, according to Dr. Francis. “We haven’t got data on that yet, but yes, we are analyzing that.”
SOFT update
Initial results of the SOFT trial, reported after a median follow-up of 5.6 years, showed that adding OFS to tamoxifen did not significantly improve disease-free survival over tamoxifen alone in the entire trial population (N Engl J Med. 2015;372:436-46). However, there was benefit for women who received chemotherapy and remained premenopausal.
The updated SOFT analysis, now with a median follow-up of 8 years, focused mainly on the 1,018 women given tamoxifen alone and the 1,015 women given tamoxifen plus OFS. (Another 1,014 women were given exemestane plus OFS.)
“SOFT is now positive for its primary endpoint,” reported first author Gini Fleming, MD, director of the Medical Oncology Breast Program and medical oncology director of Gynecologic Oncology at University of Chicago Medicine. The 8-year disease-free survival rate was 83.2% with tamoxifen plus OFS, compared with 78.9% with tamoxifen alone (HR, 0.76; P = .009), corresponding to a 4.2% gain in this outcome. The relative benefit was identical whether patients had received chemotherapy or not, but absolute benefit was greater for those who had (5.3%), as well as for patients younger than 35 years (8.7%).
In addition, exemestane plus OFS was superior to tamoxifen alone (85.9% vs. 78.9%; HR, 0.65), with an absolute benefit of 7.0%. Again, absolute benefit was more pronounced among women who had received prior chemotherapy (9.0%) or were younger than 35 years (13.1%).
The relative disease-free survival benefit of tamoxifen plus OFS over tamoxifen alone was similar across most subgroups stratified by disease characteristics, but patients with HER2-positive disease derived greater relative benefit from the combination as compared with their HER2-negative counterparts (P = .04 for interaction). “When we look at the combination of exemestane plus OFS versus tamoxifen, this heterogeneity is no longer seen,” Dr. Fleming noted.
In the entire trial population, there was no significant benefit of tamoxifen plus OFS over tamoxifen alone for distant recurrence-free interval and a small, significant absolute 1.9% gain in overall survival.
“The cohort who had elected to receive no prior chemotherapy did exceedingly well regardless of therapy,” she said, with little difference in overall survival across the three arms. “There were only 24 deaths total in this cohort, and 12 of those deaths were in the setting of no distant recurrence.”
On the other hand, among the women who received chemotherapy, there were significant absolute overall survival benefits of 4.3% with tamoxifen plus OFS and 2.1% with exemestane plus OFS, over tamoxifen alone. “This late emergence of an overall survival benefit is consistent with the time course of events in estrogen receptor–positive breast cancer,” Dr. Fleming commented.
The proportion of patients who stopped their oral endocrine therapy early was 22.5% with tamoxifen alone and 18.5% with tamoxifen plus OFS. (It was 27.8% with exemestane plus OFS.) “Almost a quarter of the patients on either tamoxifen arm were using extended oral endocrine therapy at 6 years or later prior to any disease progression. Only about 12% of patients in the exemestane group were doing so,” she noted.
There were more cases of endometrial cancer with tamoxifen alone than with tamoxifen plus OFS (7 vs. 4 cases). Thrombosis/embolism of grade 2-4 occurred in 2.2% of each group (and 0.9% of the exemestane plus OFS group). Musculoskeletal symptoms of grade 3 or 4 occurred in 6.7% of patients with tamoxifen alone and 5.9% with tamoxifen plus OFS, but 12.0% with exemestane plus OFS. Respective rates of osteoporosis grade 2-4 were 3.9%, 6.1%, and 11.9%.
“The addition of OFS to tamoxifen significantly improves disease-free survival at 8 years’ median follow-up, and disease-free survival benefits are further improved by the use of exemestane plus OFS,” Dr. Fleming summarized. “Follow-up, which is critically important given the long natural history of ER-positive disease, continues.”
Session attendee Matthew P. Goetz, MD, of the Mayo Clinic, Rochester, Minn., commented, “For the primary endpoint, I was looking at the tail for tamoxifen. It seemed that there was a relatively rapid drop-off between year 5 and this 8-year follow-up. Have you looked carefully to see whether there is a difference between those who stayed on their therapy versus those who went off it per protocol? That is, extended versus not extended? The question is whether there is a carry-over effect, if you will, that is different in those with OFS versus those not.”
“The percent who went on to extended therapy between the tamoxifen and the tamoxifen plus OFS was fairly similar,” Dr. Fleming replied. “But the answer is no, we have not yet done any sort of per protocol analysis.”
Session attendee Steven Vogl, MD, of Montefiore Medical Center, New York, commented, “I worry about your control group. I’m worried, first, how many of your tamoxifen patients lost their menses and became postmenopausal in those 5 years? And of those, why didn’t they switch to an aromatase inhibitor? Only 25% of the patients continued after the 5 years according to your slide, and all of those patients should either have stayed on tamoxifen or switched to an aromatase inhibitor, now probably for 2 years at least.”
“We have not yet looked at data for who became amenorrheic during treatment, although we have it. However, it’s certainly possible to become amenorrheic on tamoxifen and not be postmenopausal, and we didn’t regularly collect estradiol levels on any but the very small subset of women in the SOFT-S trial. So I don’t know that we have exactly the data that you’re looking for,” Dr. Fleming said. “Many of these women are obviously at very, very low risk and have done well with 5 years of tamoxifen alone, and I don’t know, even given current guidelines, that extended tamoxifen would add a lot to that.”
Finally, session attendee Richard Gray, professor of medical statistics at the University of Oxford (England), wondered, “What is the certainty that follow-up will happen? Because obviously, prolonged follow-up is expensive and there are controversies about that. But this would be the one study you would really want to have 15- and 20-year data on.”
“We are working very, very hard on that,” Dr. Fleming replied. “NCI granted additional funds to institutions for prolonging follow-up, and IBCSG has been ceaselessly working to look for funding to continue it. So I think it’s relatively certain that it will happen.”
Dr. Francis disclosed that she has received fees for non-CME services from AstraZeneca and has given an overseas lecture for Pfizer. Dr. Fleming disclosed that she had no relevant financial relationships with commercial interests. The trials received financial support from Pfizer and Ipsen.
SOURCES: Francis et al. SABCS Abstract GS4-02; Fleming et al. SABCS Abstract GS4-03
SAN ANTONIO – Adjuvant endocrine therapies improve outcomes of premenopausal breast cancer in the long term, with absolute benefit varying somewhat by therapy and by patient and disease characteristics, according to planned updates of a pair of pivotal phase 3 trials.
The trials – TEXT (Tamoxifen and Exemestane Trial) and SOFT (Suppression of Ovarian Function Trial) – are coordinated by the International Breast Cancer Study Group and together randomized more than 5,000 premenopausal women with early hormone receptor–positive breast cancer to 5 years of various types of adjuvant endocrine therapy. Their initial results, reported several years ago, form part of treatment guidelines that are used worldwide.
In an updated joint analysis of TEXT and SOFT, benefit of the aromatase inhibitor (AI) exemestane plus ovarian function suppression (OFS) over the selective estrogen-receptor modulator tamoxifen plus OFS was sustained, with a 4.0% absolute gain in 8-year disease-free survival, investigators reported at the San Antonio Breast Cancer Symposium. And in an updated analysis of SOFT, the benefit of tamoxifen plus OFS over tamoxifen alone became significant, with a 4.2% absolute gain in 8-year disease-free survival.
Relative benefits for various outcomes were generally similar across subgroups, but absolute benefits were greater for women having certain features increasing risk for poor outcomes.
Clinical implications
These updates, along with other emerging data, can be used to optimize endocrine therapy for younger women with breast cancer, according to invited discussant Ann H. Partridge, MD, of Dana Farber Cancer Institute in Boston.
“For higher-risk disease, we should be considering OFS. At this point in time, I don’t think HER2 status alone should drive this decision,” she commented. “If you are getting OFS, what do we do, AI versus tamoxifen? Well, we do see a large improvement in disease-free survival [with AIs], so many women will want to use AIs. Yet tamoxifen is still reasonable, especially in light of the survival data.”
Data on switch strategies and extended-duration therapy are generally lacking at present for the premenopausal population, Dr. Partridge noted. “That’s something that we still need to extrapolate from data that’s predominantly in postmenopausal women.”
Another compelling question is whether OFS can be used instead of chemo for some patients. “We are increasingly recognizing that women with higher-risk anatomy and lower-risk biology having endocrine-responsive tumors may get more bang for the buck from the optimizing of hormonal therapy, and chemo may not add much,” she said.
Both short- and long-term toxicities of the various endocrine therapies and, for aromatase inhibitors, the potential for breakthrough (return of estradiol levels to premenopausal levels) also need to be considered, Dr. Partridge stressed. “And ultimately, patient preference and tolerance are key. After all, the best treatment is the one the patient will take.”
“We need to follow these women on TEXT and SOFT very long term. It would be a crime not to follow these women further out,” she maintained. “We need to conduct real-world comparative effectiveness research to understand the risks and benefits of OFS more fully in our survivors. Then, as we start to suppress more ovaries in more women with breast cancer, we need to be aware clinically of these risks, and we need to share this awareness with their primary care providers because we need to optimize in particular their cardiovascular risk factors, and screen and treat for potential comorbidities that they may be at higher risk for.”
Joint TEXT and SOFT update
Initial results of the joint TEXT and SOFT analysis, reported after a median follow-up of 5.7 years, showed that exemestane plus OFS was superior to tamoxifen plus OFS for the primary outcome, providing a significant 3.8% absolute gain in 5-year disease-free survival (N Engl J Med. 2014;371:107-18).
The updated joint analysis, now with a median follow-up of 9 years and based on data from 4,690 women, showed that the 8-year rate of disease-free survival was 86.8% with exemestane plus OFS versus 82.8% with tamoxifen plus OFS (hazard ratio, 0.77; P = .0006), for a similar absolute benefit of 4.0%, reported Prudence Francis, MD, of the University of Melbourne, head of Medical Oncology in the Breast Service at the Peter MacCallum Cancer Centre, Melbourne.
In stratified analysis, absolute benefit tended to be greater among women in TEXT who received chemotherapy (6.0%); intermediate among women in TEXT who did not receive chemotherapy (3.7%) and women in SOFT who received prior chemotherapy (3.7%); and less among women in SOFT who did not receive chemotherapy (1.9%).
Exemestane plus OFS was also superior to tamoxifen plus OFS in terms of breast cancer–free interval, with an absolute 4.1% benefit (P = .0002), and distant recurrence–free interval, with an absolute 2.1% benefit (P = .02). Overall survival did not differ significantly between arms.
Among the 86% of patients with HER2-negative disease, exemestane plus OFS netted an absolute disease-free survival gain of 5.4% and an absolute distant recurrence–free interval gain of 3.4%. There was a consistent relative treatment benefit across subgroups, but larger absolute benefit, on the order of 5%-9%, in women given chemotherapy and in those younger than 35 years.
“Results for the HER2-positive subgroup require further investigation,” Dr. Francis said. “The trials enrolled both before and after the routine use of adjuvant trastuzumab, and a significant proportion of the patients with HER2-positive breast cancer did not receive adjuvant HER2-targeted therapy.”
In the entire joint-analysis population, exemestane plus OFS was associated with higher rates of musculoskeletal events of grade 3 or 4 (11% vs. 6%) and osteoporosis of grade 2-4 (15% vs. 7%), while tamoxifen plus OFS was associated with a higher rate of thrombosis/embolism of grade 2-4 (2.3% vs. 1.2%) and more cases of endometrial cancer (9 vs. 4 cases). At 4 years, early discontinuation of oral endocrine therapy was greater for exemestane than for tamoxifen (25% vs. 19%).
“After longer follow-up, with a median of 9 years, the combined analysis results confirm a statistically significant improvement in disease outcomes with exemestane plus ovarian suppression. As is critical given the long natural history of estrogen receptor–positive breast cancer, follow-up in these trials is currently continuing,” Dr. Francis summarized.
“To optimally translate the observed absolute trial improvements into clinical practice, oncologists need to discuss and weigh the potential benefits and toxicities in each individual patient who is premenopausal with hormone receptor–positive breast cancer,” she recommended.
Session attendee Hope S. Rugo, MD, of the University of California, San Francisco, Helen Diller Family Comprehensive Cancer Center, noted that exemestane had superior benefit despite the 25% rate of early discontinuation. “I wonder if one of the interpretations of that, given the toxicity of this therapy for very young women, is that we need some but maybe not so much. Maybe they don’t need 5 years altogether,” she said.
“The fact that they stopped their assigned endocrine therapy doesn’t mean that they didn’t continue any therapy. They may have switched over to tamoxifen or they may have decided they wanted to have a baby or there may have been many other things,” Dr. Francis replied, noting that analyses sorting out the reasons for early discontinuation are planned.
Session attendee Mark E. Sherman, MD, of the Mayo Clinic, Jacksonville, Fla., asked, “Do you have any ability to test for tamoxifen metabolites? It’s possible that a third to a half of patients got reduced benefit from that drug.”
Banked samples are available and a substudy is planned, according to Dr. Francis. “We haven’t got data on that yet, but yes, we are analyzing that.”
SOFT update
Initial results of the SOFT trial, reported after a median follow-up of 5.6 years, showed that adding OFS to tamoxifen did not significantly improve disease-free survival over tamoxifen alone in the entire trial population (N Engl J Med. 2015;372:436-46). However, there was benefit for women who received chemotherapy and remained premenopausal.
The updated SOFT analysis, now with a median follow-up of 8 years, focused mainly on the 1,018 women given tamoxifen alone and the 1,015 women given tamoxifen plus OFS. (Another 1,014 women were given exemestane plus OFS.)
“SOFT is now positive for its primary endpoint,” reported first author Gini Fleming, MD, director of the Medical Oncology Breast Program and medical oncology director of Gynecologic Oncology at University of Chicago Medicine. The 8-year disease-free survival rate was 83.2% with tamoxifen plus OFS, compared with 78.9% with tamoxifen alone (HR, 0.76; P = .009), corresponding to a 4.2% gain in this outcome. The relative benefit was identical whether patients had received chemotherapy or not, but absolute benefit was greater for those who had (5.3%), as well as for patients younger than 35 years (8.7%).
In addition, exemestane plus OFS was superior to tamoxifen alone (85.9% vs. 78.9%; HR, 0.65), with an absolute benefit of 7.0%. Again, absolute benefit was more pronounced among women who had received prior chemotherapy (9.0%) or were younger than 35 years (13.1%).
The relative disease-free survival benefit of tamoxifen plus OFS over tamoxifen alone was similar across most subgroups stratified by disease characteristics, but patients with HER2-positive disease derived greater relative benefit from the combination as compared with their HER2-negative counterparts (P = .04 for interaction). “When we look at the combination of exemestane plus OFS versus tamoxifen, this heterogeneity is no longer seen,” Dr. Fleming noted.
In the entire trial population, there was no significant benefit of tamoxifen plus OFS over tamoxifen alone for distant recurrence-free interval and a small, significant absolute 1.9% gain in overall survival.
“The cohort who had elected to receive no prior chemotherapy did exceedingly well regardless of therapy,” she said, with little difference in overall survival across the three arms. “There were only 24 deaths total in this cohort, and 12 of those deaths were in the setting of no distant recurrence.”
On the other hand, among the women who received chemotherapy, there were significant absolute overall survival benefits of 4.3% with tamoxifen plus OFS and 2.1% with exemestane plus OFS, over tamoxifen alone. “This late emergence of an overall survival benefit is consistent with the time course of events in estrogen receptor–positive breast cancer,” Dr. Fleming commented.
The proportion of patients who stopped their oral endocrine therapy early was 22.5% with tamoxifen alone and 18.5% with tamoxifen plus OFS. (It was 27.8% with exemestane plus OFS.) “Almost a quarter of the patients on either tamoxifen arm were using extended oral endocrine therapy at 6 years or later prior to any disease progression. Only about 12% of patients in the exemestane group were doing so,” she noted.
There were more cases of endometrial cancer with tamoxifen alone than with tamoxifen plus OFS (7 vs. 4 cases). Thrombosis/embolism of grade 2-4 occurred in 2.2% of each group (and 0.9% of the exemestane plus OFS group). Musculoskeletal symptoms of grade 3 or 4 occurred in 6.7% of patients with tamoxifen alone and 5.9% with tamoxifen plus OFS, but 12.0% with exemestane plus OFS. Respective rates of osteoporosis grade 2-4 were 3.9%, 6.1%, and 11.9%.
“The addition of OFS to tamoxifen significantly improves disease-free survival at 8 years’ median follow-up, and disease-free survival benefits are further improved by the use of exemestane plus OFS,” Dr. Fleming summarized. “Follow-up, which is critically important given the long natural history of ER-positive disease, continues.”
Session attendee Matthew P. Goetz, MD, of the Mayo Clinic, Rochester, Minn., commented, “For the primary endpoint, I was looking at the tail for tamoxifen. It seemed that there was a relatively rapid drop-off between year 5 and this 8-year follow-up. Have you looked carefully to see whether there is a difference between those who stayed on their therapy versus those who went off it per protocol? That is, extended versus not extended? The question is whether there is a carry-over effect, if you will, that is different in those with OFS versus those not.”
“The percent who went on to extended therapy between the tamoxifen and the tamoxifen plus OFS was fairly similar,” Dr. Fleming replied. “But the answer is no, we have not yet done any sort of per protocol analysis.”
Session attendee Steven Vogl, MD, of Montefiore Medical Center, New York, commented, “I worry about your control group. I’m worried, first, how many of your tamoxifen patients lost their menses and became postmenopausal in those 5 years? And of those, why didn’t they switch to an aromatase inhibitor? Only 25% of the patients continued after the 5 years according to your slide, and all of those patients should either have stayed on tamoxifen or switched to an aromatase inhibitor, now probably for 2 years at least.”
“We have not yet looked at data for who became amenorrheic during treatment, although we have it. However, it’s certainly possible to become amenorrheic on tamoxifen and not be postmenopausal, and we didn’t regularly collect estradiol levels on any but the very small subset of women in the SOFT-S trial. So I don’t know that we have exactly the data that you’re looking for,” Dr. Fleming said. “Many of these women are obviously at very, very low risk and have done well with 5 years of tamoxifen alone, and I don’t know, even given current guidelines, that extended tamoxifen would add a lot to that.”
Finally, session attendee Richard Gray, professor of medical statistics at the University of Oxford (England), wondered, “What is the certainty that follow-up will happen? Because obviously, prolonged follow-up is expensive and there are controversies about that. But this would be the one study you would really want to have 15- and 20-year data on.”
“We are working very, very hard on that,” Dr. Fleming replied. “NCI granted additional funds to institutions for prolonging follow-up, and IBCSG has been ceaselessly working to look for funding to continue it. So I think it’s relatively certain that it will happen.”
Dr. Francis disclosed that she has received fees for non-CME services from AstraZeneca and has given an overseas lecture for Pfizer. Dr. Fleming disclosed that she had no relevant financial relationships with commercial interests. The trials received financial support from Pfizer and Ipsen.
SOURCES: Francis et al. SABCS Abstract GS4-02; Fleming et al. SABCS Abstract GS4-03
SAN ANTONIO – Adjuvant endocrine therapies improve outcomes of premenopausal breast cancer in the long term, with absolute benefit varying somewhat by therapy and by patient and disease characteristics, according to planned updates of a pair of pivotal phase 3 trials.
The trials – TEXT (Tamoxifen and Exemestane Trial) and SOFT (Suppression of Ovarian Function Trial) – are coordinated by the International Breast Cancer Study Group and together randomized more than 5,000 premenopausal women with early hormone receptor–positive breast cancer to 5 years of various types of adjuvant endocrine therapy. Their initial results, reported several years ago, form part of treatment guidelines that are used worldwide.
In an updated joint analysis of TEXT and SOFT, benefit of the aromatase inhibitor (AI) exemestane plus ovarian function suppression (OFS) over the selective estrogen-receptor modulator tamoxifen plus OFS was sustained, with a 4.0% absolute gain in 8-year disease-free survival, investigators reported at the San Antonio Breast Cancer Symposium. And in an updated analysis of SOFT, the benefit of tamoxifen plus OFS over tamoxifen alone became significant, with a 4.2% absolute gain in 8-year disease-free survival.
Relative benefits for various outcomes were generally similar across subgroups, but absolute benefits were greater for women having certain features increasing risk for poor outcomes.
Clinical implications
These updates, along with other emerging data, can be used to optimize endocrine therapy for younger women with breast cancer, according to invited discussant Ann H. Partridge, MD, of Dana Farber Cancer Institute in Boston.
“For higher-risk disease, we should be considering OFS. At this point in time, I don’t think HER2 status alone should drive this decision,” she commented. “If you are getting OFS, what do we do, AI versus tamoxifen? Well, we do see a large improvement in disease-free survival [with AIs], so many women will want to use AIs. Yet tamoxifen is still reasonable, especially in light of the survival data.”
Data on switch strategies and extended-duration therapy are generally lacking at present for the premenopausal population, Dr. Partridge noted. “That’s something that we still need to extrapolate from data that’s predominantly in postmenopausal women.”
Another compelling question is whether OFS can be used instead of chemo for some patients. “We are increasingly recognizing that women with higher-risk anatomy and lower-risk biology having endocrine-responsive tumors may get more bang for the buck from the optimizing of hormonal therapy, and chemo may not add much,” she said.
Both short- and long-term toxicities of the various endocrine therapies and, for aromatase inhibitors, the potential for breakthrough (return of estradiol levels to premenopausal levels) also need to be considered, Dr. Partridge stressed. “And ultimately, patient preference and tolerance are key. After all, the best treatment is the one the patient will take.”
“We need to follow these women on TEXT and SOFT very long term. It would be a crime not to follow these women further out,” she maintained. “We need to conduct real-world comparative effectiveness research to understand the risks and benefits of OFS more fully in our survivors. Then, as we start to suppress more ovaries in more women with breast cancer, we need to be aware clinically of these risks, and we need to share this awareness with their primary care providers because we need to optimize in particular their cardiovascular risk factors, and screen and treat for potential comorbidities that they may be at higher risk for.”
Joint TEXT and SOFT update
Initial results of the joint TEXT and SOFT analysis, reported after a median follow-up of 5.7 years, showed that exemestane plus OFS was superior to tamoxifen plus OFS for the primary outcome, providing a significant 3.8% absolute gain in 5-year disease-free survival (N Engl J Med. 2014;371:107-18).
The updated joint analysis, now with a median follow-up of 9 years and based on data from 4,690 women, showed that the 8-year rate of disease-free survival was 86.8% with exemestane plus OFS versus 82.8% with tamoxifen plus OFS (hazard ratio, 0.77; P = .0006), for a similar absolute benefit of 4.0%, reported Prudence Francis, MD, of the University of Melbourne, head of Medical Oncology in the Breast Service at the Peter MacCallum Cancer Centre, Melbourne.
In stratified analysis, absolute benefit tended to be greater among women in TEXT who received chemotherapy (6.0%); intermediate among women in TEXT who did not receive chemotherapy (3.7%) and women in SOFT who received prior chemotherapy (3.7%); and less among women in SOFT who did not receive chemotherapy (1.9%).
Exemestane plus OFS was also superior to tamoxifen plus OFS in terms of breast cancer–free interval, with an absolute 4.1% benefit (P = .0002), and distant recurrence–free interval, with an absolute 2.1% benefit (P = .02). Overall survival did not differ significantly between arms.
Among the 86% of patients with HER2-negative disease, exemestane plus OFS netted an absolute disease-free survival gain of 5.4% and an absolute distant recurrence–free interval gain of 3.4%. There was a consistent relative treatment benefit across subgroups, but larger absolute benefit, on the order of 5%-9%, in women given chemotherapy and in those younger than 35 years.
“Results for the HER2-positive subgroup require further investigation,” Dr. Francis said. “The trials enrolled both before and after the routine use of adjuvant trastuzumab, and a significant proportion of the patients with HER2-positive breast cancer did not receive adjuvant HER2-targeted therapy.”
In the entire joint-analysis population, exemestane plus OFS was associated with higher rates of musculoskeletal events of grade 3 or 4 (11% vs. 6%) and osteoporosis of grade 2-4 (15% vs. 7%), while tamoxifen plus OFS was associated with a higher rate of thrombosis/embolism of grade 2-4 (2.3% vs. 1.2%) and more cases of endometrial cancer (9 vs. 4 cases). At 4 years, early discontinuation of oral endocrine therapy was greater for exemestane than for tamoxifen (25% vs. 19%).
“After longer follow-up, with a median of 9 years, the combined analysis results confirm a statistically significant improvement in disease outcomes with exemestane plus ovarian suppression. As is critical given the long natural history of estrogen receptor–positive breast cancer, follow-up in these trials is currently continuing,” Dr. Francis summarized.
“To optimally translate the observed absolute trial improvements into clinical practice, oncologists need to discuss and weigh the potential benefits and toxicities in each individual patient who is premenopausal with hormone receptor–positive breast cancer,” she recommended.
Session attendee Hope S. Rugo, MD, of the University of California, San Francisco, Helen Diller Family Comprehensive Cancer Center, noted that exemestane had superior benefit despite the 25% rate of early discontinuation. “I wonder if one of the interpretations of that, given the toxicity of this therapy for very young women, is that we need some but maybe not so much. Maybe they don’t need 5 years altogether,” she said.
“The fact that they stopped their assigned endocrine therapy doesn’t mean that they didn’t continue any therapy. They may have switched over to tamoxifen or they may have decided they wanted to have a baby or there may have been many other things,” Dr. Francis replied, noting that analyses sorting out the reasons for early discontinuation are planned.
Session attendee Mark E. Sherman, MD, of the Mayo Clinic, Jacksonville, Fla., asked, “Do you have any ability to test for tamoxifen metabolites? It’s possible that a third to a half of patients got reduced benefit from that drug.”
Banked samples are available and a substudy is planned, according to Dr. Francis. “We haven’t got data on that yet, but yes, we are analyzing that.”
SOFT update
Initial results of the SOFT trial, reported after a median follow-up of 5.6 years, showed that adding OFS to tamoxifen did not significantly improve disease-free survival over tamoxifen alone in the entire trial population (N Engl J Med. 2015;372:436-46). However, there was benefit for women who received chemotherapy and remained premenopausal.
The updated SOFT analysis, now with a median follow-up of 8 years, focused mainly on the 1,018 women given tamoxifen alone and the 1,015 women given tamoxifen plus OFS. (Another 1,014 women were given exemestane plus OFS.)
“SOFT is now positive for its primary endpoint,” reported first author Gini Fleming, MD, director of the Medical Oncology Breast Program and medical oncology director of Gynecologic Oncology at University of Chicago Medicine. The 8-year disease-free survival rate was 83.2% with tamoxifen plus OFS, compared with 78.9% with tamoxifen alone (HR, 0.76; P = .009), corresponding to a 4.2% gain in this outcome. The relative benefit was identical whether patients had received chemotherapy or not, but absolute benefit was greater for those who had (5.3%), as well as for patients younger than 35 years (8.7%).
In addition, exemestane plus OFS was superior to tamoxifen alone (85.9% vs. 78.9%; HR, 0.65), with an absolute benefit of 7.0%. Again, absolute benefit was more pronounced among women who had received prior chemotherapy (9.0%) or were younger than 35 years (13.1%).
The relative disease-free survival benefit of tamoxifen plus OFS over tamoxifen alone was similar across most subgroups stratified by disease characteristics, but patients with HER2-positive disease derived greater relative benefit from the combination as compared with their HER2-negative counterparts (P = .04 for interaction). “When we look at the combination of exemestane plus OFS versus tamoxifen, this heterogeneity is no longer seen,” Dr. Fleming noted.
In the entire trial population, there was no significant benefit of tamoxifen plus OFS over tamoxifen alone for distant recurrence-free interval and a small, significant absolute 1.9% gain in overall survival.
“The cohort who had elected to receive no prior chemotherapy did exceedingly well regardless of therapy,” she said, with little difference in overall survival across the three arms. “There were only 24 deaths total in this cohort, and 12 of those deaths were in the setting of no distant recurrence.”
On the other hand, among the women who received chemotherapy, there were significant absolute overall survival benefits of 4.3% with tamoxifen plus OFS and 2.1% with exemestane plus OFS, over tamoxifen alone. “This late emergence of an overall survival benefit is consistent with the time course of events in estrogen receptor–positive breast cancer,” Dr. Fleming commented.
The proportion of patients who stopped their oral endocrine therapy early was 22.5% with tamoxifen alone and 18.5% with tamoxifen plus OFS. (It was 27.8% with exemestane plus OFS.) “Almost a quarter of the patients on either tamoxifen arm were using extended oral endocrine therapy at 6 years or later prior to any disease progression. Only about 12% of patients in the exemestane group were doing so,” she noted.
There were more cases of endometrial cancer with tamoxifen alone than with tamoxifen plus OFS (7 vs. 4 cases). Thrombosis/embolism of grade 2-4 occurred in 2.2% of each group (and 0.9% of the exemestane plus OFS group). Musculoskeletal symptoms of grade 3 or 4 occurred in 6.7% of patients with tamoxifen alone and 5.9% with tamoxifen plus OFS, but 12.0% with exemestane plus OFS. Respective rates of osteoporosis grade 2-4 were 3.9%, 6.1%, and 11.9%.
“The addition of OFS to tamoxifen significantly improves disease-free survival at 8 years’ median follow-up, and disease-free survival benefits are further improved by the use of exemestane plus OFS,” Dr. Fleming summarized. “Follow-up, which is critically important given the long natural history of ER-positive disease, continues.”
Session attendee Matthew P. Goetz, MD, of the Mayo Clinic, Rochester, Minn., commented, “For the primary endpoint, I was looking at the tail for tamoxifen. It seemed that there was a relatively rapid drop-off between year 5 and this 8-year follow-up. Have you looked carefully to see whether there is a difference between those who stayed on their therapy versus those who went off it per protocol? That is, extended versus not extended? The question is whether there is a carry-over effect, if you will, that is different in those with OFS versus those not.”
“The percent who went on to extended therapy between the tamoxifen and the tamoxifen plus OFS was fairly similar,” Dr. Fleming replied. “But the answer is no, we have not yet done any sort of per protocol analysis.”
Session attendee Steven Vogl, MD, of Montefiore Medical Center, New York, commented, “I worry about your control group. I’m worried, first, how many of your tamoxifen patients lost their menses and became postmenopausal in those 5 years? And of those, why didn’t they switch to an aromatase inhibitor? Only 25% of the patients continued after the 5 years according to your slide, and all of those patients should either have stayed on tamoxifen or switched to an aromatase inhibitor, now probably for 2 years at least.”
“We have not yet looked at data for who became amenorrheic during treatment, although we have it. However, it’s certainly possible to become amenorrheic on tamoxifen and not be postmenopausal, and we didn’t regularly collect estradiol levels on any but the very small subset of women in the SOFT-S trial. So I don’t know that we have exactly the data that you’re looking for,” Dr. Fleming said. “Many of these women are obviously at very, very low risk and have done well with 5 years of tamoxifen alone, and I don’t know, even given current guidelines, that extended tamoxifen would add a lot to that.”
Finally, session attendee Richard Gray, professor of medical statistics at the University of Oxford (England), wondered, “What is the certainty that follow-up will happen? Because obviously, prolonged follow-up is expensive and there are controversies about that. But this would be the one study you would really want to have 15- and 20-year data on.”
“We are working very, very hard on that,” Dr. Fleming replied. “NCI granted additional funds to institutions for prolonging follow-up, and IBCSG has been ceaselessly working to look for funding to continue it. So I think it’s relatively certain that it will happen.”
Dr. Francis disclosed that she has received fees for non-CME services from AstraZeneca and has given an overseas lecture for Pfizer. Dr. Fleming disclosed that she had no relevant financial relationships with commercial interests. The trials received financial support from Pfizer and Ipsen.
SOURCES: Francis et al. SABCS Abstract GS4-02; Fleming et al. SABCS Abstract GS4-03
REPORTING FROM SABCS 2017
Key clinical point:
Major finding: In the joint TEXT-SOFT update, 8-year disease-free survival was superior with exemestane plus OFS versus tamoxifen plus OFS (86.8% vs. 82.8%; P = .0006). In the SOFT update, 8-year disease-free survival was superior with tamoxifen plus OFS versus tamoxifen alone (83.2% vs. 78.9%; P = .009).
Data source: Updated analyses of phase 3 trials among premenopausal women with HR-positive breast cancer: TEXT and SOFT joint analysis (n = 4,690; median 9-year follow-up) and SOFT analysis (n = 3,047; median 8-year follow-up).
Disclosures: Dr. Francis disclosed that she has received fees for non-CME services from AstraZeneca and has given an overseas lecture for Pfizer. Dr. Fleming disclosed that she had no relevant financial relationships with commercial interests. The trials received financial support from Pfizer and Ipsen.
Source: Francis et al. SABCS Abstract GS4-02; Fleming et al. SABCS Abstract GS4-03
New and improved classifiers may sharpen thyroid nodule diagnosis
VICTORIA, B.C. – Several new and improved molecular classifiers show good performance for preoperatively assessing the nature of thyroid nodules, including histologic subsets that continue to pose diagnostic challenges, according to a trio of studies reported at the annual meeting of the American Thyroid Association.
ThyroSeq v3 classifier
In a prospective, blinded, multi-institutional study, investigators validated the ThyroSeq v3 genomic classifier, which uses next-generation sequencing to test for mutations, fusions, gene expression alterations, and copy number variations in 112 genes.
The validation cohort consisted of 234 patients from 10 centers who had thyroid nodules with Bethesda III to V cytology and known surgical outcome, with central pathology review, and successful molecular testing. In total, they had 257 fine needle aspiration samples.
Of the 247 samples from nodules having Bethesda III or IV cytology – those of greatest interest – 28% were cancer or noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP), reported senior author Yuri Nikiforov, MD, PhD, professor of pathology and director of the division of molecular & genomic pathology at the University of Pittsburgh Medical Center. “Both cancer and NIFTP are surgical diseases, so we felt they belong in one group,” he noted.
Among the Bethesda III or IV samples, ThyroSeq v3 had a sensitivity of 94%, a specificity of 82%, a positive predictive value of 66%, and a negative predictive value of 97%. Additional analyses showed that the test would still have a negative predictive value of 95% or better up to a cancer/NIFTP prevalence of 44%.
All five false-negative cases in the entire study cohort were intrathyroidal nodules of low stage and without aggressive histology.
Of the 33 false-positive cases, 68% were diagnosed on pathology as Hurthle cell or follicular adenomas, 10% were initially diagnosed by local pathologists as cancer or NIFTP, and 94% harbored clonal oncogenic molecular alterations.
“So, these are not actually hyperplasia; these are true tumors. Probably at least some of them would have the potential to progress,” said Dr. Nikiforov. “I believe that this so-called false-positive rate may not be really false positive. This is a rate of detection of precancerous tumors, not hyperplasia, that still may require surgical excision.”
In this study, “we found very high sensitivity and negative predictive value of ThyroSeq v3, with robust negative predictive value in populations with different disease prevalence,” he concluded. “Robust performance was achieved in many thyroid cancer types, including Hurthle cell cancer.”
All study patients underwent surgery, so it is not clear how the classifier would perform in the context of surveillance, he acknowledged. But the 97% negative predictive value gives confidence for patients having a negative result.
“Those patients very likely can be observed – not necessarily dismissed from medical surveillance, but observed – and could probably avoid surgery,” he said. “If patients have a positive test, it will depend on the type of mutation, because some of them confer a high risk and others confer low risk. So, there may be a spectrum of management based on combination of clinical parameters and molecular testing. But those are more likely to be surgical candidates.”
“This is a study that is desperately needed in this field,” session attendee Bryan McIver, MD, PhD, an endocrinologist and deputy physician-in-chief at the Moffitt Cancer Center in Tampa, said in an interview. “These are very challenging studies to do, because the marketing of these molecular tests has run ahead of a lot of the clinical studies.
“It’s very hard in the United States, at least, to find patients who are truly naive to molecular testing whom you can take to the operating room,” he explained. “And if you can’t take patients with a negative molecular test to the operating room, then you can’t actually calculate the true sensitivity and specificity of the test, and the whole evaluation of the test starts to become skewed.”
According to Dr. McIver, this study is noteworthy in that it largely fulfills four key criteria: There were no post hoc sample exclusions after unblinding of data, both pathology evaluation and decision to operate were blinded to classifier results, and patients were generally unselected, with little to no prior molecular testing.
“So, we actually have a proper high-quality validation study now available for this new test, the ThyroSeq v3,” he noted. “That sets the bar where it needed to be set a long time ago, and I can’t begin to tell you how excited I am to finally have a test that passed that bar. The fact that it shows a negative predictive value of 97% in this clinical study and a positive predictive value in the mid-60% range means that there is a potential for a clinical utility there that is backed by solid science. In this field, that’s almost unique.”
Afirma GSC with Hurthle classifiers
In a second study, investigators led by Quan-Yang Duh, MD, professor of surgery, division of general surgery, and chief, section of endocrine surgery, University of California, San Francisco, developed and validated a pair of classifiers to enhance performance of the Afirma platform among Hurthle cell specimens.
“The Hurthle cell lesions tend to give us trouble,” Dr. Duh said. On molecular analysis, those that are malignant seldom harbor mutations that would aid diagnosis, whereas those that are benign are usually classified as suspicious by the original Afirma Gene Expression Classifier (GEC).
“The specific group that is causing trouble are those that are Hurthle cell but not neoplasm, because they are the ones that give you the false positives,” Dr. Duh said. Therefore, it makes sense to stratify lesions on both of these factors, and then subject that specific subset to a more stringent threshold.
The investigators developed two classifiers that work with the Afirma core Genomic Sequencing Classifier (GSC), which uses RNA sequencing and machine learning algorithms.
The first classifier uses differential expression of 1,408 genes to determine whether a sample contains Hurthle cells. The second classifier, applied only to lesions containing Hurthle cells, uses differential expression of 2,041 genes and assesses loss of heterozygosity – which is prevalent in Hurthle cell neoplasms – to determine whether a Hurthle cell lesion is a neoplasm.
The ensemble model then makes a final classification, using a higher threshold for suspicious lesions determined to be Hurthle cell but not neoplasm, and a normal threshold for all the rest.
The investigators validated the Afirma GSC with the two classifiers in blinded fashion using 186 thyroid lesion samples having Bethesda III or IV cytology that had been part of the overall multicenter validation of the original Afirma GEC (N Engl J Med. 2012 Aug 23;367[8]:705-15).
Among the 26 Hurthle cell lesions, specificity for identifying benign lesions improved from 11.8% with the original Afirma GEC to 58.8% with the Afirma GSC and new classifiers. That was an absolute gain of 47% (P = .012), Dr. Duh reported. Sensitivity for identifying cancer was 88.9%.
There were also smaller absolute gains in specificity of 18% among all lesions in the cohort (P = .0028) and 14% among non-Hurthle lesions (P = .028).
“The new GSC test has significantly improved specificity in the patients with Bethesda III and IV specimens with Hurthle cells, and this may reduce unnecessary diagnostic surgery,” said Dr. Duh. “Basically, there are fewer false positives and more patients who can be called benign in the Hurthle cell group who would not need an operation.”
Further validation is needed, he acknowledged. “For a while, I wouldn’t send my Hurthle cell aspirate patients for Afirma, because I knew it was going to come back suspicious. I think I will start to do it now, but we need to see what the answers look like” with additional validation.
Afirma GSC with medullary thyroid cancer classifier
In a third study, investigators developed and validated a classifier for medullary thyroid cancer to be used with the Afirma GSC. They were led by Gregory Randolph, MD, professor of otolaryngology and the Claire and John Bertucci Endowed Chair in Thyroid Surgical Oncology at Harvard Medical School, and division chief of the general and thyroid/parathyroid endocrine surgical divisions at the Massachusetts Eye and Ear Infirmary, Boston.
Better preoperative identification of this cancer is key for several reasons, he maintained.
“We need to know for the timing of surgery, and for the extent of both thyroidal and nodal components of surgery,” Dr. Randolph noted. “We need to know because of the aggressive nature of these lesions and the potential to be prepared for finding invasion at surgery; for the potential of bilaterality if inherited disease is present; for the potential for parathyroid disease, if familial; and finally, for the potential for intraoperative death with unrecognized pheochromocytoma and an unprepared surgeon.”
Establishing the diagnosis from needle biopsy is challenging, because some features overlap with those of other thyroid lesions, according to Dr. Randolph. In about a third of patients with medullary thyroid cancer brought to the operating room, the diagnosis is unknown at the time, and that often results in inadequate initial surgery.
The investigators developed a medullary thyroid cancer classifier cassette that assesses differential expression of 108 genes. They then performed blinded, independent validation in a cohort of 211 fine-needle aspiration samples from thyroid nodules: 21 medullary thyroid cancers and 190 other benign and malignant neoplasms.
Results showed that the Afirma GSC with the medullary thyroid cancer classifier had sensitivity of 100% and specificity of 100%, reported Dr. Randolph.
“The Afirma GSC medullary thyroid cancer testing cassette, within the larger GSC system, uses RNA sequencing and advanced machine learning to improve the diagnostic detection of medullary thyroid cancer, which currently misses approximately a third of medullary thyroid cancer patients,” he said.
Session attendees wondered which patients are appropriate candidates and how much the test will cost.
“We have to have a discussion about that, because the missed medullaries are, frankly, widely distributed – they can be in any of the Bethesda categories, basically,” Dr. Randolph said. “So, there are cytopathologic mistakes made uniformly, including in the suspicious and frankly malignant Bethesda categories. In terms of cost, this is embedded in the GSC classifier; so, if you order that test, you will obtain this medullary cassette.”
Actual sensitivity of the classifier may ultimately be less than 100% with use in larger samples, he acknowledged. “I think a greater number of validation tests is absolutely in order. I imagine this classifier may not be perfect, but it is way better than the third we miss with just cytopathology.”
Dr. Nikiforov disclosed that he is owner of an IP for ThyroSeq, and that his laboratory has a contract to offer the test commercially. Dr. Duh disclosed that he had no relevant conflicts of interest. Dr. Randolph disclosed that he had no relevant conflicts of interest.
VICTORIA, B.C. – Several new and improved molecular classifiers show good performance for preoperatively assessing the nature of thyroid nodules, including histologic subsets that continue to pose diagnostic challenges, according to a trio of studies reported at the annual meeting of the American Thyroid Association.
ThyroSeq v3 classifier
In a prospective, blinded, multi-institutional study, investigators validated the ThyroSeq v3 genomic classifier, which uses next-generation sequencing to test for mutations, fusions, gene expression alterations, and copy number variations in 112 genes.
The validation cohort consisted of 234 patients from 10 centers who had thyroid nodules with Bethesda III to V cytology and known surgical outcome, with central pathology review, and successful molecular testing. In total, they had 257 fine needle aspiration samples.
Of the 247 samples from nodules having Bethesda III or IV cytology – those of greatest interest – 28% were cancer or noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP), reported senior author Yuri Nikiforov, MD, PhD, professor of pathology and director of the division of molecular & genomic pathology at the University of Pittsburgh Medical Center. “Both cancer and NIFTP are surgical diseases, so we felt they belong in one group,” he noted.
Among the Bethesda III or IV samples, ThyroSeq v3 had a sensitivity of 94%, a specificity of 82%, a positive predictive value of 66%, and a negative predictive value of 97%. Additional analyses showed that the test would still have a negative predictive value of 95% or better up to a cancer/NIFTP prevalence of 44%.
All five false-negative cases in the entire study cohort were intrathyroidal nodules of low stage and without aggressive histology.
Of the 33 false-positive cases, 68% were diagnosed on pathology as Hurthle cell or follicular adenomas, 10% were initially diagnosed by local pathologists as cancer or NIFTP, and 94% harbored clonal oncogenic molecular alterations.
“So, these are not actually hyperplasia; these are true tumors. Probably at least some of them would have the potential to progress,” said Dr. Nikiforov. “I believe that this so-called false-positive rate may not be really false positive. This is a rate of detection of precancerous tumors, not hyperplasia, that still may require surgical excision.”
In this study, “we found very high sensitivity and negative predictive value of ThyroSeq v3, with robust negative predictive value in populations with different disease prevalence,” he concluded. “Robust performance was achieved in many thyroid cancer types, including Hurthle cell cancer.”
All study patients underwent surgery, so it is not clear how the classifier would perform in the context of surveillance, he acknowledged. But the 97% negative predictive value gives confidence for patients having a negative result.
“Those patients very likely can be observed – not necessarily dismissed from medical surveillance, but observed – and could probably avoid surgery,” he said. “If patients have a positive test, it will depend on the type of mutation, because some of them confer a high risk and others confer low risk. So, there may be a spectrum of management based on combination of clinical parameters and molecular testing. But those are more likely to be surgical candidates.”
“This is a study that is desperately needed in this field,” session attendee Bryan McIver, MD, PhD, an endocrinologist and deputy physician-in-chief at the Moffitt Cancer Center in Tampa, said in an interview. “These are very challenging studies to do, because the marketing of these molecular tests has run ahead of a lot of the clinical studies.
“It’s very hard in the United States, at least, to find patients who are truly naive to molecular testing whom you can take to the operating room,” he explained. “And if you can’t take patients with a negative molecular test to the operating room, then you can’t actually calculate the true sensitivity and specificity of the test, and the whole evaluation of the test starts to become skewed.”
According to Dr. McIver, this study is noteworthy in that it largely fulfills four key criteria: There were no post hoc sample exclusions after unblinding of data, both pathology evaluation and decision to operate were blinded to classifier results, and patients were generally unselected, with little to no prior molecular testing.
“So, we actually have a proper high-quality validation study now available for this new test, the ThyroSeq v3,” he noted. “That sets the bar where it needed to be set a long time ago, and I can’t begin to tell you how excited I am to finally have a test that passed that bar. The fact that it shows a negative predictive value of 97% in this clinical study and a positive predictive value in the mid-60% range means that there is a potential for a clinical utility there that is backed by solid science. In this field, that’s almost unique.”
Afirma GSC with Hurthle classifiers
In a second study, investigators led by Quan-Yang Duh, MD, professor of surgery, division of general surgery, and chief, section of endocrine surgery, University of California, San Francisco, developed and validated a pair of classifiers to enhance performance of the Afirma platform among Hurthle cell specimens.
“The Hurthle cell lesions tend to give us trouble,” Dr. Duh said. On molecular analysis, those that are malignant seldom harbor mutations that would aid diagnosis, whereas those that are benign are usually classified as suspicious by the original Afirma Gene Expression Classifier (GEC).
“The specific group that is causing trouble are those that are Hurthle cell but not neoplasm, because they are the ones that give you the false positives,” Dr. Duh said. Therefore, it makes sense to stratify lesions on both of these factors, and then subject that specific subset to a more stringent threshold.
The investigators developed two classifiers that work with the Afirma core Genomic Sequencing Classifier (GSC), which uses RNA sequencing and machine learning algorithms.
The first classifier uses differential expression of 1,408 genes to determine whether a sample contains Hurthle cells. The second classifier, applied only to lesions containing Hurthle cells, uses differential expression of 2,041 genes and assesses loss of heterozygosity – which is prevalent in Hurthle cell neoplasms – to determine whether a Hurthle cell lesion is a neoplasm.
The ensemble model then makes a final classification, using a higher threshold for suspicious lesions determined to be Hurthle cell but not neoplasm, and a normal threshold for all the rest.
The investigators validated the Afirma GSC with the two classifiers in blinded fashion using 186 thyroid lesion samples having Bethesda III or IV cytology that had been part of the overall multicenter validation of the original Afirma GEC (N Engl J Med. 2012 Aug 23;367[8]:705-15).
Among the 26 Hurthle cell lesions, specificity for identifying benign lesions improved from 11.8% with the original Afirma GEC to 58.8% with the Afirma GSC and new classifiers. That was an absolute gain of 47% (P = .012), Dr. Duh reported. Sensitivity for identifying cancer was 88.9%.
There were also smaller absolute gains in specificity of 18% among all lesions in the cohort (P = .0028) and 14% among non-Hurthle lesions (P = .028).
“The new GSC test has significantly improved specificity in the patients with Bethesda III and IV specimens with Hurthle cells, and this may reduce unnecessary diagnostic surgery,” said Dr. Duh. “Basically, there are fewer false positives and more patients who can be called benign in the Hurthle cell group who would not need an operation.”
Further validation is needed, he acknowledged. “For a while, I wouldn’t send my Hurthle cell aspirate patients for Afirma, because I knew it was going to come back suspicious. I think I will start to do it now, but we need to see what the answers look like” with additional validation.
Afirma GSC with medullary thyroid cancer classifier
In a third study, investigators developed and validated a classifier for medullary thyroid cancer to be used with the Afirma GSC. They were led by Gregory Randolph, MD, professor of otolaryngology and the Claire and John Bertucci Endowed Chair in Thyroid Surgical Oncology at Harvard Medical School, and division chief of the general and thyroid/parathyroid endocrine surgical divisions at the Massachusetts Eye and Ear Infirmary, Boston.
Better preoperative identification of this cancer is key for several reasons, he maintained.
“We need to know for the timing of surgery, and for the extent of both thyroidal and nodal components of surgery,” Dr. Randolph noted. “We need to know because of the aggressive nature of these lesions and the potential to be prepared for finding invasion at surgery; for the potential of bilaterality if inherited disease is present; for the potential for parathyroid disease, if familial; and finally, for the potential for intraoperative death with unrecognized pheochromocytoma and an unprepared surgeon.”
Establishing the diagnosis from needle biopsy is challenging, because some features overlap with those of other thyroid lesions, according to Dr. Randolph. In about a third of patients with medullary thyroid cancer brought to the operating room, the diagnosis is unknown at the time, and that often results in inadequate initial surgery.
The investigators developed a medullary thyroid cancer classifier cassette that assesses differential expression of 108 genes. They then performed blinded, independent validation in a cohort of 211 fine-needle aspiration samples from thyroid nodules: 21 medullary thyroid cancers and 190 other benign and malignant neoplasms.
Results showed that the Afirma GSC with the medullary thyroid cancer classifier had sensitivity of 100% and specificity of 100%, reported Dr. Randolph.
“The Afirma GSC medullary thyroid cancer testing cassette, within the larger GSC system, uses RNA sequencing and advanced machine learning to improve the diagnostic detection of medullary thyroid cancer, which currently misses approximately a third of medullary thyroid cancer patients,” he said.
Session attendees wondered which patients are appropriate candidates and how much the test will cost.
“We have to have a discussion about that, because the missed medullaries are, frankly, widely distributed – they can be in any of the Bethesda categories, basically,” Dr. Randolph said. “So, there are cytopathologic mistakes made uniformly, including in the suspicious and frankly malignant Bethesda categories. In terms of cost, this is embedded in the GSC classifier; so, if you order that test, you will obtain this medullary cassette.”
Actual sensitivity of the classifier may ultimately be less than 100% with use in larger samples, he acknowledged. “I think a greater number of validation tests is absolutely in order. I imagine this classifier may not be perfect, but it is way better than the third we miss with just cytopathology.”
Dr. Nikiforov disclosed that he is owner of an IP for ThyroSeq, and that his laboratory has a contract to offer the test commercially. Dr. Duh disclosed that he had no relevant conflicts of interest. Dr. Randolph disclosed that he had no relevant conflicts of interest.
VICTORIA, B.C. – Several new and improved molecular classifiers show good performance for preoperatively assessing the nature of thyroid nodules, including histologic subsets that continue to pose diagnostic challenges, according to a trio of studies reported at the annual meeting of the American Thyroid Association.
ThyroSeq v3 classifier
In a prospective, blinded, multi-institutional study, investigators validated the ThyroSeq v3 genomic classifier, which uses next-generation sequencing to test for mutations, fusions, gene expression alterations, and copy number variations in 112 genes.
The validation cohort consisted of 234 patients from 10 centers who had thyroid nodules with Bethesda III to V cytology and known surgical outcome, with central pathology review, and successful molecular testing. In total, they had 257 fine needle aspiration samples.
Of the 247 samples from nodules having Bethesda III or IV cytology – those of greatest interest – 28% were cancer or noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP), reported senior author Yuri Nikiforov, MD, PhD, professor of pathology and director of the division of molecular & genomic pathology at the University of Pittsburgh Medical Center. “Both cancer and NIFTP are surgical diseases, so we felt they belong in one group,” he noted.
Among the Bethesda III or IV samples, ThyroSeq v3 had a sensitivity of 94%, a specificity of 82%, a positive predictive value of 66%, and a negative predictive value of 97%. Additional analyses showed that the test would still have a negative predictive value of 95% or better up to a cancer/NIFTP prevalence of 44%.
All five false-negative cases in the entire study cohort were intrathyroidal nodules of low stage and without aggressive histology.
Of the 33 false-positive cases, 68% were diagnosed on pathology as Hurthle cell or follicular adenomas, 10% were initially diagnosed by local pathologists as cancer or NIFTP, and 94% harbored clonal oncogenic molecular alterations.
“So, these are not actually hyperplasia; these are true tumors. Probably at least some of them would have the potential to progress,” said Dr. Nikiforov. “I believe that this so-called false-positive rate may not be really false positive. This is a rate of detection of precancerous tumors, not hyperplasia, that still may require surgical excision.”
In this study, “we found very high sensitivity and negative predictive value of ThyroSeq v3, with robust negative predictive value in populations with different disease prevalence,” he concluded. “Robust performance was achieved in many thyroid cancer types, including Hurthle cell cancer.”
All study patients underwent surgery, so it is not clear how the classifier would perform in the context of surveillance, he acknowledged. But the 97% negative predictive value gives confidence for patients having a negative result.
“Those patients very likely can be observed – not necessarily dismissed from medical surveillance, but observed – and could probably avoid surgery,” he said. “If patients have a positive test, it will depend on the type of mutation, because some of them confer a high risk and others confer low risk. So, there may be a spectrum of management based on combination of clinical parameters and molecular testing. But those are more likely to be surgical candidates.”
“This is a study that is desperately needed in this field,” session attendee Bryan McIver, MD, PhD, an endocrinologist and deputy physician-in-chief at the Moffitt Cancer Center in Tampa, said in an interview. “These are very challenging studies to do, because the marketing of these molecular tests has run ahead of a lot of the clinical studies.
“It’s very hard in the United States, at least, to find patients who are truly naive to molecular testing whom you can take to the operating room,” he explained. “And if you can’t take patients with a negative molecular test to the operating room, then you can’t actually calculate the true sensitivity and specificity of the test, and the whole evaluation of the test starts to become skewed.”
According to Dr. McIver, this study is noteworthy in that it largely fulfills four key criteria: There were no post hoc sample exclusions after unblinding of data, both pathology evaluation and decision to operate were blinded to classifier results, and patients were generally unselected, with little to no prior molecular testing.
“So, we actually have a proper high-quality validation study now available for this new test, the ThyroSeq v3,” he noted. “That sets the bar where it needed to be set a long time ago, and I can’t begin to tell you how excited I am to finally have a test that passed that bar. The fact that it shows a negative predictive value of 97% in this clinical study and a positive predictive value in the mid-60% range means that there is a potential for a clinical utility there that is backed by solid science. In this field, that’s almost unique.”
Afirma GSC with Hurthle classifiers
In a second study, investigators led by Quan-Yang Duh, MD, professor of surgery, division of general surgery, and chief, section of endocrine surgery, University of California, San Francisco, developed and validated a pair of classifiers to enhance performance of the Afirma platform among Hurthle cell specimens.
“The Hurthle cell lesions tend to give us trouble,” Dr. Duh said. On molecular analysis, those that are malignant seldom harbor mutations that would aid diagnosis, whereas those that are benign are usually classified as suspicious by the original Afirma Gene Expression Classifier (GEC).
“The specific group that is causing trouble are those that are Hurthle cell but not neoplasm, because they are the ones that give you the false positives,” Dr. Duh said. Therefore, it makes sense to stratify lesions on both of these factors, and then subject that specific subset to a more stringent threshold.
The investigators developed two classifiers that work with the Afirma core Genomic Sequencing Classifier (GSC), which uses RNA sequencing and machine learning algorithms.
The first classifier uses differential expression of 1,408 genes to determine whether a sample contains Hurthle cells. The second classifier, applied only to lesions containing Hurthle cells, uses differential expression of 2,041 genes and assesses loss of heterozygosity – which is prevalent in Hurthle cell neoplasms – to determine whether a Hurthle cell lesion is a neoplasm.
The ensemble model then makes a final classification, using a higher threshold for suspicious lesions determined to be Hurthle cell but not neoplasm, and a normal threshold for all the rest.
The investigators validated the Afirma GSC with the two classifiers in blinded fashion using 186 thyroid lesion samples having Bethesda III or IV cytology that had been part of the overall multicenter validation of the original Afirma GEC (N Engl J Med. 2012 Aug 23;367[8]:705-15).
Among the 26 Hurthle cell lesions, specificity for identifying benign lesions improved from 11.8% with the original Afirma GEC to 58.8% with the Afirma GSC and new classifiers. That was an absolute gain of 47% (P = .012), Dr. Duh reported. Sensitivity for identifying cancer was 88.9%.
There were also smaller absolute gains in specificity of 18% among all lesions in the cohort (P = .0028) and 14% among non-Hurthle lesions (P = .028).
“The new GSC test has significantly improved specificity in the patients with Bethesda III and IV specimens with Hurthle cells, and this may reduce unnecessary diagnostic surgery,” said Dr. Duh. “Basically, there are fewer false positives and more patients who can be called benign in the Hurthle cell group who would not need an operation.”
Further validation is needed, he acknowledged. “For a while, I wouldn’t send my Hurthle cell aspirate patients for Afirma, because I knew it was going to come back suspicious. I think I will start to do it now, but we need to see what the answers look like” with additional validation.
Afirma GSC with medullary thyroid cancer classifier
In a third study, investigators developed and validated a classifier for medullary thyroid cancer to be used with the Afirma GSC. They were led by Gregory Randolph, MD, professor of otolaryngology and the Claire and John Bertucci Endowed Chair in Thyroid Surgical Oncology at Harvard Medical School, and division chief of the general and thyroid/parathyroid endocrine surgical divisions at the Massachusetts Eye and Ear Infirmary, Boston.
Better preoperative identification of this cancer is key for several reasons, he maintained.
“We need to know for the timing of surgery, and for the extent of both thyroidal and nodal components of surgery,” Dr. Randolph noted. “We need to know because of the aggressive nature of these lesions and the potential to be prepared for finding invasion at surgery; for the potential of bilaterality if inherited disease is present; for the potential for parathyroid disease, if familial; and finally, for the potential for intraoperative death with unrecognized pheochromocytoma and an unprepared surgeon.”
Establishing the diagnosis from needle biopsy is challenging, because some features overlap with those of other thyroid lesions, according to Dr. Randolph. In about a third of patients with medullary thyroid cancer brought to the operating room, the diagnosis is unknown at the time, and that often results in inadequate initial surgery.
The investigators developed a medullary thyroid cancer classifier cassette that assesses differential expression of 108 genes. They then performed blinded, independent validation in a cohort of 211 fine-needle aspiration samples from thyroid nodules: 21 medullary thyroid cancers and 190 other benign and malignant neoplasms.
Results showed that the Afirma GSC with the medullary thyroid cancer classifier had sensitivity of 100% and specificity of 100%, reported Dr. Randolph.
“The Afirma GSC medullary thyroid cancer testing cassette, within the larger GSC system, uses RNA sequencing and advanced machine learning to improve the diagnostic detection of medullary thyroid cancer, which currently misses approximately a third of medullary thyroid cancer patients,” he said.
Session attendees wondered which patients are appropriate candidates and how much the test will cost.
“We have to have a discussion about that, because the missed medullaries are, frankly, widely distributed – they can be in any of the Bethesda categories, basically,” Dr. Randolph said. “So, there are cytopathologic mistakes made uniformly, including in the suspicious and frankly malignant Bethesda categories. In terms of cost, this is embedded in the GSC classifier; so, if you order that test, you will obtain this medullary cassette.”
Actual sensitivity of the classifier may ultimately be less than 100% with use in larger samples, he acknowledged. “I think a greater number of validation tests is absolutely in order. I imagine this classifier may not be perfect, but it is way better than the third we miss with just cytopathology.”
Dr. Nikiforov disclosed that he is owner of an IP for ThyroSeq, and that his laboratory has a contract to offer the test commercially. Dr. Duh disclosed that he had no relevant conflicts of interest. Dr. Randolph disclosed that he had no relevant conflicts of interest.
AT ATA 2017
Key clinical point:
Major finding: ThyroSeq v3 had a negative predictive value of 97%. Specificity was an absolute 47% greater for Afirma GSC with Hurthle-specific classifiers than for Afirma GEC. The Afirma GSC with a medullary thyroid cancer classifier had 100% sensitivity and specificity.
Data source: Validation studies of the ThyroSeq v3 classifier (257 samples), the Afirma GSC with Hurthle-specific classifiers (186 samples), and the Afirma GSC with a medullary thyroid cancer classifier (211 samples).
Disclosures: Dr. Nikiforov disclosed that he is owner of an IP for ThyroSeq, and that his laboratory has a contract to offer the test commercially. Dr. Duh disclosed that he had no relevant conflicts of interest. Dr. Randolph disclosed that he had no relevant conflicts of interest.
New tool predicts late distant recurrence of postmenopausal ER+ breast cancer
SAN ANTONIO – A new prognostic tool that uses four clinical and pathological variables may help to guide decisions about extending adjuvant endocrine therapy for postmenopausal women with estrogen receptor–positive (ER+) breast cancer, according to a study reported at the San Antonio Breast Cancer Symposium.
ER+ breast cancer is well known for recurring long after endocrine therapy stops, but the risk varies widely, ranging from 10% to 40% (N Engl J Med. 2017;377:1836-46), noted lead investigator Ivana Sestak, MS, PhD, a lecturer in medical statistics at the Queen Mary University of London. “A few trials have shown that extended endocrine therapy can reduce the risk of recurrence, but careful assessment of potential side effects and actual risk of developing a late distant recurrence is essential,” she said.
The investigators developed and validated the new tool – called the Clinical Treatment Score post-5 years (CTS5) – among 11,446 postmenopausal women treated for ER+ breast cancer (with or without chemotherapy) who had completed 5 years of adjuvant endocrine therapy without any distant recurrence on the randomized ATAC and BIG 1-98 trials.
The investigators used the CTS5 to stratify patients into a low-risk group (risk of late distant recurrence less than 5%), an intermediate-risk group (risk between 5% and 10%), and a high-risk group (risk more than 10%). The observed rates of distant recurrence between years 5 and 10 were about 3% for the low-risk group, 7% for the intermediate-risk group, and 19% for the high risk-group. In addition, the CTS5 outperformed the original Clinical Treatment Score (CTS0), which was developed to predict recurrence between 0 and 10 years (J Clin Oncol. 2011;29:4273-8).
“We have developed a simple prognostic tool for the prediction of late distant recurrences which will help clinicians and their patients in the decision-making process about extended endocrine therapy,” Dr. Sestak commented. “The CTS5 was highly prognostic for the prediction of late distant recurrences and identified a large proportion of women, 42%, as low risk, where the value of extended endocrine therapy is limited. The CTS5 was also more prognostic than the already published CTS0 and should be used in this context for the prediction of late distant recurrence.”
“We aim to make the CTS5 algorithm and risk curve, with a read-out table, available to clinicians, and it will also be published in our manuscript,” she added.
Session attendee Frankie Ann Holmes, MD, of the Texas Oncology/US Oncology Network in Houston commented, “Just identifying high risk doesn’t necessarily translate into benefit, which is what we see with the Breast Cancer Index: You get the high risk, but then you learn if there is actually benefit to the extended therapy. Does your assay have a benefit portion to it?”
“No, we can’t look at the predictive benefit [with the CTS5]. This assay is purely a prognostic tool to predict late distant recurrences,” Dr. Sestak replied. “In these two trials, we do not have information on how many patients actually went on to extended endocrine therapy. You have to remember, these are old trials – they finished in about 2007-2008 – so not many women would have been given extended endocrine therapy at that time point.”
Session attendee Laura J. van’t Veer, PhD, of the University of California, San Francisco, asked, “How do you feel this will translate for risk up to 20 years, for which the question of extended endocrine therapy might also be very relevant?”
“For the purpose of this analysis, we only looked at out to 10 years. But I agree, it’s also important if we could apply a prognostic tool out to 20 years,” Dr. Sestak replied. “We have longer follow-up on some of the ATAC women, and we might look into that to see if we see any benefit of using a prognostic tool in the prediction of late distant recurrences.”
Study details
The investigators developed and trained the new tool using data from 4,735 women from the ATAC trial. They then validated the tool using data from 6,711 women from the BIG 1-98 trial.
The final CTS5 model contained four clinical variables, Dr. Sestak reported: number of involved nodes, size of the tumor, grade of the tumor, and age of the patient.
In the ATAC population, the CTS5 model did a better job than the original CTS0 model of predicting late distant recurrence. CTS5 improved the prediction of late distant recurrence by a factor of 2.47, whereas CTS0 improved the predictive value by a factor of 2.04. The CTS5 model performed similarly well regardless of whether patients had received chemotherapy.
In the BIG 1-98 population, the findings were much the same: The CTS5 model improved prediction of late distant recurrence by 2.07, while the CTS0 model improved prediction of late distant recurrence by 1.84. Performance of the CTS5 model was again similarly good regardless of whether patients had received chemotherapy.
Observed rates of distant recurrence between years 5 and 10 were similar in the ATAC and BIG 1-98 populations for the CTS5-defined low-risk group (2.5% and 3.0%, respectively), intermediate-risk group (7.7% and 6.9%), and the high-risk group (20.3% and 17.3%).
When the two trials’ populations were combined, the observed rate was 3.0% in the CTS5-defined low-risk group, 7.3% in the intermediate-risk group, and 18.9% in the high-risk group.
In addition, the main results held up among all node-negative women combined and among all women who had between one and three positive nodes combined. “For women with four or more positive lymph nodes, the CTS5 was not informative and categorized virtually all women into the high-risk group,” Dr. Sestak noted.
The investigators did not look at whether local or regional recurrences modulated the risk of late distant recurrence, she said. However, women who had experienced isolated local recurrence during the first 5 years would have been included in analysis.
“A strength of our study is that we used clinicopathological parameters that are measured in all breast cancer patients, and there is no need for further testing,” noted Dr. Sestak, who disclosed that she has received fees for advisory boards and lectures from Myriad Genetics.
On the other hand, it is unclear how the CTS5 would perform among premenopausal women and among women with HER2-positive disease given that two trials took place before routine HER2 testing and HER2-directed therapy were used.
SOURCE: Sestak I et al. SABCS 2017 Abstract GS6-01.
SAN ANTONIO – A new prognostic tool that uses four clinical and pathological variables may help to guide decisions about extending adjuvant endocrine therapy for postmenopausal women with estrogen receptor–positive (ER+) breast cancer, according to a study reported at the San Antonio Breast Cancer Symposium.
ER+ breast cancer is well known for recurring long after endocrine therapy stops, but the risk varies widely, ranging from 10% to 40% (N Engl J Med. 2017;377:1836-46), noted lead investigator Ivana Sestak, MS, PhD, a lecturer in medical statistics at the Queen Mary University of London. “A few trials have shown that extended endocrine therapy can reduce the risk of recurrence, but careful assessment of potential side effects and actual risk of developing a late distant recurrence is essential,” she said.
The investigators developed and validated the new tool – called the Clinical Treatment Score post-5 years (CTS5) – among 11,446 postmenopausal women treated for ER+ breast cancer (with or without chemotherapy) who had completed 5 years of adjuvant endocrine therapy without any distant recurrence on the randomized ATAC and BIG 1-98 trials.
The investigators used the CTS5 to stratify patients into a low-risk group (risk of late distant recurrence less than 5%), an intermediate-risk group (risk between 5% and 10%), and a high-risk group (risk more than 10%). The observed rates of distant recurrence between years 5 and 10 were about 3% for the low-risk group, 7% for the intermediate-risk group, and 19% for the high risk-group. In addition, the CTS5 outperformed the original Clinical Treatment Score (CTS0), which was developed to predict recurrence between 0 and 10 years (J Clin Oncol. 2011;29:4273-8).
“We have developed a simple prognostic tool for the prediction of late distant recurrences which will help clinicians and their patients in the decision-making process about extended endocrine therapy,” Dr. Sestak commented. “The CTS5 was highly prognostic for the prediction of late distant recurrences and identified a large proportion of women, 42%, as low risk, where the value of extended endocrine therapy is limited. The CTS5 was also more prognostic than the already published CTS0 and should be used in this context for the prediction of late distant recurrence.”
“We aim to make the CTS5 algorithm and risk curve, with a read-out table, available to clinicians, and it will also be published in our manuscript,” she added.
Session attendee Frankie Ann Holmes, MD, of the Texas Oncology/US Oncology Network in Houston commented, “Just identifying high risk doesn’t necessarily translate into benefit, which is what we see with the Breast Cancer Index: You get the high risk, but then you learn if there is actually benefit to the extended therapy. Does your assay have a benefit portion to it?”
“No, we can’t look at the predictive benefit [with the CTS5]. This assay is purely a prognostic tool to predict late distant recurrences,” Dr. Sestak replied. “In these two trials, we do not have information on how many patients actually went on to extended endocrine therapy. You have to remember, these are old trials – they finished in about 2007-2008 – so not many women would have been given extended endocrine therapy at that time point.”
Session attendee Laura J. van’t Veer, PhD, of the University of California, San Francisco, asked, “How do you feel this will translate for risk up to 20 years, for which the question of extended endocrine therapy might also be very relevant?”
“For the purpose of this analysis, we only looked at out to 10 years. But I agree, it’s also important if we could apply a prognostic tool out to 20 years,” Dr. Sestak replied. “We have longer follow-up on some of the ATAC women, and we might look into that to see if we see any benefit of using a prognostic tool in the prediction of late distant recurrences.”
Study details
The investigators developed and trained the new tool using data from 4,735 women from the ATAC trial. They then validated the tool using data from 6,711 women from the BIG 1-98 trial.
The final CTS5 model contained four clinical variables, Dr. Sestak reported: number of involved nodes, size of the tumor, grade of the tumor, and age of the patient.
In the ATAC population, the CTS5 model did a better job than the original CTS0 model of predicting late distant recurrence. CTS5 improved the prediction of late distant recurrence by a factor of 2.47, whereas CTS0 improved the predictive value by a factor of 2.04. The CTS5 model performed similarly well regardless of whether patients had received chemotherapy.
In the BIG 1-98 population, the findings were much the same: The CTS5 model improved prediction of late distant recurrence by 2.07, while the CTS0 model improved prediction of late distant recurrence by 1.84. Performance of the CTS5 model was again similarly good regardless of whether patients had received chemotherapy.
Observed rates of distant recurrence between years 5 and 10 were similar in the ATAC and BIG 1-98 populations for the CTS5-defined low-risk group (2.5% and 3.0%, respectively), intermediate-risk group (7.7% and 6.9%), and the high-risk group (20.3% and 17.3%).
When the two trials’ populations were combined, the observed rate was 3.0% in the CTS5-defined low-risk group, 7.3% in the intermediate-risk group, and 18.9% in the high-risk group.
In addition, the main results held up among all node-negative women combined and among all women who had between one and three positive nodes combined. “For women with four or more positive lymph nodes, the CTS5 was not informative and categorized virtually all women into the high-risk group,” Dr. Sestak noted.
The investigators did not look at whether local or regional recurrences modulated the risk of late distant recurrence, she said. However, women who had experienced isolated local recurrence during the first 5 years would have been included in analysis.
“A strength of our study is that we used clinicopathological parameters that are measured in all breast cancer patients, and there is no need for further testing,” noted Dr. Sestak, who disclosed that she has received fees for advisory boards and lectures from Myriad Genetics.
On the other hand, it is unclear how the CTS5 would perform among premenopausal women and among women with HER2-positive disease given that two trials took place before routine HER2 testing and HER2-directed therapy were used.
SOURCE: Sestak I et al. SABCS 2017 Abstract GS6-01.
SAN ANTONIO – A new prognostic tool that uses four clinical and pathological variables may help to guide decisions about extending adjuvant endocrine therapy for postmenopausal women with estrogen receptor–positive (ER+) breast cancer, according to a study reported at the San Antonio Breast Cancer Symposium.
ER+ breast cancer is well known for recurring long after endocrine therapy stops, but the risk varies widely, ranging from 10% to 40% (N Engl J Med. 2017;377:1836-46), noted lead investigator Ivana Sestak, MS, PhD, a lecturer in medical statistics at the Queen Mary University of London. “A few trials have shown that extended endocrine therapy can reduce the risk of recurrence, but careful assessment of potential side effects and actual risk of developing a late distant recurrence is essential,” she said.
The investigators developed and validated the new tool – called the Clinical Treatment Score post-5 years (CTS5) – among 11,446 postmenopausal women treated for ER+ breast cancer (with or without chemotherapy) who had completed 5 years of adjuvant endocrine therapy without any distant recurrence on the randomized ATAC and BIG 1-98 trials.
The investigators used the CTS5 to stratify patients into a low-risk group (risk of late distant recurrence less than 5%), an intermediate-risk group (risk between 5% and 10%), and a high-risk group (risk more than 10%). The observed rates of distant recurrence between years 5 and 10 were about 3% for the low-risk group, 7% for the intermediate-risk group, and 19% for the high risk-group. In addition, the CTS5 outperformed the original Clinical Treatment Score (CTS0), which was developed to predict recurrence between 0 and 10 years (J Clin Oncol. 2011;29:4273-8).
“We have developed a simple prognostic tool for the prediction of late distant recurrences which will help clinicians and their patients in the decision-making process about extended endocrine therapy,” Dr. Sestak commented. “The CTS5 was highly prognostic for the prediction of late distant recurrences and identified a large proportion of women, 42%, as low risk, where the value of extended endocrine therapy is limited. The CTS5 was also more prognostic than the already published CTS0 and should be used in this context for the prediction of late distant recurrence.”
“We aim to make the CTS5 algorithm and risk curve, with a read-out table, available to clinicians, and it will also be published in our manuscript,” she added.
Session attendee Frankie Ann Holmes, MD, of the Texas Oncology/US Oncology Network in Houston commented, “Just identifying high risk doesn’t necessarily translate into benefit, which is what we see with the Breast Cancer Index: You get the high risk, but then you learn if there is actually benefit to the extended therapy. Does your assay have a benefit portion to it?”
“No, we can’t look at the predictive benefit [with the CTS5]. This assay is purely a prognostic tool to predict late distant recurrences,” Dr. Sestak replied. “In these two trials, we do not have information on how many patients actually went on to extended endocrine therapy. You have to remember, these are old trials – they finished in about 2007-2008 – so not many women would have been given extended endocrine therapy at that time point.”
Session attendee Laura J. van’t Veer, PhD, of the University of California, San Francisco, asked, “How do you feel this will translate for risk up to 20 years, for which the question of extended endocrine therapy might also be very relevant?”
“For the purpose of this analysis, we only looked at out to 10 years. But I agree, it’s also important if we could apply a prognostic tool out to 20 years,” Dr. Sestak replied. “We have longer follow-up on some of the ATAC women, and we might look into that to see if we see any benefit of using a prognostic tool in the prediction of late distant recurrences.”
Study details
The investigators developed and trained the new tool using data from 4,735 women from the ATAC trial. They then validated the tool using data from 6,711 women from the BIG 1-98 trial.
The final CTS5 model contained four clinical variables, Dr. Sestak reported: number of involved nodes, size of the tumor, grade of the tumor, and age of the patient.
In the ATAC population, the CTS5 model did a better job than the original CTS0 model of predicting late distant recurrence. CTS5 improved the prediction of late distant recurrence by a factor of 2.47, whereas CTS0 improved the predictive value by a factor of 2.04. The CTS5 model performed similarly well regardless of whether patients had received chemotherapy.
In the BIG 1-98 population, the findings were much the same: The CTS5 model improved prediction of late distant recurrence by 2.07, while the CTS0 model improved prediction of late distant recurrence by 1.84. Performance of the CTS5 model was again similarly good regardless of whether patients had received chemotherapy.
Observed rates of distant recurrence between years 5 and 10 were similar in the ATAC and BIG 1-98 populations for the CTS5-defined low-risk group (2.5% and 3.0%, respectively), intermediate-risk group (7.7% and 6.9%), and the high-risk group (20.3% and 17.3%).
When the two trials’ populations were combined, the observed rate was 3.0% in the CTS5-defined low-risk group, 7.3% in the intermediate-risk group, and 18.9% in the high-risk group.
In addition, the main results held up among all node-negative women combined and among all women who had between one and three positive nodes combined. “For women with four or more positive lymph nodes, the CTS5 was not informative and categorized virtually all women into the high-risk group,” Dr. Sestak noted.
The investigators did not look at whether local or regional recurrences modulated the risk of late distant recurrence, she said. However, women who had experienced isolated local recurrence during the first 5 years would have been included in analysis.
“A strength of our study is that we used clinicopathological parameters that are measured in all breast cancer patients, and there is no need for further testing,” noted Dr. Sestak, who disclosed that she has received fees for advisory boards and lectures from Myriad Genetics.
On the other hand, it is unclear how the CTS5 would perform among premenopausal women and among women with HER2-positive disease given that two trials took place before routine HER2 testing and HER2-directed therapy were used.
SOURCE: Sestak I et al. SABCS 2017 Abstract GS6-01.
REPORTING FROM SABCS 2017
Key clinical point:
Major finding: The tool stratified patients for risk of distant recurrence between years 5 and 10 as low risk (less than 5% risk), intermediate risk (5%-10% risk), and high risk (more than 10% risk).
Data source: A cohort study of 11,446 postmenopausal women with early-stage breast cancer who were free of distant recurrence after 5 years of adjuvant endocrine therapy.
Disclosures: Dr. Sestak disclosed that she has received fees for advisory boards and lectures from Myriad Genetics.
Source: Sestak I et al. SABCS 2017 Abstract GS6-01.
EndoPredict results reflected tumor response to neoadjuvant therapy
SAN ANTONIO – The results of the EndoPredict test appear to predict tumor response in patients with early hormone receptor–positive, HER2-negative breast cancer given neoadjuvant therapy, based on results of a study conducted by the Austrian Breast & Colorectal Cancer Study Group (ABCSG).
“Very good tumor shrinkage in estrogen receptor–positive, HER2-negative disease is going to happen only in a minority of patients, and biomarkers that would predict excellent tumor shrinkage are an unmet medical need,” commented lead investigator Peter Dubsky, MD, PhD, who is head of the Breast Center at Hirslanden Klinik St. Anna, Lucerne, Switzerland. “As a surgeon, that would help me to predict breast conservation at diagnosis, but as a surgical oncologist, I would also recognize that tumor response is an important component of future survival.”
The ABCSG findings suggest expanded utility for EndoPredict. The test’s molecular score is currently used along with tumor size and nodal status to predict the 10-year distant recurrence rate, and whether patients may safely forgo chemotherapy or are at high risk and may need adjuvant chemotherapy in addition to endocrine therapy.
Dr. Dubsky and his coinvestigators assessed performance of the EndoPredict test among 217 patients treated on ABCSG 34, a randomized phase 2 neoadjuvant trial. Findings showed that among patients given neoadjuvant endocrine therapy because they had less aggressive disease features, an EndoPredict high-risk result was associated with poor response (negative predictive value of 92%), defined as a residual cancer burden (RCB) of II or III, he reported at the San Antonio Breast Cancer Symposium.
On the other hand, among patients given neoadjuvant chemotherapy because they had more aggressive disease features, a low-risk result was associated with poor response (negative predictive value of 100%).
“Clinicians really gave us two distinct cohorts within ABCSG 34. In the luminal A–type patients who were treated with neoendocrine therapy, a high EndoPredict score predicted a low chance of tumor shrinkage. In the more aggressive ER-positive tumors, so-called luminal B type, treated with neoadjuvant chemotherapy, there was absolutely no excellent response in the low-risk group,” Dr. Dubsky summarized. “We believe that this molecular score may contribute to patient selection for biomarker-driven studies, especially in the neoadjuvant setting.”
Session attendee Steven Vogl, MD, a medical oncologist with the Montefiore Medical Center in New York, commented, “I have trouble correlating an RCB of 0 or I with what you as a surgeon do for the patient, because you are talking about pathologic complete response or just a few cells there. That’s not what determines how much breast you take off: It’s determined by the total size of the tumor and the size of the breast. So if it’s less than a few centimeters, I’m sure you can do a lumpectomy in every patient. Tell me why I should care that you are getting an RCB of 0 or I in these endocrine patients.”
“Because it’s more likely that these patients will have a smaller tumor and better tumor shrinkage,” Dr. Dubsky replied. “You are of course right, RCB 0 or I was not designed to help surgeons. But it helps me as a translational scientist to have a surrogate and an exact classification for good tumor shrinkage. That’s how I used it.”
C. Kent Osborne, MD, codirector of SABCS and director of the Dan L. Duncan Cancer Center at Baylor College of Medicine in Houston, asked, “We see it in the clinic, and I’m sure you have as well, patients whose tumor doesn’t shrink very much, but the Ki-67 really drops. And that may or may not be a better factor than the actual tumor shrinkage. So how many patients who had tumors that didn’t shrink, which was your endpoint, had a reduction in Ki-67 that was, say, 5%?”
“We haven’t looked at that specifically, but we will do so as we carry on with the follow-up of these patients. Then we can learn more about the prognosis,” Dr. Dubsky replied.
Study details
ABCSG 34 was a randomized phase 2 trial testing addition of the cancer vaccine tecemotide (Stimuvax) to neoadjuvant standard of care among patients with HER2-negative early breast cancer.
Dr. Dubsky and coinvestigators restricted analyses to patients with hormone receptor–positive disease who, depending on clinical and pathologic factors, received neoadjuvant chemotherapy (eight cycles of epirubicin-cyclophosphamide and docetaxel) or neoadjuvant endocrine therapy (6 months of letrozole [Femara]) as standard of care. They were then randomized to additionally receive tecemotide or not before undergoing surgery.
Overall, 25% of the 134 patients in the neoadjuvant chemotherapy group had a good tumor response, defined as pathologic complete response in both breast and nodes (RCB of 0) or minimal residual disease (RCB of I).
Higher EndoPredict score was associated with greater likelihood of good response to chemotherapy. EndoPredict risk group (high vs. low) had a negative predictive value of 100%, a positive predictive value of 26.4%, a true-positive rate of 100%, and a true-negative rate of 8.9% for predicting response (P = .112).
Area under the receiver operating characteristic curve was 0.736.
In a multivariate model, EndoPredict score as a continuous variable was not an independent predictor of response. “The good response was largely driven by covariates that included cell proliferation, and it was Ki-67 that was significant,” Dr. Dubsky noted.
Overall, 18% of the 83 patients in the neoadjuvant endocrine therapy group had a good tumor response (RCB of 0 or I). Here, lower EndoPredict score was associated with greater likelihood of good response. EndoPredict risk group (high vs. low) had a negative predictive value of 92.3%, a positive predictive value of 27.3%, a true-positive rate of 80.0%, and a true-negative rate of 52.9% for predicting response (P = .024). Area under the curve was 0.726.
In a multivariate model here, EndoPredict score as a continuous variable, its estrogen receptor–signaling/differentiation component, and Ki-67 did not independently predict response. “It was maybe a bit surprising that T stage was the strongest factor, possibly indicating that we should have simply treated those women longer than 6 months,” Dr. Dubsky commented. The EndoPredict proliferation component was also a significant predictor.
“Possibly, the very narrow distribution of Ki-67 [among patients given neoendocrine therapy] may have prevented this factor from playing a bigger role in this particular model,” he speculated.
Dr. Dubsky disclosed that he receives consulting fees from Myriad, the maker of EndoPredict, and from Cepheid, Nanostring, and Amgen.
SOURCE: Dubsky P et al. SABCS 2017 Abstract GS6-04.
SAN ANTONIO – The results of the EndoPredict test appear to predict tumor response in patients with early hormone receptor–positive, HER2-negative breast cancer given neoadjuvant therapy, based on results of a study conducted by the Austrian Breast & Colorectal Cancer Study Group (ABCSG).
“Very good tumor shrinkage in estrogen receptor–positive, HER2-negative disease is going to happen only in a minority of patients, and biomarkers that would predict excellent tumor shrinkage are an unmet medical need,” commented lead investigator Peter Dubsky, MD, PhD, who is head of the Breast Center at Hirslanden Klinik St. Anna, Lucerne, Switzerland. “As a surgeon, that would help me to predict breast conservation at diagnosis, but as a surgical oncologist, I would also recognize that tumor response is an important component of future survival.”
The ABCSG findings suggest expanded utility for EndoPredict. The test’s molecular score is currently used along with tumor size and nodal status to predict the 10-year distant recurrence rate, and whether patients may safely forgo chemotherapy or are at high risk and may need adjuvant chemotherapy in addition to endocrine therapy.
Dr. Dubsky and his coinvestigators assessed performance of the EndoPredict test among 217 patients treated on ABCSG 34, a randomized phase 2 neoadjuvant trial. Findings showed that among patients given neoadjuvant endocrine therapy because they had less aggressive disease features, an EndoPredict high-risk result was associated with poor response (negative predictive value of 92%), defined as a residual cancer burden (RCB) of II or III, he reported at the San Antonio Breast Cancer Symposium.
On the other hand, among patients given neoadjuvant chemotherapy because they had more aggressive disease features, a low-risk result was associated with poor response (negative predictive value of 100%).
“Clinicians really gave us two distinct cohorts within ABCSG 34. In the luminal A–type patients who were treated with neoendocrine therapy, a high EndoPredict score predicted a low chance of tumor shrinkage. In the more aggressive ER-positive tumors, so-called luminal B type, treated with neoadjuvant chemotherapy, there was absolutely no excellent response in the low-risk group,” Dr. Dubsky summarized. “We believe that this molecular score may contribute to patient selection for biomarker-driven studies, especially in the neoadjuvant setting.”
Session attendee Steven Vogl, MD, a medical oncologist with the Montefiore Medical Center in New York, commented, “I have trouble correlating an RCB of 0 or I with what you as a surgeon do for the patient, because you are talking about pathologic complete response or just a few cells there. That’s not what determines how much breast you take off: It’s determined by the total size of the tumor and the size of the breast. So if it’s less than a few centimeters, I’m sure you can do a lumpectomy in every patient. Tell me why I should care that you are getting an RCB of 0 or I in these endocrine patients.”
“Because it’s more likely that these patients will have a smaller tumor and better tumor shrinkage,” Dr. Dubsky replied. “You are of course right, RCB 0 or I was not designed to help surgeons. But it helps me as a translational scientist to have a surrogate and an exact classification for good tumor shrinkage. That’s how I used it.”
C. Kent Osborne, MD, codirector of SABCS and director of the Dan L. Duncan Cancer Center at Baylor College of Medicine in Houston, asked, “We see it in the clinic, and I’m sure you have as well, patients whose tumor doesn’t shrink very much, but the Ki-67 really drops. And that may or may not be a better factor than the actual tumor shrinkage. So how many patients who had tumors that didn’t shrink, which was your endpoint, had a reduction in Ki-67 that was, say, 5%?”
“We haven’t looked at that specifically, but we will do so as we carry on with the follow-up of these patients. Then we can learn more about the prognosis,” Dr. Dubsky replied.
Study details
ABCSG 34 was a randomized phase 2 trial testing addition of the cancer vaccine tecemotide (Stimuvax) to neoadjuvant standard of care among patients with HER2-negative early breast cancer.
Dr. Dubsky and coinvestigators restricted analyses to patients with hormone receptor–positive disease who, depending on clinical and pathologic factors, received neoadjuvant chemotherapy (eight cycles of epirubicin-cyclophosphamide and docetaxel) or neoadjuvant endocrine therapy (6 months of letrozole [Femara]) as standard of care. They were then randomized to additionally receive tecemotide or not before undergoing surgery.
Overall, 25% of the 134 patients in the neoadjuvant chemotherapy group had a good tumor response, defined as pathologic complete response in both breast and nodes (RCB of 0) or minimal residual disease (RCB of I).
Higher EndoPredict score was associated with greater likelihood of good response to chemotherapy. EndoPredict risk group (high vs. low) had a negative predictive value of 100%, a positive predictive value of 26.4%, a true-positive rate of 100%, and a true-negative rate of 8.9% for predicting response (P = .112).
Area under the receiver operating characteristic curve was 0.736.
In a multivariate model, EndoPredict score as a continuous variable was not an independent predictor of response. “The good response was largely driven by covariates that included cell proliferation, and it was Ki-67 that was significant,” Dr. Dubsky noted.
Overall, 18% of the 83 patients in the neoadjuvant endocrine therapy group had a good tumor response (RCB of 0 or I). Here, lower EndoPredict score was associated with greater likelihood of good response. EndoPredict risk group (high vs. low) had a negative predictive value of 92.3%, a positive predictive value of 27.3%, a true-positive rate of 80.0%, and a true-negative rate of 52.9% for predicting response (P = .024). Area under the curve was 0.726.
In a multivariate model here, EndoPredict score as a continuous variable, its estrogen receptor–signaling/differentiation component, and Ki-67 did not independently predict response. “It was maybe a bit surprising that T stage was the strongest factor, possibly indicating that we should have simply treated those women longer than 6 months,” Dr. Dubsky commented. The EndoPredict proliferation component was also a significant predictor.
“Possibly, the very narrow distribution of Ki-67 [among patients given neoendocrine therapy] may have prevented this factor from playing a bigger role in this particular model,” he speculated.
Dr. Dubsky disclosed that he receives consulting fees from Myriad, the maker of EndoPredict, and from Cepheid, Nanostring, and Amgen.
SOURCE: Dubsky P et al. SABCS 2017 Abstract GS6-04.
SAN ANTONIO – The results of the EndoPredict test appear to predict tumor response in patients with early hormone receptor–positive, HER2-negative breast cancer given neoadjuvant therapy, based on results of a study conducted by the Austrian Breast & Colorectal Cancer Study Group (ABCSG).
“Very good tumor shrinkage in estrogen receptor–positive, HER2-negative disease is going to happen only in a minority of patients, and biomarkers that would predict excellent tumor shrinkage are an unmet medical need,” commented lead investigator Peter Dubsky, MD, PhD, who is head of the Breast Center at Hirslanden Klinik St. Anna, Lucerne, Switzerland. “As a surgeon, that would help me to predict breast conservation at diagnosis, but as a surgical oncologist, I would also recognize that tumor response is an important component of future survival.”
The ABCSG findings suggest expanded utility for EndoPredict. The test’s molecular score is currently used along with tumor size and nodal status to predict the 10-year distant recurrence rate, and whether patients may safely forgo chemotherapy or are at high risk and may need adjuvant chemotherapy in addition to endocrine therapy.
Dr. Dubsky and his coinvestigators assessed performance of the EndoPredict test among 217 patients treated on ABCSG 34, a randomized phase 2 neoadjuvant trial. Findings showed that among patients given neoadjuvant endocrine therapy because they had less aggressive disease features, an EndoPredict high-risk result was associated with poor response (negative predictive value of 92%), defined as a residual cancer burden (RCB) of II or III, he reported at the San Antonio Breast Cancer Symposium.
On the other hand, among patients given neoadjuvant chemotherapy because they had more aggressive disease features, a low-risk result was associated with poor response (negative predictive value of 100%).
“Clinicians really gave us two distinct cohorts within ABCSG 34. In the luminal A–type patients who were treated with neoendocrine therapy, a high EndoPredict score predicted a low chance of tumor shrinkage. In the more aggressive ER-positive tumors, so-called luminal B type, treated with neoadjuvant chemotherapy, there was absolutely no excellent response in the low-risk group,” Dr. Dubsky summarized. “We believe that this molecular score may contribute to patient selection for biomarker-driven studies, especially in the neoadjuvant setting.”
Session attendee Steven Vogl, MD, a medical oncologist with the Montefiore Medical Center in New York, commented, “I have trouble correlating an RCB of 0 or I with what you as a surgeon do for the patient, because you are talking about pathologic complete response or just a few cells there. That’s not what determines how much breast you take off: It’s determined by the total size of the tumor and the size of the breast. So if it’s less than a few centimeters, I’m sure you can do a lumpectomy in every patient. Tell me why I should care that you are getting an RCB of 0 or I in these endocrine patients.”
“Because it’s more likely that these patients will have a smaller tumor and better tumor shrinkage,” Dr. Dubsky replied. “You are of course right, RCB 0 or I was not designed to help surgeons. But it helps me as a translational scientist to have a surrogate and an exact classification for good tumor shrinkage. That’s how I used it.”
C. Kent Osborne, MD, codirector of SABCS and director of the Dan L. Duncan Cancer Center at Baylor College of Medicine in Houston, asked, “We see it in the clinic, and I’m sure you have as well, patients whose tumor doesn’t shrink very much, but the Ki-67 really drops. And that may or may not be a better factor than the actual tumor shrinkage. So how many patients who had tumors that didn’t shrink, which was your endpoint, had a reduction in Ki-67 that was, say, 5%?”
“We haven’t looked at that specifically, but we will do so as we carry on with the follow-up of these patients. Then we can learn more about the prognosis,” Dr. Dubsky replied.
Study details
ABCSG 34 was a randomized phase 2 trial testing addition of the cancer vaccine tecemotide (Stimuvax) to neoadjuvant standard of care among patients with HER2-negative early breast cancer.
Dr. Dubsky and coinvestigators restricted analyses to patients with hormone receptor–positive disease who, depending on clinical and pathologic factors, received neoadjuvant chemotherapy (eight cycles of epirubicin-cyclophosphamide and docetaxel) or neoadjuvant endocrine therapy (6 months of letrozole [Femara]) as standard of care. They were then randomized to additionally receive tecemotide or not before undergoing surgery.
Overall, 25% of the 134 patients in the neoadjuvant chemotherapy group had a good tumor response, defined as pathologic complete response in both breast and nodes (RCB of 0) or minimal residual disease (RCB of I).
Higher EndoPredict score was associated with greater likelihood of good response to chemotherapy. EndoPredict risk group (high vs. low) had a negative predictive value of 100%, a positive predictive value of 26.4%, a true-positive rate of 100%, and a true-negative rate of 8.9% for predicting response (P = .112).
Area under the receiver operating characteristic curve was 0.736.
In a multivariate model, EndoPredict score as a continuous variable was not an independent predictor of response. “The good response was largely driven by covariates that included cell proliferation, and it was Ki-67 that was significant,” Dr. Dubsky noted.
Overall, 18% of the 83 patients in the neoadjuvant endocrine therapy group had a good tumor response (RCB of 0 or I). Here, lower EndoPredict score was associated with greater likelihood of good response. EndoPredict risk group (high vs. low) had a negative predictive value of 92.3%, a positive predictive value of 27.3%, a true-positive rate of 80.0%, and a true-negative rate of 52.9% for predicting response (P = .024). Area under the curve was 0.726.
In a multivariate model here, EndoPredict score as a continuous variable, its estrogen receptor–signaling/differentiation component, and Ki-67 did not independently predict response. “It was maybe a bit surprising that T stage was the strongest factor, possibly indicating that we should have simply treated those women longer than 6 months,” Dr. Dubsky commented. The EndoPredict proliferation component was also a significant predictor.
“Possibly, the very narrow distribution of Ki-67 [among patients given neoendocrine therapy] may have prevented this factor from playing a bigger role in this particular model,” he speculated.
Dr. Dubsky disclosed that he receives consulting fees from Myriad, the maker of EndoPredict, and from Cepheid, Nanostring, and Amgen.
SOURCE: Dubsky P et al. SABCS 2017 Abstract GS6-04.
REPORTING FROM SABCS 2017
Key clinical point:
Major finding: EndoPredict predicted poor tumor shrinkage in patients given neoadjuvant endocrine therapy (high-risk test result NPV, 92%) or neoadjuvant chemotherapy (low-risk test result NPV, 100%).
Data source: A cohort study of 217 patients with HR–positive, HER2-negative breast cancer enrolled in a phase 2 trial of neoadjuvant therapy (ABCSG 34).
Disclosures: Dr. Dubsky disclosed that he receives consulting fees from Cepheid, Myriad, Nanostring, and Amgen.
DCIS risk signature is validated in SweDCIS population
SAN ANTONIO – A biological risk signature can help guide decisions about use of adjuvant radiation therapy in patients with ductal carcinoma in situ (DCIS), suggests a validation study reported at the San Antonio Breast Cancer Symposium.
Radiation therapy reduces the 10-year risk of any ipsilateral recurrence in this population by about 50% as established in a large overview of trials (J Natl Cancer Inst Monogr. 2010;2010:162-77), noted lead investigator Fredrik Wärnberg, MD, PhD, of Uppsala Academic Hospital, Uppsala University, Sweden. But factors such as tumor size, grade, and margins have not been helpful in identifying patients most likely to benefit.
He and his colleagues validated a biological risk signature (DCISionRT; PreludeDx) among 584 patients with pure primary DCIS treated on the SweDCIS trial. The trial randomized patients who had undergone breast-conserving surgery to receive radiation therapy or not, and then followed them for 20 years.
The risk signature incorporates four clinicopathologic factors and seven immunohistochemically assessed biomarkers of hormone receptor status, HER2 status, stress response, and proliferation. Possible scores range from 0 to 10, and are split into categories of low risk (0 to 3) and elevated risk (greater than 3). “To me, the magic of this signature is that it is nonlinear. Each factor can be dependent on the value of other factors in the model,” Dr. Wärnberg said.
Results of the validation study showed that among the 506 patients who had clear margins after surgery, radiation therapy significantly reduced the 10-year risk of invasive recurrence in those with an elevated risk score by more than three-fourths, but not in those with a low risk score.
“The biologic risk signature … correlated to risk. It’s prognostic, that’s nothing new,” he summarized. “More interestingly, it was also predictive for radiotherapy benefit. Not all patient groups had the same benefit from radiation therapy. In the low-risk group, there wasn’t any significant benefit from radiation therapy for invasive recurrences. But in the elevated risk group, the radiation therapy benefit was twice as high as expected – about a 76% relative risk reduction with radiotherapy for invasive recurrences.”
Study details
Main results from the SweDCIS trial, previously reported (J Clin Oncol. 2014;32:3613-8), showed that adjuvant radiation therapy reduced recurrences, yielding a 12% absolute reduction in risk of ipsilateral recurrence (10% for in situ recurrences and 2% for invasive recurrences).
For the validation study, Dr. Wärnberg and his colleagues were able to obtain tissue and biological signature results, blinded to patient outcome, for 56% of the original trial population. About half of patients each were determined to have low risk scores and elevated risk scores.
Among the 506 patients with clear margins, the score, analyzed as a continuous variable, was associated with risk of any (in situ or invasive) ipsilateral recurrence during follow-up (hazard ratio, 1.49 per 5-unit increase; P = .038).
In a multivariate model, receipt of radiation therapy was associated with a 52% relative reduction in 10-year risk of any ipsilateral recurrence for those with a low-risk score (HR, 0.48; P = .04) and a greater 69% relative reduction for those with an elevated risk score (HR, 0.31; P less than .001).
Radiation therapy did not significantly reduce the risk of ipsilateral invasive recurrence in the low risk group (HR, 0.84; P = .70), but it did in the elevated risk group (HR, 0.24; P = .012).
These findings essentially mirrored those of a 2015 validation study in a separate cohort of 526 patients from Uppsala University Hospital and the University of Massachusetts, according to Dr. Wärnberg. “We found highly consistent data with these two different sets,” he said.
Analyses additionally showed that radiation therapy reduced the 10-year risk of an invasive breast cancer recurrence by an absolute 1% for patients with low risk scores (not significant) but by an absolute 9% for patients with elevated risk scores (P = .012).
Dr. Wärnberg disclosed that he had no relevant conflicts of interest. The study was funded in part by PreludeDx.
SOURCE: Warnberg et al., SABCS Abstract GS5-08
SAN ANTONIO – A biological risk signature can help guide decisions about use of adjuvant radiation therapy in patients with ductal carcinoma in situ (DCIS), suggests a validation study reported at the San Antonio Breast Cancer Symposium.
Radiation therapy reduces the 10-year risk of any ipsilateral recurrence in this population by about 50% as established in a large overview of trials (J Natl Cancer Inst Monogr. 2010;2010:162-77), noted lead investigator Fredrik Wärnberg, MD, PhD, of Uppsala Academic Hospital, Uppsala University, Sweden. But factors such as tumor size, grade, and margins have not been helpful in identifying patients most likely to benefit.
He and his colleagues validated a biological risk signature (DCISionRT; PreludeDx) among 584 patients with pure primary DCIS treated on the SweDCIS trial. The trial randomized patients who had undergone breast-conserving surgery to receive radiation therapy or not, and then followed them for 20 years.
The risk signature incorporates four clinicopathologic factors and seven immunohistochemically assessed biomarkers of hormone receptor status, HER2 status, stress response, and proliferation. Possible scores range from 0 to 10, and are split into categories of low risk (0 to 3) and elevated risk (greater than 3). “To me, the magic of this signature is that it is nonlinear. Each factor can be dependent on the value of other factors in the model,” Dr. Wärnberg said.
Results of the validation study showed that among the 506 patients who had clear margins after surgery, radiation therapy significantly reduced the 10-year risk of invasive recurrence in those with an elevated risk score by more than three-fourths, but not in those with a low risk score.
“The biologic risk signature … correlated to risk. It’s prognostic, that’s nothing new,” he summarized. “More interestingly, it was also predictive for radiotherapy benefit. Not all patient groups had the same benefit from radiation therapy. In the low-risk group, there wasn’t any significant benefit from radiation therapy for invasive recurrences. But in the elevated risk group, the radiation therapy benefit was twice as high as expected – about a 76% relative risk reduction with radiotherapy for invasive recurrences.”
Study details
Main results from the SweDCIS trial, previously reported (J Clin Oncol. 2014;32:3613-8), showed that adjuvant radiation therapy reduced recurrences, yielding a 12% absolute reduction in risk of ipsilateral recurrence (10% for in situ recurrences and 2% for invasive recurrences).
For the validation study, Dr. Wärnberg and his colleagues were able to obtain tissue and biological signature results, blinded to patient outcome, for 56% of the original trial population. About half of patients each were determined to have low risk scores and elevated risk scores.
Among the 506 patients with clear margins, the score, analyzed as a continuous variable, was associated with risk of any (in situ or invasive) ipsilateral recurrence during follow-up (hazard ratio, 1.49 per 5-unit increase; P = .038).
In a multivariate model, receipt of radiation therapy was associated with a 52% relative reduction in 10-year risk of any ipsilateral recurrence for those with a low-risk score (HR, 0.48; P = .04) and a greater 69% relative reduction for those with an elevated risk score (HR, 0.31; P less than .001).
Radiation therapy did not significantly reduce the risk of ipsilateral invasive recurrence in the low risk group (HR, 0.84; P = .70), but it did in the elevated risk group (HR, 0.24; P = .012).
These findings essentially mirrored those of a 2015 validation study in a separate cohort of 526 patients from Uppsala University Hospital and the University of Massachusetts, according to Dr. Wärnberg. “We found highly consistent data with these two different sets,” he said.
Analyses additionally showed that radiation therapy reduced the 10-year risk of an invasive breast cancer recurrence by an absolute 1% for patients with low risk scores (not significant) but by an absolute 9% for patients with elevated risk scores (P = .012).
Dr. Wärnberg disclosed that he had no relevant conflicts of interest. The study was funded in part by PreludeDx.
SOURCE: Warnberg et al., SABCS Abstract GS5-08
SAN ANTONIO – A biological risk signature can help guide decisions about use of adjuvant radiation therapy in patients with ductal carcinoma in situ (DCIS), suggests a validation study reported at the San Antonio Breast Cancer Symposium.
Radiation therapy reduces the 10-year risk of any ipsilateral recurrence in this population by about 50% as established in a large overview of trials (J Natl Cancer Inst Monogr. 2010;2010:162-77), noted lead investigator Fredrik Wärnberg, MD, PhD, of Uppsala Academic Hospital, Uppsala University, Sweden. But factors such as tumor size, grade, and margins have not been helpful in identifying patients most likely to benefit.
He and his colleagues validated a biological risk signature (DCISionRT; PreludeDx) among 584 patients with pure primary DCIS treated on the SweDCIS trial. The trial randomized patients who had undergone breast-conserving surgery to receive radiation therapy or not, and then followed them for 20 years.
The risk signature incorporates four clinicopathologic factors and seven immunohistochemically assessed biomarkers of hormone receptor status, HER2 status, stress response, and proliferation. Possible scores range from 0 to 10, and are split into categories of low risk (0 to 3) and elevated risk (greater than 3). “To me, the magic of this signature is that it is nonlinear. Each factor can be dependent on the value of other factors in the model,” Dr. Wärnberg said.
Results of the validation study showed that among the 506 patients who had clear margins after surgery, radiation therapy significantly reduced the 10-year risk of invasive recurrence in those with an elevated risk score by more than three-fourths, but not in those with a low risk score.
“The biologic risk signature … correlated to risk. It’s prognostic, that’s nothing new,” he summarized. “More interestingly, it was also predictive for radiotherapy benefit. Not all patient groups had the same benefit from radiation therapy. In the low-risk group, there wasn’t any significant benefit from radiation therapy for invasive recurrences. But in the elevated risk group, the radiation therapy benefit was twice as high as expected – about a 76% relative risk reduction with radiotherapy for invasive recurrences.”
Study details
Main results from the SweDCIS trial, previously reported (J Clin Oncol. 2014;32:3613-8), showed that adjuvant radiation therapy reduced recurrences, yielding a 12% absolute reduction in risk of ipsilateral recurrence (10% for in situ recurrences and 2% for invasive recurrences).
For the validation study, Dr. Wärnberg and his colleagues were able to obtain tissue and biological signature results, blinded to patient outcome, for 56% of the original trial population. About half of patients each were determined to have low risk scores and elevated risk scores.
Among the 506 patients with clear margins, the score, analyzed as a continuous variable, was associated with risk of any (in situ or invasive) ipsilateral recurrence during follow-up (hazard ratio, 1.49 per 5-unit increase; P = .038).
In a multivariate model, receipt of radiation therapy was associated with a 52% relative reduction in 10-year risk of any ipsilateral recurrence for those with a low-risk score (HR, 0.48; P = .04) and a greater 69% relative reduction for those with an elevated risk score (HR, 0.31; P less than .001).
Radiation therapy did not significantly reduce the risk of ipsilateral invasive recurrence in the low risk group (HR, 0.84; P = .70), but it did in the elevated risk group (HR, 0.24; P = .012).
These findings essentially mirrored those of a 2015 validation study in a separate cohort of 526 patients from Uppsala University Hospital and the University of Massachusetts, according to Dr. Wärnberg. “We found highly consistent data with these two different sets,” he said.
Analyses additionally showed that radiation therapy reduced the 10-year risk of an invasive breast cancer recurrence by an absolute 1% for patients with low risk scores (not significant) but by an absolute 9% for patients with elevated risk scores (P = .012).
Dr. Wärnberg disclosed that he had no relevant conflicts of interest. The study was funded in part by PreludeDx.
SOURCE: Warnberg et al., SABCS Abstract GS5-08
REPORTING FROM SABCS 2017
Key clinical point:
Major finding: Among patients with clear margins, radiation therapy significantly reduced 10-year risk of invasive recurrence in those with an elevated risk score (hazard ratio, 0.24; P = .012) but not in those with a low risk score (HR, 0.84; P = .70).
Data source: A validation study in 584 patients with DCIS from a randomized trial of radiation therapy (SweDCIS).
Disclosures: Dr. Wärnberg disclosed that he had no relevant conflicts of interest. The study was funded in part by PreludeDx.
Source: Warnberg et al., SABCS Abstract GS5-08
Postmenopausal women who shed pounds see lower breast cancer risk
SAN ANTONIO – Postmenopausal women may be able to lower their risk of invasive breast cancer by simply losing some weight, according to an analysis of the large prospective Women’s Health Initiative Observational Study.
“While obesity is an established risk factor for postmenopausal breast cancer, studies of weight loss and breast cancer provide inconsistent results. It’s been very, very difficult to show that losing weight changes breast cancer incidence,” said lead investigator Rowan T. Chlebowski, MD, PhD, research professor in the department of medical oncology and therapeutics research at City of Hope in Duarte, Calif. “Consequently, the current public health message is limited to ‘avoid body fatness’ [N Engl J Med. 2016;375:794-8]. That’s not a very strong public health message.”
He and his coinvestigators assessed changes in study participants’ weight during the first 3 years and then ascertained their invasive breast cancer risk after a median follow-up of 11.4 years.
Results showed that compared with peers whose weight remained stable, women who lost at least 5% of their body weight (an average of about 17-20 pounds) had a significant 12% reduction in breast cancer risk, Dr. Chlebowski reported in a session and press briefing at the San Antonio Breast Cancer Symposium. Benefit was similar whether the weight loss was intentional or not, and whether women were normal weight, overweight, or obese at baseline.
“These findings suggest that interventions in postmenopausal women designed to generate weight loss may reduce breast cancer risk. I feel these are very optimistic findings in that they provide a lesson to postmenopausal women that even a moderate degree of weight loss may be associated with health benefits,” he said. “This is a relatively new finding, and I think it should have public health implications.”
Parsing the findings
“I hope that you can present this to general doctors rather than oncologists because those are the ones seeing healthy women, by and large,” said press briefing moderator C. Kent Osborne, MD, codirector of SABCS and director of the Dan L. Duncan Cancer Center at Baylor College of Medicine in Houston. “But in my patients, I’ve always suggested that they lose weight. Most of them with breast cancer are overweight, it seems. And I always had to do it because of diabetes and other factors. Now we can do it because we have a breast cancer endpoint that also suggests that losing weight will help with that as well.”
In discussions among the investigators about implementing the study’s findings via weight loss counseling and intervention, reimbursement was identified as an ongoing concern, Dr. Chlebowski noted. “Certainly, oncologists do not get any money for encouraging this or taking any steps to implement this. So that’s another battle that needs to be conducted.”
Additional results from the study showed that women who experienced a weight gain of at least 5% did not have a significantly elevated risk of breast cancer overall.
“Do you think that the women who gained a little bit of weight didn’t have an increase in incidence because they were already overweight?” Dr. Osborne asked.
“When we go over all these very complex mechanisms and the different drivers, there’s probably a threshold. So obesity’s association with inflammatory factors, I think that’s a driver to a certain degree. But then something else takes over, or maybe the main driver takes over,” Dr. Chlebowski replied. “We don’t have enough data to decide exactly what that threshold is, but that’s the ongoing hypothesis.”
In the session, attendee Daniel McGrail, PhD, of the MD Anderson Cancer Center, Houston, asked, “Since this [risk reduction with weight loss] occurred regardless of initial [body mass index], and you have all these covariates accounted for, does that imply that actually caloric deficits or decreasing caloric intake could be preventing breast cancer risk regardless of initial weight or any other parameters?”
“In all these western diseases, what we take for normal is probably less normal than it might have been 250 years ago or thousands of years ago when we were eating berries and being chased by animals,” Dr. Chlebowski replied. “So this raises a question as to whether the normal weight cutoff should be an ideal weight for western cancer prevention.”
Study details
The Women’s Health Initiative Observational Study recruited 93,676 postmenopausal women aged 50-79 years from 40 U.S. clinical centers during 1993-1998. The women had measurements taken of height and weight at baseline and at year 3 for calculation of BMI, and were asked about intentionality of any weight loss during that period.
Analyses were based on 61,335 women who had normal or higher body weight and were cancer free at baseline, survived at least 3 years, and had adequate data.
Overall, about 13.3% of women lost at least 5% of their body weight between baseline and year 3; 7.9% did so intentionally, losing an average of 19.6 pounds, and 5.5% did so unintentionally, losing an average of 16.9 pounds.
“We used the 5% decrease because this level has been shown to change some biochemical markers potentially associated with cancer. And it has been shown in a different study population, a randomized trial, to reduce the frequency of diabetes,” Dr. Chlebowski noted.
“There was nothing that the study did to induce the weight loss. And based on a partial look at the data, it doesn’t look like many of the women went to some kind of program to lose weight. So it was probably self-directed weight loss,” he noted. “Interestingly, the body mass index of this group was 29.9, so they were on the verge of going into obesity. We wondered in retrospect whether that was a motivating factor for them.”
In multivariate analysis, relative to peers having a stable weight over time, the women losing at least 5% of their weight had a lower risk of breast cancer (hazard ratio, 0.88; 95% confidence interval, 0.78-0.98; P = .02).
Findings were unchanged after further adjustment for mammography frequency. In addition, risk reduction was statistically indistinguishable whether the weight loss was intentional or not (P = .2 for interaction), and whether women were normal weight, overweight, or obese at baseline (P = .4 for interaction).
The 19.6% of women who had a weight gain of at least 5% did not have a significantly elevated risk of breast cancer overall, but they did have a significantly elevated risk of triple-negative breast cancer (HR, 1.54; 95% CI, 1.16-2.05). “We really don’t have a good explanation for this,” Dr. Chlebowski said.
Tackling the global obesity epidemic by conventional means to reduce cancer risk is an uphill battle, he concluded. “We are going to be looking for possible mediating factors. If you can find the mediating factors, pharmacologic intervention would have a much greater chance of success.”
Dr. Chlebowski disclosed that he had no relevant conflicts of interest. Research was supported by the National Heart, Lung and Blood Institute; National Institutes of Health; Department of Health and Human Services; and American Institute for Cancer Research.
SOURCE: Chlebowski et al., SABCS 2017 Abstract GS5-07
SAN ANTONIO – Postmenopausal women may be able to lower their risk of invasive breast cancer by simply losing some weight, according to an analysis of the large prospective Women’s Health Initiative Observational Study.
“While obesity is an established risk factor for postmenopausal breast cancer, studies of weight loss and breast cancer provide inconsistent results. It’s been very, very difficult to show that losing weight changes breast cancer incidence,” said lead investigator Rowan T. Chlebowski, MD, PhD, research professor in the department of medical oncology and therapeutics research at City of Hope in Duarte, Calif. “Consequently, the current public health message is limited to ‘avoid body fatness’ [N Engl J Med. 2016;375:794-8]. That’s not a very strong public health message.”
He and his coinvestigators assessed changes in study participants’ weight during the first 3 years and then ascertained their invasive breast cancer risk after a median follow-up of 11.4 years.
Results showed that compared with peers whose weight remained stable, women who lost at least 5% of their body weight (an average of about 17-20 pounds) had a significant 12% reduction in breast cancer risk, Dr. Chlebowski reported in a session and press briefing at the San Antonio Breast Cancer Symposium. Benefit was similar whether the weight loss was intentional or not, and whether women were normal weight, overweight, or obese at baseline.
“These findings suggest that interventions in postmenopausal women designed to generate weight loss may reduce breast cancer risk. I feel these are very optimistic findings in that they provide a lesson to postmenopausal women that even a moderate degree of weight loss may be associated with health benefits,” he said. “This is a relatively new finding, and I think it should have public health implications.”
Parsing the findings
“I hope that you can present this to general doctors rather than oncologists because those are the ones seeing healthy women, by and large,” said press briefing moderator C. Kent Osborne, MD, codirector of SABCS and director of the Dan L. Duncan Cancer Center at Baylor College of Medicine in Houston. “But in my patients, I’ve always suggested that they lose weight. Most of them with breast cancer are overweight, it seems. And I always had to do it because of diabetes and other factors. Now we can do it because we have a breast cancer endpoint that also suggests that losing weight will help with that as well.”
In discussions among the investigators about implementing the study’s findings via weight loss counseling and intervention, reimbursement was identified as an ongoing concern, Dr. Chlebowski noted. “Certainly, oncologists do not get any money for encouraging this or taking any steps to implement this. So that’s another battle that needs to be conducted.”
Additional results from the study showed that women who experienced a weight gain of at least 5% did not have a significantly elevated risk of breast cancer overall.
“Do you think that the women who gained a little bit of weight didn’t have an increase in incidence because they were already overweight?” Dr. Osborne asked.
“When we go over all these very complex mechanisms and the different drivers, there’s probably a threshold. So obesity’s association with inflammatory factors, I think that’s a driver to a certain degree. But then something else takes over, or maybe the main driver takes over,” Dr. Chlebowski replied. “We don’t have enough data to decide exactly what that threshold is, but that’s the ongoing hypothesis.”
In the session, attendee Daniel McGrail, PhD, of the MD Anderson Cancer Center, Houston, asked, “Since this [risk reduction with weight loss] occurred regardless of initial [body mass index], and you have all these covariates accounted for, does that imply that actually caloric deficits or decreasing caloric intake could be preventing breast cancer risk regardless of initial weight or any other parameters?”
“In all these western diseases, what we take for normal is probably less normal than it might have been 250 years ago or thousands of years ago when we were eating berries and being chased by animals,” Dr. Chlebowski replied. “So this raises a question as to whether the normal weight cutoff should be an ideal weight for western cancer prevention.”
Study details
The Women’s Health Initiative Observational Study recruited 93,676 postmenopausal women aged 50-79 years from 40 U.S. clinical centers during 1993-1998. The women had measurements taken of height and weight at baseline and at year 3 for calculation of BMI, and were asked about intentionality of any weight loss during that period.
Analyses were based on 61,335 women who had normal or higher body weight and were cancer free at baseline, survived at least 3 years, and had adequate data.
Overall, about 13.3% of women lost at least 5% of their body weight between baseline and year 3; 7.9% did so intentionally, losing an average of 19.6 pounds, and 5.5% did so unintentionally, losing an average of 16.9 pounds.
“We used the 5% decrease because this level has been shown to change some biochemical markers potentially associated with cancer. And it has been shown in a different study population, a randomized trial, to reduce the frequency of diabetes,” Dr. Chlebowski noted.
“There was nothing that the study did to induce the weight loss. And based on a partial look at the data, it doesn’t look like many of the women went to some kind of program to lose weight. So it was probably self-directed weight loss,” he noted. “Interestingly, the body mass index of this group was 29.9, so they were on the verge of going into obesity. We wondered in retrospect whether that was a motivating factor for them.”
In multivariate analysis, relative to peers having a stable weight over time, the women losing at least 5% of their weight had a lower risk of breast cancer (hazard ratio, 0.88; 95% confidence interval, 0.78-0.98; P = .02).
Findings were unchanged after further adjustment for mammography frequency. In addition, risk reduction was statistically indistinguishable whether the weight loss was intentional or not (P = .2 for interaction), and whether women were normal weight, overweight, or obese at baseline (P = .4 for interaction).
The 19.6% of women who had a weight gain of at least 5% did not have a significantly elevated risk of breast cancer overall, but they did have a significantly elevated risk of triple-negative breast cancer (HR, 1.54; 95% CI, 1.16-2.05). “We really don’t have a good explanation for this,” Dr. Chlebowski said.
Tackling the global obesity epidemic by conventional means to reduce cancer risk is an uphill battle, he concluded. “We are going to be looking for possible mediating factors. If you can find the mediating factors, pharmacologic intervention would have a much greater chance of success.”
Dr. Chlebowski disclosed that he had no relevant conflicts of interest. Research was supported by the National Heart, Lung and Blood Institute; National Institutes of Health; Department of Health and Human Services; and American Institute for Cancer Research.
SOURCE: Chlebowski et al., SABCS 2017 Abstract GS5-07
SAN ANTONIO – Postmenopausal women may be able to lower their risk of invasive breast cancer by simply losing some weight, according to an analysis of the large prospective Women’s Health Initiative Observational Study.
“While obesity is an established risk factor for postmenopausal breast cancer, studies of weight loss and breast cancer provide inconsistent results. It’s been very, very difficult to show that losing weight changes breast cancer incidence,” said lead investigator Rowan T. Chlebowski, MD, PhD, research professor in the department of medical oncology and therapeutics research at City of Hope in Duarte, Calif. “Consequently, the current public health message is limited to ‘avoid body fatness’ [N Engl J Med. 2016;375:794-8]. That’s not a very strong public health message.”
He and his coinvestigators assessed changes in study participants’ weight during the first 3 years and then ascertained their invasive breast cancer risk after a median follow-up of 11.4 years.
Results showed that compared with peers whose weight remained stable, women who lost at least 5% of their body weight (an average of about 17-20 pounds) had a significant 12% reduction in breast cancer risk, Dr. Chlebowski reported in a session and press briefing at the San Antonio Breast Cancer Symposium. Benefit was similar whether the weight loss was intentional or not, and whether women were normal weight, overweight, or obese at baseline.
“These findings suggest that interventions in postmenopausal women designed to generate weight loss may reduce breast cancer risk. I feel these are very optimistic findings in that they provide a lesson to postmenopausal women that even a moderate degree of weight loss may be associated with health benefits,” he said. “This is a relatively new finding, and I think it should have public health implications.”
Parsing the findings
“I hope that you can present this to general doctors rather than oncologists because those are the ones seeing healthy women, by and large,” said press briefing moderator C. Kent Osborne, MD, codirector of SABCS and director of the Dan L. Duncan Cancer Center at Baylor College of Medicine in Houston. “But in my patients, I’ve always suggested that they lose weight. Most of them with breast cancer are overweight, it seems. And I always had to do it because of diabetes and other factors. Now we can do it because we have a breast cancer endpoint that also suggests that losing weight will help with that as well.”
In discussions among the investigators about implementing the study’s findings via weight loss counseling and intervention, reimbursement was identified as an ongoing concern, Dr. Chlebowski noted. “Certainly, oncologists do not get any money for encouraging this or taking any steps to implement this. So that’s another battle that needs to be conducted.”
Additional results from the study showed that women who experienced a weight gain of at least 5% did not have a significantly elevated risk of breast cancer overall.
“Do you think that the women who gained a little bit of weight didn’t have an increase in incidence because they were already overweight?” Dr. Osborne asked.
“When we go over all these very complex mechanisms and the different drivers, there’s probably a threshold. So obesity’s association with inflammatory factors, I think that’s a driver to a certain degree. But then something else takes over, or maybe the main driver takes over,” Dr. Chlebowski replied. “We don’t have enough data to decide exactly what that threshold is, but that’s the ongoing hypothesis.”
In the session, attendee Daniel McGrail, PhD, of the MD Anderson Cancer Center, Houston, asked, “Since this [risk reduction with weight loss] occurred regardless of initial [body mass index], and you have all these covariates accounted for, does that imply that actually caloric deficits or decreasing caloric intake could be preventing breast cancer risk regardless of initial weight or any other parameters?”
“In all these western diseases, what we take for normal is probably less normal than it might have been 250 years ago or thousands of years ago when we were eating berries and being chased by animals,” Dr. Chlebowski replied. “So this raises a question as to whether the normal weight cutoff should be an ideal weight for western cancer prevention.”
Study details
The Women’s Health Initiative Observational Study recruited 93,676 postmenopausal women aged 50-79 years from 40 U.S. clinical centers during 1993-1998. The women had measurements taken of height and weight at baseline and at year 3 for calculation of BMI, and were asked about intentionality of any weight loss during that period.
Analyses were based on 61,335 women who had normal or higher body weight and were cancer free at baseline, survived at least 3 years, and had adequate data.
Overall, about 13.3% of women lost at least 5% of their body weight between baseline and year 3; 7.9% did so intentionally, losing an average of 19.6 pounds, and 5.5% did so unintentionally, losing an average of 16.9 pounds.
“We used the 5% decrease because this level has been shown to change some biochemical markers potentially associated with cancer. And it has been shown in a different study population, a randomized trial, to reduce the frequency of diabetes,” Dr. Chlebowski noted.
“There was nothing that the study did to induce the weight loss. And based on a partial look at the data, it doesn’t look like many of the women went to some kind of program to lose weight. So it was probably self-directed weight loss,” he noted. “Interestingly, the body mass index of this group was 29.9, so they were on the verge of going into obesity. We wondered in retrospect whether that was a motivating factor for them.”
In multivariate analysis, relative to peers having a stable weight over time, the women losing at least 5% of their weight had a lower risk of breast cancer (hazard ratio, 0.88; 95% confidence interval, 0.78-0.98; P = .02).
Findings were unchanged after further adjustment for mammography frequency. In addition, risk reduction was statistically indistinguishable whether the weight loss was intentional or not (P = .2 for interaction), and whether women were normal weight, overweight, or obese at baseline (P = .4 for interaction).
The 19.6% of women who had a weight gain of at least 5% did not have a significantly elevated risk of breast cancer overall, but they did have a significantly elevated risk of triple-negative breast cancer (HR, 1.54; 95% CI, 1.16-2.05). “We really don’t have a good explanation for this,” Dr. Chlebowski said.
Tackling the global obesity epidemic by conventional means to reduce cancer risk is an uphill battle, he concluded. “We are going to be looking for possible mediating factors. If you can find the mediating factors, pharmacologic intervention would have a much greater chance of success.”
Dr. Chlebowski disclosed that he had no relevant conflicts of interest. Research was supported by the National Heart, Lung and Blood Institute; National Institutes of Health; Department of Health and Human Services; and American Institute for Cancer Research.
SOURCE: Chlebowski et al., SABCS 2017 Abstract GS5-07
REPORTING FROM SABCS 2017
Key clinical point:
Major finding: Compared with peers who had stable weight, women who lost at least 5% of their body weight had a lower risk of invasive breast cancer (hazard ratio, 0.88; P = .02).
Data source: A prospective cohort study of 93,676 postmenopausal women from the Women’s Health Initiative Observational Study.
Disclosures: Dr. Chlebowski disclosed that he had no relevant conflicts of interest. Research was supported by the National Heart, Lung, and Blood Institute; National Institutes of Health; Department of Health and Human Services; and American Institute for Cancer Research.
Source: Chlebowski et al. SABCS 2017 Abstract GS5-07.
PANACEA: pembrolizumab overcomes trastuzumab resistance for some
SAN ANTONIO – The immune checkpoint inhibitor pembrolizumab overcomes trastuzumab resistance in HER2-positive advanced breast cancer provided that the tumor expresses programmed death ligand 1 (PD-L1), a trial reported at the San Antonio Breast Cancer Symposium suggests. But presence of immune cells in the tumor is a major additional determinant of benefit.
“HER2-positive breast cancers have been observed to contain high levels of T-cell infiltration. Tumor-infiltrating lymphocytes (TILs) are associated with improved prognosis and higher response rates to trastuzumab and chemotherapy, suggesting that modulating anti-tumor immunity could further improve survival outcomes,” according to first author Sherene Loi, MD, PhD, an associate professor at Peter MacCallum Cancer Centre in Melbourne, explaining the trial’s rationale. “Trastuzumab itself has been shown to have immune-mediated mechanisms of action, and preclinical studies have suggested that immune-mediated mechanisms of trastuzumab resistance can be overcome with checkpoint inhibition combinations.”
The single-arm phase 1b/2 trial, called PANACEA (also KEYNOTE-014), enrolled 58 patients with HER2-positive advanced breast cancer that had progressed on trastuzumab (Herceptin) or trastuzumab emtansine (Kadcyla). All were given pembrolizumab (Keytruda), which unleashes antitumor immunity by targeting the programmed death-1 receptor on immune cells, in combination with trastuzumab.
With a median follow-up of 13.6 months, the cohort of patients having tumors positive for PD-L1 achieved an overall response rate of 15.2% and a disease control rate of 24%,” Dr. Loi reported in a press briefing and session, on behalf of the International Breast Cancer Study Group and Breast International Group. In contrast, there were no responses in the PD-L1–negative cohort.
Within the PD-L1–positive cohort, stromal levels of TILs in the metastatic lesion – which were low overall – influenced likelihood of benefit. The response rate was almost eight times higher in patients who had at least 5% of the stromal area densely infiltrated with TILs.
“The PANACEA study met its primary endpoint in the PD-L1–positive cohort. For responders, this combination offers durable control without chemotherapy,” Dr. Loi summarized.
“Metastatic HER2-positive breast cancer in this [heavily pretreated] setting is poorly immunogenic, as evidenced by the majority of patients having low TILs in their metastatic lesions. Saying that, however, we did observe a higher response rate in this study as compared to the equivalent triple-negative breast cancer studied in KEYNOTE-086,” she noted. “Future directions in this disease space should focus on combinations with effective anti-HER2 therapy, particularly in low-TIL patients.”
Predicting benefit
The trial is noteworthy for its efforts to identify the subset of patients most likely to benefit from immune checkpoint inhibition, according to press briefing moderator Virginia Kaklamani, MD, a professor of medicine in the division of hematology/oncology at the University of Texas Health Science Center, San Antonio, and a leader of the Breast Cancer Program at the UT Health San Antonio Cancer Center.
“With the triple-negative patient population, we are still struggling to find that subset, and all of the studies that are now being done are looking at all triple-negative breast cancers,” she said. In contrast, “with FISH, we can identify the HER2-positives, and now we are starting to look at PD-L1 expression, we are starting to look at TILs, instead of all the HER2 positive patients.”
In similar studies among patients with HER2-negative breast cancer, PD-L1 did not pan out as a strong predictive biomarker. “What do you think the difference is between that subset and the HER2-positive subset?” Dr. Kaklamani asked.
“First off, I think that there are technical issues with the PD-L1 assay. And we find that patients with high TILs or immune infiltration usually have high levels of PD-L1 expression on their TILs,” Dr. Loi replied. “So I think that PD-L1 can be expressed on the tumor as well as the TIL, and it certainly seems to be the TIL infiltrate that probably enriches for responders to a PD-L1 checkpoint inhibitor on its own or in this case with trastuzumab.”
Study details
In the PANACEA trial (additionally known as IBCSG 45-13 and BIG 4-13), the most common adverse event of any grade and type with the pembrolizumab-trastuzumab combination was fatigue, seen in 21% of patients, Dr. Loi reported. For immune-related adverse events specifically, 19.0% of patients experienced an event, 10.3% experienced an event of grade 3 or worse, and 6.9% stopped treatment because of these events.
“These frequencies are consistent with what has been reported in other solid tumor types with pembrolizumab,” she commented. There were no cardiac events reported.
Efficacy analyses were restricted largely to the PD-L1–positive cohort, given the lack of any response in the negative cohort.
Median duration of response in the positive cohort was 3.5 months, and median duration of disease control was 11.1 months. Five patients (10.8%) remain on treatment with no progression; three of them have completed 2 years of pembrolizumab.
Median progression-free and overall survival were 2.7 and 16.1 months, respectively; corresponding 12-month rates were 13% and 65%. “There is a tantalizing suggestion of a tail on the curve. ... Obviously, this requires further follow-up, and the numbers are small,” Dr. Loi commented.
The median baseline stromal TIL level in metastatic lesions was just 1%. “This is 20 times less than what we observe in primary HER2-positive breast cancers,” she pointed out.
Compared with the PD-L1–negative cohort, the PD-L1–positive cohort had higher TIL levels. Additionally, within that latter cohort, TIL level was higher among patients achieving response versus not (P = .006) and patients achieving disease control versus not (P = .0006).
“We then went on to try to identify a TIL cutoff that could enrich the population for responders. This has been done in other solid tumor types,” Dr. Loi explained.
Analyses in the PD-L1-positive cohort showed that TIL levels down to 5% predicted benefit. The 41% of patients having 5% or more TILs were dramatically more likely to have a response (39% vs. 5%) and disease control (47% vs. 5%).
TIL levels varied widely according to site of the metastasis, with higher levels seen in metastases from lung and lymph nodes, and lower levels seen in those from liver and skin.
“At this stage, we are not sure which is the chicken and the egg: Patients could have disease in their lung and their lymph nodes because their immune system is better controlling their disease,” Dr. Loi commented. “How we treat these patients is still an open question. In patients with liver metastases, perhaps we need to be more aggressive with the primary or tumor-control anti-HER2 therapy.”
Improving efficacy
Going forward, one strategy for improving pembrolizumab efficacy in this patient population might be priming the immune response, according to Dr. Loi.
“In HER2 disease, it’s very clear that oncogenic signaling is the driver, so targeting HER2 potently also will help relieve tumor-mediated immune suppression,” she elaborated. “In this particular context, targeting HER2 well is the key. Whether you need the addition of a little bit of chemo or some radiation, all this needs to be studied.”
Another strategy for improving pembrolizumab efficacy might be moving the drug to earlier disease settings, Dr. Loi proposed.
“By the time you get to advanced stage and have had multiple treatments, you actually have low levels of T-cell infiltration in your metastatic lesion, for whatever reasons – tumor burden, immunosuppression, multiple lines of treatment. That all reduces your chance of responding to pembrolizumab, for example, as monotherapy,” she elaborated. “We don’t know yet if chemotherapy in addition to pembrolizumab could change that tumor microenvironment. But still, I think the earlier in lines you go, the more chance you are going to have of preexisting effective antitumor immunity that can be reactivated with the addition of pembrolizumab.”
Dr. Loi disclosed that her institution receives research funding from Novartis, Pfizer, Merck, Genentech/Roche, and Puma. Merck provided study drug and support for PANACEA.
SOURCE: Loi S et al. SABCS 2017 Abstract GS2-06.
SAN ANTONIO – The immune checkpoint inhibitor pembrolizumab overcomes trastuzumab resistance in HER2-positive advanced breast cancer provided that the tumor expresses programmed death ligand 1 (PD-L1), a trial reported at the San Antonio Breast Cancer Symposium suggests. But presence of immune cells in the tumor is a major additional determinant of benefit.
“HER2-positive breast cancers have been observed to contain high levels of T-cell infiltration. Tumor-infiltrating lymphocytes (TILs) are associated with improved prognosis and higher response rates to trastuzumab and chemotherapy, suggesting that modulating anti-tumor immunity could further improve survival outcomes,” according to first author Sherene Loi, MD, PhD, an associate professor at Peter MacCallum Cancer Centre in Melbourne, explaining the trial’s rationale. “Trastuzumab itself has been shown to have immune-mediated mechanisms of action, and preclinical studies have suggested that immune-mediated mechanisms of trastuzumab resistance can be overcome with checkpoint inhibition combinations.”
The single-arm phase 1b/2 trial, called PANACEA (also KEYNOTE-014), enrolled 58 patients with HER2-positive advanced breast cancer that had progressed on trastuzumab (Herceptin) or trastuzumab emtansine (Kadcyla). All were given pembrolizumab (Keytruda), which unleashes antitumor immunity by targeting the programmed death-1 receptor on immune cells, in combination with trastuzumab.
With a median follow-up of 13.6 months, the cohort of patients having tumors positive for PD-L1 achieved an overall response rate of 15.2% and a disease control rate of 24%,” Dr. Loi reported in a press briefing and session, on behalf of the International Breast Cancer Study Group and Breast International Group. In contrast, there were no responses in the PD-L1–negative cohort.
Within the PD-L1–positive cohort, stromal levels of TILs in the metastatic lesion – which were low overall – influenced likelihood of benefit. The response rate was almost eight times higher in patients who had at least 5% of the stromal area densely infiltrated with TILs.
“The PANACEA study met its primary endpoint in the PD-L1–positive cohort. For responders, this combination offers durable control without chemotherapy,” Dr. Loi summarized.
“Metastatic HER2-positive breast cancer in this [heavily pretreated] setting is poorly immunogenic, as evidenced by the majority of patients having low TILs in their metastatic lesions. Saying that, however, we did observe a higher response rate in this study as compared to the equivalent triple-negative breast cancer studied in KEYNOTE-086,” she noted. “Future directions in this disease space should focus on combinations with effective anti-HER2 therapy, particularly in low-TIL patients.”
Predicting benefit
The trial is noteworthy for its efforts to identify the subset of patients most likely to benefit from immune checkpoint inhibition, according to press briefing moderator Virginia Kaklamani, MD, a professor of medicine in the division of hematology/oncology at the University of Texas Health Science Center, San Antonio, and a leader of the Breast Cancer Program at the UT Health San Antonio Cancer Center.
“With the triple-negative patient population, we are still struggling to find that subset, and all of the studies that are now being done are looking at all triple-negative breast cancers,” she said. In contrast, “with FISH, we can identify the HER2-positives, and now we are starting to look at PD-L1 expression, we are starting to look at TILs, instead of all the HER2 positive patients.”
In similar studies among patients with HER2-negative breast cancer, PD-L1 did not pan out as a strong predictive biomarker. “What do you think the difference is between that subset and the HER2-positive subset?” Dr. Kaklamani asked.
“First off, I think that there are technical issues with the PD-L1 assay. And we find that patients with high TILs or immune infiltration usually have high levels of PD-L1 expression on their TILs,” Dr. Loi replied. “So I think that PD-L1 can be expressed on the tumor as well as the TIL, and it certainly seems to be the TIL infiltrate that probably enriches for responders to a PD-L1 checkpoint inhibitor on its own or in this case with trastuzumab.”
Study details
In the PANACEA trial (additionally known as IBCSG 45-13 and BIG 4-13), the most common adverse event of any grade and type with the pembrolizumab-trastuzumab combination was fatigue, seen in 21% of patients, Dr. Loi reported. For immune-related adverse events specifically, 19.0% of patients experienced an event, 10.3% experienced an event of grade 3 or worse, and 6.9% stopped treatment because of these events.
“These frequencies are consistent with what has been reported in other solid tumor types with pembrolizumab,” she commented. There were no cardiac events reported.
Efficacy analyses were restricted largely to the PD-L1–positive cohort, given the lack of any response in the negative cohort.
Median duration of response in the positive cohort was 3.5 months, and median duration of disease control was 11.1 months. Five patients (10.8%) remain on treatment with no progression; three of them have completed 2 years of pembrolizumab.
Median progression-free and overall survival were 2.7 and 16.1 months, respectively; corresponding 12-month rates were 13% and 65%. “There is a tantalizing suggestion of a tail on the curve. ... Obviously, this requires further follow-up, and the numbers are small,” Dr. Loi commented.
The median baseline stromal TIL level in metastatic lesions was just 1%. “This is 20 times less than what we observe in primary HER2-positive breast cancers,” she pointed out.
Compared with the PD-L1–negative cohort, the PD-L1–positive cohort had higher TIL levels. Additionally, within that latter cohort, TIL level was higher among patients achieving response versus not (P = .006) and patients achieving disease control versus not (P = .0006).
“We then went on to try to identify a TIL cutoff that could enrich the population for responders. This has been done in other solid tumor types,” Dr. Loi explained.
Analyses in the PD-L1-positive cohort showed that TIL levels down to 5% predicted benefit. The 41% of patients having 5% or more TILs were dramatically more likely to have a response (39% vs. 5%) and disease control (47% vs. 5%).
TIL levels varied widely according to site of the metastasis, with higher levels seen in metastases from lung and lymph nodes, and lower levels seen in those from liver and skin.
“At this stage, we are not sure which is the chicken and the egg: Patients could have disease in their lung and their lymph nodes because their immune system is better controlling their disease,” Dr. Loi commented. “How we treat these patients is still an open question. In patients with liver metastases, perhaps we need to be more aggressive with the primary or tumor-control anti-HER2 therapy.”
Improving efficacy
Going forward, one strategy for improving pembrolizumab efficacy in this patient population might be priming the immune response, according to Dr. Loi.
“In HER2 disease, it’s very clear that oncogenic signaling is the driver, so targeting HER2 potently also will help relieve tumor-mediated immune suppression,” she elaborated. “In this particular context, targeting HER2 well is the key. Whether you need the addition of a little bit of chemo or some radiation, all this needs to be studied.”
Another strategy for improving pembrolizumab efficacy might be moving the drug to earlier disease settings, Dr. Loi proposed.
“By the time you get to advanced stage and have had multiple treatments, you actually have low levels of T-cell infiltration in your metastatic lesion, for whatever reasons – tumor burden, immunosuppression, multiple lines of treatment. That all reduces your chance of responding to pembrolizumab, for example, as monotherapy,” she elaborated. “We don’t know yet if chemotherapy in addition to pembrolizumab could change that tumor microenvironment. But still, I think the earlier in lines you go, the more chance you are going to have of preexisting effective antitumor immunity that can be reactivated with the addition of pembrolizumab.”
Dr. Loi disclosed that her institution receives research funding from Novartis, Pfizer, Merck, Genentech/Roche, and Puma. Merck provided study drug and support for PANACEA.
SOURCE: Loi S et al. SABCS 2017 Abstract GS2-06.
SAN ANTONIO – The immune checkpoint inhibitor pembrolizumab overcomes trastuzumab resistance in HER2-positive advanced breast cancer provided that the tumor expresses programmed death ligand 1 (PD-L1), a trial reported at the San Antonio Breast Cancer Symposium suggests. But presence of immune cells in the tumor is a major additional determinant of benefit.
“HER2-positive breast cancers have been observed to contain high levels of T-cell infiltration. Tumor-infiltrating lymphocytes (TILs) are associated with improved prognosis and higher response rates to trastuzumab and chemotherapy, suggesting that modulating anti-tumor immunity could further improve survival outcomes,” according to first author Sherene Loi, MD, PhD, an associate professor at Peter MacCallum Cancer Centre in Melbourne, explaining the trial’s rationale. “Trastuzumab itself has been shown to have immune-mediated mechanisms of action, and preclinical studies have suggested that immune-mediated mechanisms of trastuzumab resistance can be overcome with checkpoint inhibition combinations.”
The single-arm phase 1b/2 trial, called PANACEA (also KEYNOTE-014), enrolled 58 patients with HER2-positive advanced breast cancer that had progressed on trastuzumab (Herceptin) or trastuzumab emtansine (Kadcyla). All were given pembrolizumab (Keytruda), which unleashes antitumor immunity by targeting the programmed death-1 receptor on immune cells, in combination with trastuzumab.
With a median follow-up of 13.6 months, the cohort of patients having tumors positive for PD-L1 achieved an overall response rate of 15.2% and a disease control rate of 24%,” Dr. Loi reported in a press briefing and session, on behalf of the International Breast Cancer Study Group and Breast International Group. In contrast, there were no responses in the PD-L1–negative cohort.
Within the PD-L1–positive cohort, stromal levels of TILs in the metastatic lesion – which were low overall – influenced likelihood of benefit. The response rate was almost eight times higher in patients who had at least 5% of the stromal area densely infiltrated with TILs.
“The PANACEA study met its primary endpoint in the PD-L1–positive cohort. For responders, this combination offers durable control without chemotherapy,” Dr. Loi summarized.
“Metastatic HER2-positive breast cancer in this [heavily pretreated] setting is poorly immunogenic, as evidenced by the majority of patients having low TILs in their metastatic lesions. Saying that, however, we did observe a higher response rate in this study as compared to the equivalent triple-negative breast cancer studied in KEYNOTE-086,” she noted. “Future directions in this disease space should focus on combinations with effective anti-HER2 therapy, particularly in low-TIL patients.”
Predicting benefit
The trial is noteworthy for its efforts to identify the subset of patients most likely to benefit from immune checkpoint inhibition, according to press briefing moderator Virginia Kaklamani, MD, a professor of medicine in the division of hematology/oncology at the University of Texas Health Science Center, San Antonio, and a leader of the Breast Cancer Program at the UT Health San Antonio Cancer Center.
“With the triple-negative patient population, we are still struggling to find that subset, and all of the studies that are now being done are looking at all triple-negative breast cancers,” she said. In contrast, “with FISH, we can identify the HER2-positives, and now we are starting to look at PD-L1 expression, we are starting to look at TILs, instead of all the HER2 positive patients.”
In similar studies among patients with HER2-negative breast cancer, PD-L1 did not pan out as a strong predictive biomarker. “What do you think the difference is between that subset and the HER2-positive subset?” Dr. Kaklamani asked.
“First off, I think that there are technical issues with the PD-L1 assay. And we find that patients with high TILs or immune infiltration usually have high levels of PD-L1 expression on their TILs,” Dr. Loi replied. “So I think that PD-L1 can be expressed on the tumor as well as the TIL, and it certainly seems to be the TIL infiltrate that probably enriches for responders to a PD-L1 checkpoint inhibitor on its own or in this case with trastuzumab.”
Study details
In the PANACEA trial (additionally known as IBCSG 45-13 and BIG 4-13), the most common adverse event of any grade and type with the pembrolizumab-trastuzumab combination was fatigue, seen in 21% of patients, Dr. Loi reported. For immune-related adverse events specifically, 19.0% of patients experienced an event, 10.3% experienced an event of grade 3 or worse, and 6.9% stopped treatment because of these events.
“These frequencies are consistent with what has been reported in other solid tumor types with pembrolizumab,” she commented. There were no cardiac events reported.
Efficacy analyses were restricted largely to the PD-L1–positive cohort, given the lack of any response in the negative cohort.
Median duration of response in the positive cohort was 3.5 months, and median duration of disease control was 11.1 months. Five patients (10.8%) remain on treatment with no progression; three of them have completed 2 years of pembrolizumab.
Median progression-free and overall survival were 2.7 and 16.1 months, respectively; corresponding 12-month rates were 13% and 65%. “There is a tantalizing suggestion of a tail on the curve. ... Obviously, this requires further follow-up, and the numbers are small,” Dr. Loi commented.
The median baseline stromal TIL level in metastatic lesions was just 1%. “This is 20 times less than what we observe in primary HER2-positive breast cancers,” she pointed out.
Compared with the PD-L1–negative cohort, the PD-L1–positive cohort had higher TIL levels. Additionally, within that latter cohort, TIL level was higher among patients achieving response versus not (P = .006) and patients achieving disease control versus not (P = .0006).
“We then went on to try to identify a TIL cutoff that could enrich the population for responders. This has been done in other solid tumor types,” Dr. Loi explained.
Analyses in the PD-L1-positive cohort showed that TIL levels down to 5% predicted benefit. The 41% of patients having 5% or more TILs were dramatically more likely to have a response (39% vs. 5%) and disease control (47% vs. 5%).
TIL levels varied widely according to site of the metastasis, with higher levels seen in metastases from lung and lymph nodes, and lower levels seen in those from liver and skin.
“At this stage, we are not sure which is the chicken and the egg: Patients could have disease in their lung and their lymph nodes because their immune system is better controlling their disease,” Dr. Loi commented. “How we treat these patients is still an open question. In patients with liver metastases, perhaps we need to be more aggressive with the primary or tumor-control anti-HER2 therapy.”
Improving efficacy
Going forward, one strategy for improving pembrolizumab efficacy in this patient population might be priming the immune response, according to Dr. Loi.
“In HER2 disease, it’s very clear that oncogenic signaling is the driver, so targeting HER2 potently also will help relieve tumor-mediated immune suppression,” she elaborated. “In this particular context, targeting HER2 well is the key. Whether you need the addition of a little bit of chemo or some radiation, all this needs to be studied.”
Another strategy for improving pembrolizumab efficacy might be moving the drug to earlier disease settings, Dr. Loi proposed.
“By the time you get to advanced stage and have had multiple treatments, you actually have low levels of T-cell infiltration in your metastatic lesion, for whatever reasons – tumor burden, immunosuppression, multiple lines of treatment. That all reduces your chance of responding to pembrolizumab, for example, as monotherapy,” she elaborated. “We don’t know yet if chemotherapy in addition to pembrolizumab could change that tumor microenvironment. But still, I think the earlier in lines you go, the more chance you are going to have of preexisting effective antitumor immunity that can be reactivated with the addition of pembrolizumab.”
Dr. Loi disclosed that her institution receives research funding from Novartis, Pfizer, Merck, Genentech/Roche, and Puma. Merck provided study drug and support for PANACEA.
SOURCE: Loi S et al. SABCS 2017 Abstract GS2-06.
REPORTING FROM SABCS 2017
Key clinical point:
Major finding: The PD-L1–positive cohort had an overall response rate of 15.2% and a disease control rate of 24%.
Data source: A single-arm phase 1b/2 trial among 58 women with trastuzumab-resistant HER2-positive advanced breast cancer (PANACEA study).
Disclosures: Dr. Loi disclosed that her institution receives research funding from Novartis, Pfizer, Merck, Genentech/Roche, and Puma. Merck provided study drug and support.
Source: Loi S et al. SABCS 2017 Abstract GS2-06.
Ovarian suppression during breast cancer chemo helps stave off early menopause, preserve fertility
SAN ANTONIO – Premenopausal women with early breast cancer should be offered temporary ovarian suppression during chemotherapy if they wish to remain fertile or avoid early menopause, suggests a meta-analysis of five randomized controlled trials among 873 women reported at the San Antonio Breast Cancer Symposium.
“Oocyte and embryo cryopreservation are standard strategies for fertility preservation in these patients, meaning increasing the chance of pregnancy after the end of treatment,” said lead author Matteo Lambertini, MD, medical oncologist and ESMO fellow at the Institut Jules Bordet in Brussels. “However, they do not prevent the risk of developing chemotherapy-induced premature ovarian insufficiency, and so patients are still at risk of developing early menopause.”
Data from individual trials of ovarian suppression have been mixed, and its use remains controversial, he further noted. As a result, guidelines from ASCO and ESMO for fertility preservation in cancer patients still consider ovarian suppression to be investigational.
Results of the new meta-analysis, reported in a press briefing and session, showed that, compared with control peers, premenopausal women given a gonadotropin-releasing hormone analog (GnRHa) to suppress ovarian function during breast cancer chemotherapy had a more than one-half reduction in odds of premature ovarian insufficiency and were almost twice as likely to become pregnant after completing their treatment.
“We believe that this strategy should now be considered a standard option to reduce the likelihood of chemotherapy-induced premature ovarian insufficiency and potentially improve future fertility in premenopausal early breast cancer patients who undergo adjuvant or neoadjuvant chemotherapy,” Dr. Lambertini maintained. The analysis and trial participants “remind us that there is a life after cancer and to cure the disease should not be considered enough any more.”
These new data are sufficient to put the controversy to rest, for several reasons, he contended. “First, this is an individual-patient meta-analysis of the five major randomized controlled trials in this setting, so it’s kind of the highest level of evidence that we can reach. Second, it’s very unlikely that we will have new randomized, controlled trials in this setting, and I would say also that, based on the results, it would probably be unethical to run randomized, controlled trials in this setting.”
Press briefing moderator Carlos L. Arteaga, MD, director of the Harold C. Simmons Comprehensive Cancer Center at UT Southwestern Medical Center, Dallas, wondered how trials were selected for inclusion in the meta-analysis.
Thirteen trials have been conducted on ovarian suppression in premenopausal patients with breast cancer, and the investigators included the five for which they were able to obtain patient-level data, a subset that contained both positive and negative trials, Dr. Lambertini replied. But findings would likely be the same had all trials been included, given that a 2015 analysis using trial-level data from the 12 trials completed at that time showed very similar results (Ann Oncol. 2015 Dec;26:2408-19).
“Societally, this is a hugely significant issue, but the difference you are showing I have to admit is rather modest,” commented Dr. Arteaga, who is also SABCS codirector and AACR past president. “So what kind of conversation do you have with the patient? Who are the ones who would be the best candidates for this approach?”
“The main message is that giving a GnRHa does not avoid the risk of early menopause in all patients, but still, it decreases significantly the number of patients who have this side effect,” Dr. Lambertini replied.
Two groups are optimal candidates for ovarian suppression, he proposed. “First, the patients who are concerned about developing early menopause and its related side effects, who are not interested per se in having a baby after the end of treatment, but may be preserving ovarian function. [Second], for patients interested in having a baby, so interested in fertility preservation, this strategy can be used after cryopreservation procedures or in patients who have no access, for different reasons, to cryopreservation strategies.”
Another point of view
In the session, attendee Kutluk Oktay, MD, PhD, professor of obstetrics & gynecology and reproductive sciences at Yale University, New Haven, and cochair of ASCO’s guideline committee on fertility preservation said, “I cannot agree with your conclusions based on what you presented to us.”
In particular, he took issue with the exclusion of additional trials in breast cancer as well as trials among patients with other types of cancers. “I’m wondering what the rationale is to limit this to breast cancer because chemotherapy is chemotherapy and ovary is ovary, so underlying disease should not matter. By limiting it to breast cancer, you are leaving out three important studies, all in hematological cancer, with better designs … three negative studies,” he commented.
From a clinical point of view, patients with lymphoma and patients with breast cancer differ greatly, Dr. Lambertini countered: The former are about 20 years younger, on average, and often receive less-granulotoxic chemotherapy. “For these reasons, I don’t believe that mixing these two populations would have been [appropriate] for analysis,” he said. “From a methodological point of view, the studies you have mentioned include overall [fewer] than 150 patients, so it’s a very small proportion in comparison to the data we have in breast cancer.”
Study details
For their meta-analysis, Dr. Lambertini and coinvestigators pooled individual patient data from five trials (PROMISE-GIM6, POEMS/SWOG S0230, Anglo-Celtic Group OPTION, GBG-37 ZORO, and a trial led by the Moffitt Cancer Center) that randomized premenopausal women with early breast cancer to adjuvant or neoadjuvant chemotherapy either with or without concurrent GnRHa therapy.
Two of the trials restricted enrollment to women with estrogen receptor (ER)-negative disease. The GnRHa agents used were triptorelin (Trelstar, Triptodur)and goserelin(Zoladex).
Main results showed that the rate of premature ovarian insufficiency, defined differently across trials, was 14.1% among women given a GnRHa and 30.9% among control women (adjusted odds ratio, 0.38; P less than .001), Dr. Lambertini reported. Findings were similar in subgroups stratified by age, ER status, and type and duration of chemotherapy.
The rate of amenorrhea, used as a standardized definition of premature ovarian insufficiency, was similar in the GnRHa and control groups at 1 year (36.8% and 40.4%) but sharply lower in the former at 2 years (18.2% vs. 30.0%; adjusted odds ratio, 0.51; P = .009).
Overall, 10.3% of women in the GnRHa group and 5.5% in the control group had at least one pregnancy after completing their breast cancer treatment (incidence rate ratio, 1.83; P = .030). “All of the randomized trials except for the POEMS study actually did not have fertility outcomes as a preplanned endpoint, and so the patients’ wish to have a pregnancy was not collected,” he noted; therefore, it was not possible to calculate pregnancy rates in the subset who actually wanted to conceive.
All pregnancies occurred among women aged 40 years or younger, and 86% occurred among women who had had ER-negative disease, likely reflecting use of adjuvant endocrine therapy in patients with ER-positive disease, he said. Of the 57 total pregnancies, 50 resulted in live births, and none of the infants had malformations; the other pregnancies ended in spontaneous or induced abortion.
With a median follow-up of 5 years, the groups did not differ significantly on rates of disease-free survival and overall survival, suggesting that ovarian suppression was safe, according to Dr. Lambertini. Findings were similar when patients were stratified by ER status.
“What I think researchers should do in the next year is to better understand how this strategy [of ovarian suppression] works because this is probably the main controversy right now, because it’s still not very clear how this strategy actually works,” he concluded.
SOURCE: Lambertini M et al., SABCS 2017 Abstract GS4-01.
SAN ANTONIO – Premenopausal women with early breast cancer should be offered temporary ovarian suppression during chemotherapy if they wish to remain fertile or avoid early menopause, suggests a meta-analysis of five randomized controlled trials among 873 women reported at the San Antonio Breast Cancer Symposium.
“Oocyte and embryo cryopreservation are standard strategies for fertility preservation in these patients, meaning increasing the chance of pregnancy after the end of treatment,” said lead author Matteo Lambertini, MD, medical oncologist and ESMO fellow at the Institut Jules Bordet in Brussels. “However, they do not prevent the risk of developing chemotherapy-induced premature ovarian insufficiency, and so patients are still at risk of developing early menopause.”
Data from individual trials of ovarian suppression have been mixed, and its use remains controversial, he further noted. As a result, guidelines from ASCO and ESMO for fertility preservation in cancer patients still consider ovarian suppression to be investigational.
Results of the new meta-analysis, reported in a press briefing and session, showed that, compared with control peers, premenopausal women given a gonadotropin-releasing hormone analog (GnRHa) to suppress ovarian function during breast cancer chemotherapy had a more than one-half reduction in odds of premature ovarian insufficiency and were almost twice as likely to become pregnant after completing their treatment.
“We believe that this strategy should now be considered a standard option to reduce the likelihood of chemotherapy-induced premature ovarian insufficiency and potentially improve future fertility in premenopausal early breast cancer patients who undergo adjuvant or neoadjuvant chemotherapy,” Dr. Lambertini maintained. The analysis and trial participants “remind us that there is a life after cancer and to cure the disease should not be considered enough any more.”
These new data are sufficient to put the controversy to rest, for several reasons, he contended. “First, this is an individual-patient meta-analysis of the five major randomized controlled trials in this setting, so it’s kind of the highest level of evidence that we can reach. Second, it’s very unlikely that we will have new randomized, controlled trials in this setting, and I would say also that, based on the results, it would probably be unethical to run randomized, controlled trials in this setting.”
Press briefing moderator Carlos L. Arteaga, MD, director of the Harold C. Simmons Comprehensive Cancer Center at UT Southwestern Medical Center, Dallas, wondered how trials were selected for inclusion in the meta-analysis.
Thirteen trials have been conducted on ovarian suppression in premenopausal patients with breast cancer, and the investigators included the five for which they were able to obtain patient-level data, a subset that contained both positive and negative trials, Dr. Lambertini replied. But findings would likely be the same had all trials been included, given that a 2015 analysis using trial-level data from the 12 trials completed at that time showed very similar results (Ann Oncol. 2015 Dec;26:2408-19).
“Societally, this is a hugely significant issue, but the difference you are showing I have to admit is rather modest,” commented Dr. Arteaga, who is also SABCS codirector and AACR past president. “So what kind of conversation do you have with the patient? Who are the ones who would be the best candidates for this approach?”
“The main message is that giving a GnRHa does not avoid the risk of early menopause in all patients, but still, it decreases significantly the number of patients who have this side effect,” Dr. Lambertini replied.
Two groups are optimal candidates for ovarian suppression, he proposed. “First, the patients who are concerned about developing early menopause and its related side effects, who are not interested per se in having a baby after the end of treatment, but may be preserving ovarian function. [Second], for patients interested in having a baby, so interested in fertility preservation, this strategy can be used after cryopreservation procedures or in patients who have no access, for different reasons, to cryopreservation strategies.”
Another point of view
In the session, attendee Kutluk Oktay, MD, PhD, professor of obstetrics & gynecology and reproductive sciences at Yale University, New Haven, and cochair of ASCO’s guideline committee on fertility preservation said, “I cannot agree with your conclusions based on what you presented to us.”
In particular, he took issue with the exclusion of additional trials in breast cancer as well as trials among patients with other types of cancers. “I’m wondering what the rationale is to limit this to breast cancer because chemotherapy is chemotherapy and ovary is ovary, so underlying disease should not matter. By limiting it to breast cancer, you are leaving out three important studies, all in hematological cancer, with better designs … three negative studies,” he commented.
From a clinical point of view, patients with lymphoma and patients with breast cancer differ greatly, Dr. Lambertini countered: The former are about 20 years younger, on average, and often receive less-granulotoxic chemotherapy. “For these reasons, I don’t believe that mixing these two populations would have been [appropriate] for analysis,” he said. “From a methodological point of view, the studies you have mentioned include overall [fewer] than 150 patients, so it’s a very small proportion in comparison to the data we have in breast cancer.”
Study details
For their meta-analysis, Dr. Lambertini and coinvestigators pooled individual patient data from five trials (PROMISE-GIM6, POEMS/SWOG S0230, Anglo-Celtic Group OPTION, GBG-37 ZORO, and a trial led by the Moffitt Cancer Center) that randomized premenopausal women with early breast cancer to adjuvant or neoadjuvant chemotherapy either with or without concurrent GnRHa therapy.
Two of the trials restricted enrollment to women with estrogen receptor (ER)-negative disease. The GnRHa agents used were triptorelin (Trelstar, Triptodur)and goserelin(Zoladex).
Main results showed that the rate of premature ovarian insufficiency, defined differently across trials, was 14.1% among women given a GnRHa and 30.9% among control women (adjusted odds ratio, 0.38; P less than .001), Dr. Lambertini reported. Findings were similar in subgroups stratified by age, ER status, and type and duration of chemotherapy.
The rate of amenorrhea, used as a standardized definition of premature ovarian insufficiency, was similar in the GnRHa and control groups at 1 year (36.8% and 40.4%) but sharply lower in the former at 2 years (18.2% vs. 30.0%; adjusted odds ratio, 0.51; P = .009).
Overall, 10.3% of women in the GnRHa group and 5.5% in the control group had at least one pregnancy after completing their breast cancer treatment (incidence rate ratio, 1.83; P = .030). “All of the randomized trials except for the POEMS study actually did not have fertility outcomes as a preplanned endpoint, and so the patients’ wish to have a pregnancy was not collected,” he noted; therefore, it was not possible to calculate pregnancy rates in the subset who actually wanted to conceive.
All pregnancies occurred among women aged 40 years or younger, and 86% occurred among women who had had ER-negative disease, likely reflecting use of adjuvant endocrine therapy in patients with ER-positive disease, he said. Of the 57 total pregnancies, 50 resulted in live births, and none of the infants had malformations; the other pregnancies ended in spontaneous or induced abortion.
With a median follow-up of 5 years, the groups did not differ significantly on rates of disease-free survival and overall survival, suggesting that ovarian suppression was safe, according to Dr. Lambertini. Findings were similar when patients were stratified by ER status.
“What I think researchers should do in the next year is to better understand how this strategy [of ovarian suppression] works because this is probably the main controversy right now, because it’s still not very clear how this strategy actually works,” he concluded.
SOURCE: Lambertini M et al., SABCS 2017 Abstract GS4-01.
SAN ANTONIO – Premenopausal women with early breast cancer should be offered temporary ovarian suppression during chemotherapy if they wish to remain fertile or avoid early menopause, suggests a meta-analysis of five randomized controlled trials among 873 women reported at the San Antonio Breast Cancer Symposium.
“Oocyte and embryo cryopreservation are standard strategies for fertility preservation in these patients, meaning increasing the chance of pregnancy after the end of treatment,” said lead author Matteo Lambertini, MD, medical oncologist and ESMO fellow at the Institut Jules Bordet in Brussels. “However, they do not prevent the risk of developing chemotherapy-induced premature ovarian insufficiency, and so patients are still at risk of developing early menopause.”
Data from individual trials of ovarian suppression have been mixed, and its use remains controversial, he further noted. As a result, guidelines from ASCO and ESMO for fertility preservation in cancer patients still consider ovarian suppression to be investigational.
Results of the new meta-analysis, reported in a press briefing and session, showed that, compared with control peers, premenopausal women given a gonadotropin-releasing hormone analog (GnRHa) to suppress ovarian function during breast cancer chemotherapy had a more than one-half reduction in odds of premature ovarian insufficiency and were almost twice as likely to become pregnant after completing their treatment.
“We believe that this strategy should now be considered a standard option to reduce the likelihood of chemotherapy-induced premature ovarian insufficiency and potentially improve future fertility in premenopausal early breast cancer patients who undergo adjuvant or neoadjuvant chemotherapy,” Dr. Lambertini maintained. The analysis and trial participants “remind us that there is a life after cancer and to cure the disease should not be considered enough any more.”
These new data are sufficient to put the controversy to rest, for several reasons, he contended. “First, this is an individual-patient meta-analysis of the five major randomized controlled trials in this setting, so it’s kind of the highest level of evidence that we can reach. Second, it’s very unlikely that we will have new randomized, controlled trials in this setting, and I would say also that, based on the results, it would probably be unethical to run randomized, controlled trials in this setting.”
Press briefing moderator Carlos L. Arteaga, MD, director of the Harold C. Simmons Comprehensive Cancer Center at UT Southwestern Medical Center, Dallas, wondered how trials were selected for inclusion in the meta-analysis.
Thirteen trials have been conducted on ovarian suppression in premenopausal patients with breast cancer, and the investigators included the five for which they were able to obtain patient-level data, a subset that contained both positive and negative trials, Dr. Lambertini replied. But findings would likely be the same had all trials been included, given that a 2015 analysis using trial-level data from the 12 trials completed at that time showed very similar results (Ann Oncol. 2015 Dec;26:2408-19).
“Societally, this is a hugely significant issue, but the difference you are showing I have to admit is rather modest,” commented Dr. Arteaga, who is also SABCS codirector and AACR past president. “So what kind of conversation do you have with the patient? Who are the ones who would be the best candidates for this approach?”
“The main message is that giving a GnRHa does not avoid the risk of early menopause in all patients, but still, it decreases significantly the number of patients who have this side effect,” Dr. Lambertini replied.
Two groups are optimal candidates for ovarian suppression, he proposed. “First, the patients who are concerned about developing early menopause and its related side effects, who are not interested per se in having a baby after the end of treatment, but may be preserving ovarian function. [Second], for patients interested in having a baby, so interested in fertility preservation, this strategy can be used after cryopreservation procedures or in patients who have no access, for different reasons, to cryopreservation strategies.”
Another point of view
In the session, attendee Kutluk Oktay, MD, PhD, professor of obstetrics & gynecology and reproductive sciences at Yale University, New Haven, and cochair of ASCO’s guideline committee on fertility preservation said, “I cannot agree with your conclusions based on what you presented to us.”
In particular, he took issue with the exclusion of additional trials in breast cancer as well as trials among patients with other types of cancers. “I’m wondering what the rationale is to limit this to breast cancer because chemotherapy is chemotherapy and ovary is ovary, so underlying disease should not matter. By limiting it to breast cancer, you are leaving out three important studies, all in hematological cancer, with better designs … three negative studies,” he commented.
From a clinical point of view, patients with lymphoma and patients with breast cancer differ greatly, Dr. Lambertini countered: The former are about 20 years younger, on average, and often receive less-granulotoxic chemotherapy. “For these reasons, I don’t believe that mixing these two populations would have been [appropriate] for analysis,” he said. “From a methodological point of view, the studies you have mentioned include overall [fewer] than 150 patients, so it’s a very small proportion in comparison to the data we have in breast cancer.”
Study details
For their meta-analysis, Dr. Lambertini and coinvestigators pooled individual patient data from five trials (PROMISE-GIM6, POEMS/SWOG S0230, Anglo-Celtic Group OPTION, GBG-37 ZORO, and a trial led by the Moffitt Cancer Center) that randomized premenopausal women with early breast cancer to adjuvant or neoadjuvant chemotherapy either with or without concurrent GnRHa therapy.
Two of the trials restricted enrollment to women with estrogen receptor (ER)-negative disease. The GnRHa agents used were triptorelin (Trelstar, Triptodur)and goserelin(Zoladex).
Main results showed that the rate of premature ovarian insufficiency, defined differently across trials, was 14.1% among women given a GnRHa and 30.9% among control women (adjusted odds ratio, 0.38; P less than .001), Dr. Lambertini reported. Findings were similar in subgroups stratified by age, ER status, and type and duration of chemotherapy.
The rate of amenorrhea, used as a standardized definition of premature ovarian insufficiency, was similar in the GnRHa and control groups at 1 year (36.8% and 40.4%) but sharply lower in the former at 2 years (18.2% vs. 30.0%; adjusted odds ratio, 0.51; P = .009).
Overall, 10.3% of women in the GnRHa group and 5.5% in the control group had at least one pregnancy after completing their breast cancer treatment (incidence rate ratio, 1.83; P = .030). “All of the randomized trials except for the POEMS study actually did not have fertility outcomes as a preplanned endpoint, and so the patients’ wish to have a pregnancy was not collected,” he noted; therefore, it was not possible to calculate pregnancy rates in the subset who actually wanted to conceive.
All pregnancies occurred among women aged 40 years or younger, and 86% occurred among women who had had ER-negative disease, likely reflecting use of adjuvant endocrine therapy in patients with ER-positive disease, he said. Of the 57 total pregnancies, 50 resulted in live births, and none of the infants had malformations; the other pregnancies ended in spontaneous or induced abortion.
With a median follow-up of 5 years, the groups did not differ significantly on rates of disease-free survival and overall survival, suggesting that ovarian suppression was safe, according to Dr. Lambertini. Findings were similar when patients were stratified by ER status.
“What I think researchers should do in the next year is to better understand how this strategy [of ovarian suppression] works because this is probably the main controversy right now, because it’s still not very clear how this strategy actually works,” he concluded.
SOURCE: Lambertini M et al., SABCS 2017 Abstract GS4-01.
REPORTING FROM SABCS 2017
Key clinical point:
Major finding: Compared with controls, women given a GnRHa during chemotherapy were less likely to develop premature ovarian insufficiency (adjusted OR, 0.38; P less than .001) and more likely to become pregnant after treatment (IRR, 1.83; P = .030).
Data source: A meta-analysis of individual patient data from five trials among 873 premenopausal women with early breast cancer.
Disclosures: Dr. Lambertini disclosed that he had no relevant conflicts of interest.
Source: Lambertini M et al., SABCS 2017 Abstract GS4-01.
VIDEO: Weight loss cut risk of breast cancer
SAN ANTONIO – A new analysis from the Women’s Health Initiative Observational Study gives postmenopausal women yet another reason to mind their weight. Results showed that women losing at least 5% of their body weight had a significant 12% reduction in adjusted breast cancer risk relative to peers who maintained a stable weight, reported lead author Rowan Chlebowski, MD, PhD, research professor in the department of medical oncology and therapeutics research at City of Hope in Duarte, Calif. Findings were much the same regardless of whether women were of normal weight, overweight, or obese at baseline. Dr. Chlebowski discussed the implications for patient counseling and insurance coverage of weight loss interventions, as well as planned research that will assess the physiologic mechanisms at play in a video interview.
SAN ANTONIO – A new analysis from the Women’s Health Initiative Observational Study gives postmenopausal women yet another reason to mind their weight. Results showed that women losing at least 5% of their body weight had a significant 12% reduction in adjusted breast cancer risk relative to peers who maintained a stable weight, reported lead author Rowan Chlebowski, MD, PhD, research professor in the department of medical oncology and therapeutics research at City of Hope in Duarte, Calif. Findings were much the same regardless of whether women were of normal weight, overweight, or obese at baseline. Dr. Chlebowski discussed the implications for patient counseling and insurance coverage of weight loss interventions, as well as planned research that will assess the physiologic mechanisms at play in a video interview.
SAN ANTONIO – A new analysis from the Women’s Health Initiative Observational Study gives postmenopausal women yet another reason to mind their weight. Results showed that women losing at least 5% of their body weight had a significant 12% reduction in adjusted breast cancer risk relative to peers who maintained a stable weight, reported lead author Rowan Chlebowski, MD, PhD, research professor in the department of medical oncology and therapeutics research at City of Hope in Duarte, Calif. Findings were much the same regardless of whether women were of normal weight, overweight, or obese at baseline. Dr. Chlebowski discussed the implications for patient counseling and insurance coverage of weight loss interventions, as well as planned research that will assess the physiologic mechanisms at play in a video interview.
REPORTING FROM SABCS 2017
Dose intensification gets more mileage out of adjuvant chemo
SAN ANTONIO – Increasing the dose intensity of adjuvant chemotherapy for breast cancer by spacing cycles more closely or by giving drugs sequentially instead of concurrently improves outcomes, confirms a meta-analysis conducted by the Early Breast Cancer Trialists’ Collaborative Group (EBCTCG).
Investigators led by Richard Gray, MSc, a professor of medical statistics in the Nuffield Department of Population Health at the University of Oxford in Oxford, England, analyzed individual patient data from 25 randomized trials among 34,122 women with early-stage breast cancer.
Results showed that depending on which specific strategy was used, women were 13%-18% less likely to experience recurrence and 11%-18% less likely to die from breast cancer if they were given dose-intensified chemotherapy instead of standard chemotherapy, he reported in a press briefing and a session at the San Antonio Breast Cancer Symposium.
“Shortening the interval between cycles and sequential administration of anthracycline and taxane chemotherapy reduces both recurrence and death from breast cancer,” Mr. Gray summarized. “The reductions are about 15%. They were seen in both estrogen receptor [ER]–positive and ER-negative disease and did not differ significantly by any other tumor or patient characteristics.”
“The beauty of this is these are the exact same drugs and, in many cases, similar doses. It’s just the schedule that changes,” commented press briefing moderator Virginia Kaklamani, MD, a professor of medicine in the division of hematology/oncology at the University of Texas Health Science Center San Antonio and a leader of the Breast Cancer Program at the UT Health San Antonio Cancer Center. “We used to give chemotherapy over 6 months, and with this approach, we can give it over 4 months, so the patients prefer it. The toxicity, with the growth factors for support, can be less. So everybody wins here.”
“Most of us [U.S. oncologists] have been using these [dose-intensification] approaches for the past several years because of a couple pivotal trials. But the benefits from those pivotal trials were not as impressive by themselves,” she added. The meta-analysis shows that “when you give chemotherapy in the right way, you almost double the benefit. So this is huge, even in the era of having immunotherapeutic drugs and all these other targeted drugs. The main treatment I offer my patients every single day is still chemotherapy, and I’d rather make it better and better tolerated.”
Study details
“We know that adjuvant chemotherapy can really help reduce recurrence and prevent breast cancer death. It reduces breast cancer death by about a third,” Mr. Gray noted, giving some background to the analysis. “We are still looking at ways to improve that even further. One of the approaches, which is based on cytokinetic modeling, is to try and increase the dose intensity of the chemotherapy.”
For the meta-analysis, the investigators identified trials that achieved dose intensification by reducing the interval between treatment cycles (a dose-dense approach) and/or by giving drugs sequentially rather than concurrently (allowing delivery of higher doses of each drug).
In all, seven trials, which included 10,004 women in total, tested chemotherapy given every 2 weeks (dose-dense chemotherapy) versus the same chemotherapy given every 3 weeks. Results showed that the former approach netted significantly lower risks of recurrence (rate ratio [RR], 0.83; P = .00004) and breast cancer mortality (RR, 0.86; P = .004), Mr. Gray reported. Absolute gains at 10 years were 4.3% and 2.8%, respectively. Findings were similar after adding five more trials, with another 5,508 women, that had some differences in chemotherapy treatments between arms.
Six trials, which included 11,028 women in total, tested sequential chemotherapy every 3 weeks versus concurrent chemotherapy every 3 weeks. Results showed similarly that the former strategy yielded lower risks of recurrence (RR, 0.87; P = .0006) and breast cancer death (RR, 0.89; P = .03). Absolute gains at 10 years were 3.2% and 2.1%, respectively.
Another six trials, which included a total of 6,532 women, tested sequential chemotherapy given every 2 weeks versus concurrent chemotherapy given every 3 weeks. Results here showed once again that the former yielded lower risks of recurrence (RR, 0.82; P = .0001) and breast cancer mortality (RR, 0.82; P = .001). Absolute gains at 10 years were 4.5% and 3.9%, respectively.
Finally, a pooled analysis of all trials showed that dose intensification reduced the risk of recurrence (RR, 0.85; P less than .00001) and breast cancer mortality (RR, 0.87; P less than .00001). Absolute gains at 10 years were 3.6% and 2.7%, respectively.
“That 13% reduction in breast cancer mortality may seem relatively modest, but given that taxane and anthracycline on a standard schedule reduces your chance of breast cancer death by a third, if you then reduce that by another 15%, then you have got almost 50% of breast cancer deaths by dose-dense taxane and anthracycline chemotherapy,” Mr. Gray pointed out. “So these little step-by-step improvements, it’s really important to identify them, and you get incremental gains which result in breast cancer deaths being about half of what they were 25 or 30 years ago.”
The proportional reduction in risk was similar whether tumors were ER positive or negative, but additional follow-up, especially for the positive tumors, will be important. “We do need longer follow-up in these trials, and sadly, many of the funding bodies are not providing funding for long-term follow-up,” he commented. “This is really valuable information, and we should be following these women up further, out to 20 years, given the long natural history of breast cancer.”
In terms of safety, the dose-intensification strategies were actually associated with lower risks of death without recurrence (RR, 0.85; P less than .02) and all-cause mortality (RR, 0.87; P less than .00001). Findings were similar when analyses focused on the first year of treatment.
Tolerability and toxicities of dose-intense regimens relative to standard regimens were not evaluated by the meta-analysis because these outcomes were reported differently across trials, according to Mr. Gray. However, the investigators did perform a systematic review of health-related quality of life studies that will be part of the final manuscript.
“We found surprisingly little extra toxicity” with the dose intensification, he reported. “It’s not very much considering the extra benefits we are getting. And when you know you are getting more benefit, it makes it easy to tolerate a drug.”
“In the U.S., people have moved toward the accelerated chemotherapy much more than they have in Europe. I think people have the mindset, ‘Well, we’ve always done it this way,’ ” Mr. Gray concluded. “This evidence being so clear and definite will help change that mindset. I wouldn’t be surprised if practice in the U.K. and many other parts of Europe doesn’t switch as a result of these very definite findings.”
SAN ANTONIO – Increasing the dose intensity of adjuvant chemotherapy for breast cancer by spacing cycles more closely or by giving drugs sequentially instead of concurrently improves outcomes, confirms a meta-analysis conducted by the Early Breast Cancer Trialists’ Collaborative Group (EBCTCG).
Investigators led by Richard Gray, MSc, a professor of medical statistics in the Nuffield Department of Population Health at the University of Oxford in Oxford, England, analyzed individual patient data from 25 randomized trials among 34,122 women with early-stage breast cancer.
Results showed that depending on which specific strategy was used, women were 13%-18% less likely to experience recurrence and 11%-18% less likely to die from breast cancer if they were given dose-intensified chemotherapy instead of standard chemotherapy, he reported in a press briefing and a session at the San Antonio Breast Cancer Symposium.
“Shortening the interval between cycles and sequential administration of anthracycline and taxane chemotherapy reduces both recurrence and death from breast cancer,” Mr. Gray summarized. “The reductions are about 15%. They were seen in both estrogen receptor [ER]–positive and ER-negative disease and did not differ significantly by any other tumor or patient characteristics.”
“The beauty of this is these are the exact same drugs and, in many cases, similar doses. It’s just the schedule that changes,” commented press briefing moderator Virginia Kaklamani, MD, a professor of medicine in the division of hematology/oncology at the University of Texas Health Science Center San Antonio and a leader of the Breast Cancer Program at the UT Health San Antonio Cancer Center. “We used to give chemotherapy over 6 months, and with this approach, we can give it over 4 months, so the patients prefer it. The toxicity, with the growth factors for support, can be less. So everybody wins here.”
“Most of us [U.S. oncologists] have been using these [dose-intensification] approaches for the past several years because of a couple pivotal trials. But the benefits from those pivotal trials were not as impressive by themselves,” she added. The meta-analysis shows that “when you give chemotherapy in the right way, you almost double the benefit. So this is huge, even in the era of having immunotherapeutic drugs and all these other targeted drugs. The main treatment I offer my patients every single day is still chemotherapy, and I’d rather make it better and better tolerated.”
Study details
“We know that adjuvant chemotherapy can really help reduce recurrence and prevent breast cancer death. It reduces breast cancer death by about a third,” Mr. Gray noted, giving some background to the analysis. “We are still looking at ways to improve that even further. One of the approaches, which is based on cytokinetic modeling, is to try and increase the dose intensity of the chemotherapy.”
For the meta-analysis, the investigators identified trials that achieved dose intensification by reducing the interval between treatment cycles (a dose-dense approach) and/or by giving drugs sequentially rather than concurrently (allowing delivery of higher doses of each drug).
In all, seven trials, which included 10,004 women in total, tested chemotherapy given every 2 weeks (dose-dense chemotherapy) versus the same chemotherapy given every 3 weeks. Results showed that the former approach netted significantly lower risks of recurrence (rate ratio [RR], 0.83; P = .00004) and breast cancer mortality (RR, 0.86; P = .004), Mr. Gray reported. Absolute gains at 10 years were 4.3% and 2.8%, respectively. Findings were similar after adding five more trials, with another 5,508 women, that had some differences in chemotherapy treatments between arms.
Six trials, which included 11,028 women in total, tested sequential chemotherapy every 3 weeks versus concurrent chemotherapy every 3 weeks. Results showed similarly that the former strategy yielded lower risks of recurrence (RR, 0.87; P = .0006) and breast cancer death (RR, 0.89; P = .03). Absolute gains at 10 years were 3.2% and 2.1%, respectively.
Another six trials, which included a total of 6,532 women, tested sequential chemotherapy given every 2 weeks versus concurrent chemotherapy given every 3 weeks. Results here showed once again that the former yielded lower risks of recurrence (RR, 0.82; P = .0001) and breast cancer mortality (RR, 0.82; P = .001). Absolute gains at 10 years were 4.5% and 3.9%, respectively.
Finally, a pooled analysis of all trials showed that dose intensification reduced the risk of recurrence (RR, 0.85; P less than .00001) and breast cancer mortality (RR, 0.87; P less than .00001). Absolute gains at 10 years were 3.6% and 2.7%, respectively.
“That 13% reduction in breast cancer mortality may seem relatively modest, but given that taxane and anthracycline on a standard schedule reduces your chance of breast cancer death by a third, if you then reduce that by another 15%, then you have got almost 50% of breast cancer deaths by dose-dense taxane and anthracycline chemotherapy,” Mr. Gray pointed out. “So these little step-by-step improvements, it’s really important to identify them, and you get incremental gains which result in breast cancer deaths being about half of what they were 25 or 30 years ago.”
The proportional reduction in risk was similar whether tumors were ER positive or negative, but additional follow-up, especially for the positive tumors, will be important. “We do need longer follow-up in these trials, and sadly, many of the funding bodies are not providing funding for long-term follow-up,” he commented. “This is really valuable information, and we should be following these women up further, out to 20 years, given the long natural history of breast cancer.”
In terms of safety, the dose-intensification strategies were actually associated with lower risks of death without recurrence (RR, 0.85; P less than .02) and all-cause mortality (RR, 0.87; P less than .00001). Findings were similar when analyses focused on the first year of treatment.
Tolerability and toxicities of dose-intense regimens relative to standard regimens were not evaluated by the meta-analysis because these outcomes were reported differently across trials, according to Mr. Gray. However, the investigators did perform a systematic review of health-related quality of life studies that will be part of the final manuscript.
“We found surprisingly little extra toxicity” with the dose intensification, he reported. “It’s not very much considering the extra benefits we are getting. And when you know you are getting more benefit, it makes it easy to tolerate a drug.”
“In the U.S., people have moved toward the accelerated chemotherapy much more than they have in Europe. I think people have the mindset, ‘Well, we’ve always done it this way,’ ” Mr. Gray concluded. “This evidence being so clear and definite will help change that mindset. I wouldn’t be surprised if practice in the U.K. and many other parts of Europe doesn’t switch as a result of these very definite findings.”
SAN ANTONIO – Increasing the dose intensity of adjuvant chemotherapy for breast cancer by spacing cycles more closely or by giving drugs sequentially instead of concurrently improves outcomes, confirms a meta-analysis conducted by the Early Breast Cancer Trialists’ Collaborative Group (EBCTCG).
Investigators led by Richard Gray, MSc, a professor of medical statistics in the Nuffield Department of Population Health at the University of Oxford in Oxford, England, analyzed individual patient data from 25 randomized trials among 34,122 women with early-stage breast cancer.
Results showed that depending on which specific strategy was used, women were 13%-18% less likely to experience recurrence and 11%-18% less likely to die from breast cancer if they were given dose-intensified chemotherapy instead of standard chemotherapy, he reported in a press briefing and a session at the San Antonio Breast Cancer Symposium.
“Shortening the interval between cycles and sequential administration of anthracycline and taxane chemotherapy reduces both recurrence and death from breast cancer,” Mr. Gray summarized. “The reductions are about 15%. They were seen in both estrogen receptor [ER]–positive and ER-negative disease and did not differ significantly by any other tumor or patient characteristics.”
“The beauty of this is these are the exact same drugs and, in many cases, similar doses. It’s just the schedule that changes,” commented press briefing moderator Virginia Kaklamani, MD, a professor of medicine in the division of hematology/oncology at the University of Texas Health Science Center San Antonio and a leader of the Breast Cancer Program at the UT Health San Antonio Cancer Center. “We used to give chemotherapy over 6 months, and with this approach, we can give it over 4 months, so the patients prefer it. The toxicity, with the growth factors for support, can be less. So everybody wins here.”
“Most of us [U.S. oncologists] have been using these [dose-intensification] approaches for the past several years because of a couple pivotal trials. But the benefits from those pivotal trials were not as impressive by themselves,” she added. The meta-analysis shows that “when you give chemotherapy in the right way, you almost double the benefit. So this is huge, even in the era of having immunotherapeutic drugs and all these other targeted drugs. The main treatment I offer my patients every single day is still chemotherapy, and I’d rather make it better and better tolerated.”
Study details
“We know that adjuvant chemotherapy can really help reduce recurrence and prevent breast cancer death. It reduces breast cancer death by about a third,” Mr. Gray noted, giving some background to the analysis. “We are still looking at ways to improve that even further. One of the approaches, which is based on cytokinetic modeling, is to try and increase the dose intensity of the chemotherapy.”
For the meta-analysis, the investigators identified trials that achieved dose intensification by reducing the interval between treatment cycles (a dose-dense approach) and/or by giving drugs sequentially rather than concurrently (allowing delivery of higher doses of each drug).
In all, seven trials, which included 10,004 women in total, tested chemotherapy given every 2 weeks (dose-dense chemotherapy) versus the same chemotherapy given every 3 weeks. Results showed that the former approach netted significantly lower risks of recurrence (rate ratio [RR], 0.83; P = .00004) and breast cancer mortality (RR, 0.86; P = .004), Mr. Gray reported. Absolute gains at 10 years were 4.3% and 2.8%, respectively. Findings were similar after adding five more trials, with another 5,508 women, that had some differences in chemotherapy treatments between arms.
Six trials, which included 11,028 women in total, tested sequential chemotherapy every 3 weeks versus concurrent chemotherapy every 3 weeks. Results showed similarly that the former strategy yielded lower risks of recurrence (RR, 0.87; P = .0006) and breast cancer death (RR, 0.89; P = .03). Absolute gains at 10 years were 3.2% and 2.1%, respectively.
Another six trials, which included a total of 6,532 women, tested sequential chemotherapy given every 2 weeks versus concurrent chemotherapy given every 3 weeks. Results here showed once again that the former yielded lower risks of recurrence (RR, 0.82; P = .0001) and breast cancer mortality (RR, 0.82; P = .001). Absolute gains at 10 years were 4.5% and 3.9%, respectively.
Finally, a pooled analysis of all trials showed that dose intensification reduced the risk of recurrence (RR, 0.85; P less than .00001) and breast cancer mortality (RR, 0.87; P less than .00001). Absolute gains at 10 years were 3.6% and 2.7%, respectively.
“That 13% reduction in breast cancer mortality may seem relatively modest, but given that taxane and anthracycline on a standard schedule reduces your chance of breast cancer death by a third, if you then reduce that by another 15%, then you have got almost 50% of breast cancer deaths by dose-dense taxane and anthracycline chemotherapy,” Mr. Gray pointed out. “So these little step-by-step improvements, it’s really important to identify them, and you get incremental gains which result in breast cancer deaths being about half of what they were 25 or 30 years ago.”
The proportional reduction in risk was similar whether tumors were ER positive or negative, but additional follow-up, especially for the positive tumors, will be important. “We do need longer follow-up in these trials, and sadly, many of the funding bodies are not providing funding for long-term follow-up,” he commented. “This is really valuable information, and we should be following these women up further, out to 20 years, given the long natural history of breast cancer.”
In terms of safety, the dose-intensification strategies were actually associated with lower risks of death without recurrence (RR, 0.85; P less than .02) and all-cause mortality (RR, 0.87; P less than .00001). Findings were similar when analyses focused on the first year of treatment.
Tolerability and toxicities of dose-intense regimens relative to standard regimens were not evaluated by the meta-analysis because these outcomes were reported differently across trials, according to Mr. Gray. However, the investigators did perform a systematic review of health-related quality of life studies that will be part of the final manuscript.
“We found surprisingly little extra toxicity” with the dose intensification, he reported. “It’s not very much considering the extra benefits we are getting. And when you know you are getting more benefit, it makes it easy to tolerate a drug.”
“In the U.S., people have moved toward the accelerated chemotherapy much more than they have in Europe. I think people have the mindset, ‘Well, we’ve always done it this way,’ ” Mr. Gray concluded. “This evidence being so clear and definite will help change that mindset. I wouldn’t be surprised if practice in the U.K. and many other parts of Europe doesn’t switch as a result of these very definite findings.”
REPORTING FROM SABCS 2017
Key clinical point:
Major finding: Compared with standard chemotherapy, dose-intense chemotherapy using various strategies reduced the risk of recurrence (rate ratio, 0.85; P less than .00001) and breast cancer mortality (RR, 0.87; P less than .00001).
Data source: A meta-analysis of individual patient data from 25 randomized trials among 34,122 women with early-stage breast cancer.
Disclosures: Mr. Gray disclosed that he had no relevant conflicts of interest.