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Use of antipsychotics that increase prolactin levels is significantly associated with an increased risk for breast cancer in women with schizophrenia, new research suggests. However, at least one expert says that, at this point, clinical implications are premature.

Investigators compared data from Finnish nationwide registers on more than 30,000 women diagnosed with schizophrenia. Of those patients, 1,069 were diagnosed with breast cancer. Results showed that long-term exposure to prolactin-increasing antipsychotics was associated with a 56% increased risk of developing breast cancer in comparison with exposure of short duration. No significant association was found with cumulative exposure to prolactin-sparing antipsychotics.

“In case of planning for long-term antipsychotic [therapy], prefer non–prolactin-raising antipsychotics in females and inform patients about a potential risk to allow for informed shared decision-making,” study coauthor Christoph U. Correll, MD, professor of psychiatry and molecular medicine at Hofstra University, Hempstead, N.Y., told this news organization.

“Monitoring prolactinemia and addressing hyperprolactinemia are important in women with schizophrenia who are treated with prolactin-increasing antipsychotics,” he said.

The study was published online Aug. 30, 2021, in The Lancet.
 

A ‘relevant contribution’

Breast cancer is 25% more prevalent among women with schizophrenia than among women in the general population. Antipsychotics have long been suspected as a potential culprit, but research results have been inconsistent, said Dr. Correll.

In addition, high concentrations of prolactin are associated with a higher risk of developing breast cancer, but most previous research did not distinguish between antipsychotics that increased prolactin levels those that did not.

Dr. Correll and colleagues “wanted to add to this literature by utilizing a generalizable nationwide sample with a sufficient large number of patients and sufficiently long follow-up to address the clinically very relevant question whether antipsychotic use could increase the risk of breast cancer.”

They also believed that grouping antipsychotics into prolactin-raising and non–prolactin-raising agents would be “a relevant contribution.”

The researchers drew on data from several large Finnish databases to conduct a nested case-control study of 30,785 women aged at least16 years who were diagnosed with schizophrenia between 1972 and 2014.

Of these patients, 1,069 received an initial diagnosis of invasive breast cancer (after being diagnosed with schizophrenia) between 2000 and 2017. These case patients were compared to 5,339 matched control patients. The mean age of the case patients and the control patients was 62 years. The mean time since initial diagnosis of schizophrenia was 24 years.

Antipsychotic use was divided into three periods: less than 1 year, 1-4 years, and ≥5 years. Antipsychotics were further divided into prolactin-increasing or prolactin-sparing drugs (for example, clozapine, quetiapine, or aripiprazole). Breast cancer was divided into either lobular or ductal adenocarcinoma.

In their statistical analyses, the researchers adjusted for an array of covariates, including previous diagnoses of other medical conditions, drugs that may modify the risk for breast cancer (for example, beta-blockers, calcium channel blockers, spironolactone, loop diuretics, and statins), substance misuse, suicide attempt, parity, and use of hormone replacement therapy (HRT).
 

‘Clinically meaningful’ risk

Ductal adenocarcinoma was more common than lobular adenocarcinoma (73% vs. 20% among case patients). A higher proportion of case patients used cardiovascular medications and HRT, compared with control patients.

A higher proportion of case patients had used prolactin-increasing antipsychotics for at least 5 years, compared with control patients (71.4% vs. 64.3%; adjusted odds ratio, 1.56; 95% CI, 1.27-1.92; P < .0001) in comparison with minimal exposure (<1 year) to prolactin-increasing antipsychotics.

On the other hand, a similar proportion of case patients and control patients used prolactin-sparing antipsychotics for at least 5 years (8.3 vs. 8.2%; aOR, 1.19; 95% CI, 0.90-1.58); the OR of 1.19 was not deemed significant.

Although exposure of ≥5 years to prolactin-increasing antipsychotics was associated with an increased risk for both types of adenocarcinoma, the risk was higher for lobular than for ductal disease (aOR, 2.36; 95% CI, 1.46-3.82 vs. aOR, 1.42; 95% CI, 1.12-1.80).

“Conservatively, if we subtract the 19% nonsignificantly increased odds with prolactin-sparing antipsychotics from the 56% significantly increased odds with prolactin-increasing antipsychotics, we obtain a 37% relative increase in odds,” the authors noted.

“Using a lifetime incidence of breast cancer in women in the general population of about 12%, with a somewhat higher lifetime incidence in patients with schizophrenia than the general population, this difference between prolactin-increasing versus prolactin-sparing antipsychotics in breast cancer risk upon exposure of 5 or more years would correspond to about a 4% (37% x 12%) increase in absolute breast cancer odds with prolactin-increasing antipsychotic treatment” – a difference the authors call “clinically meaningful.”

Correll noted that although the study was conducted in a Finnish population, the findings are generalizable to other populations.
 

Clinical implications premature?

Commenting on the study, Anton Pottegård, MScPharm, PhD, DMSc, professor of pharmacoepidemiology, department of public health, University of Southern Denmark, Odense, expressed concern that “this new study is fairly aggressive in its recommendation [that] we need to pay attention to hyperprolactinemia, as this seems to cause breast cancer.”

Dr. Pottegård, who is also the head of research, Hospital Pharmacy Funen, Odense University Hospital, who was not involved with the study, said he does not “think that the full body of the literature supports such a direct conclusion and/or direct inference to clinical practice.”

Although “this is an important study to further this work, I do not think we are at a place (yet) where it should lead to different action from clinicians,” Dr. Pottegård cautioned.

Also commenting on the study, Mary Seeman, MDCM, DSc, professor emeritus of neurosciences and clinical translation, department of psychiatry, University of Toronto, called the question of whether prolactin-increasing antipsychotics increase breast cancer risk “very complicated because the incidence of breast cancer ... is higher in women with schizophrenia than in other women.”

Dr. Seeman, who was not involved with the study, pointed to other reasons for the increased risk, including higher rates of obesity, substance abuse, cigarette smoking, stress, and sedentary behavior, all of which raise prolactin levels. Additionally, “protective factors such as pregnancies and breastfeeding are less frequent in women with schizophrenia than in their peers.” Women with schizophrenia also “tend not to do breast screening, see their doctors less often, follow doctors’ orders less rigorously, and obtain treatment less often.”

The take-home message “is to prescribe prolactin-sparing medication to women if at all possible – but until we know more, that is good advice, although not always possible because the illness for which the antipsychotics are prescribed may not respond to those particular medications,” Dr. Seeman said.

The study was funded by the Finnish Ministry of Social Affairs and Health through the developmental fund for Niuvanniemi Hospital. Funding was also provided to individual researchers by the Academy of Finland, the Finnish Medical Foundation, and the Emil Aaltonen foundation. Dr. Correll has been a consultant or advisor to or has received honoraria from numerous companies. He has provided expert testimony for Janssen and Otsuka; received royalties from UpToDate and is a stock option holder of LB Pharma; served on a data safety monitoring board for Lundbeck, Rovi, Supernus, and Teva; and received grant support from Janssen and Takeda. Dr. Pottegård and Dr. Seeman disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Use of antipsychotics that increase prolactin levels is significantly associated with an increased risk for breast cancer in women with schizophrenia, new research suggests. However, at least one expert says that, at this point, clinical implications are premature.

Investigators compared data from Finnish nationwide registers on more than 30,000 women diagnosed with schizophrenia. Of those patients, 1,069 were diagnosed with breast cancer. Results showed that long-term exposure to prolactin-increasing antipsychotics was associated with a 56% increased risk of developing breast cancer in comparison with exposure of short duration. No significant association was found with cumulative exposure to prolactin-sparing antipsychotics.

“In case of planning for long-term antipsychotic [therapy], prefer non–prolactin-raising antipsychotics in females and inform patients about a potential risk to allow for informed shared decision-making,” study coauthor Christoph U. Correll, MD, professor of psychiatry and molecular medicine at Hofstra University, Hempstead, N.Y., told this news organization.

“Monitoring prolactinemia and addressing hyperprolactinemia are important in women with schizophrenia who are treated with prolactin-increasing antipsychotics,” he said.

The study was published online Aug. 30, 2021, in The Lancet.
 

A ‘relevant contribution’

Breast cancer is 25% more prevalent among women with schizophrenia than among women in the general population. Antipsychotics have long been suspected as a potential culprit, but research results have been inconsistent, said Dr. Correll.

In addition, high concentrations of prolactin are associated with a higher risk of developing breast cancer, but most previous research did not distinguish between antipsychotics that increased prolactin levels those that did not.

Dr. Correll and colleagues “wanted to add to this literature by utilizing a generalizable nationwide sample with a sufficient large number of patients and sufficiently long follow-up to address the clinically very relevant question whether antipsychotic use could increase the risk of breast cancer.”

They also believed that grouping antipsychotics into prolactin-raising and non–prolactin-raising agents would be “a relevant contribution.”

The researchers drew on data from several large Finnish databases to conduct a nested case-control study of 30,785 women aged at least16 years who were diagnosed with schizophrenia between 1972 and 2014.

Of these patients, 1,069 received an initial diagnosis of invasive breast cancer (after being diagnosed with schizophrenia) between 2000 and 2017. These case patients were compared to 5,339 matched control patients. The mean age of the case patients and the control patients was 62 years. The mean time since initial diagnosis of schizophrenia was 24 years.

Antipsychotic use was divided into three periods: less than 1 year, 1-4 years, and ≥5 years. Antipsychotics were further divided into prolactin-increasing or prolactin-sparing drugs (for example, clozapine, quetiapine, or aripiprazole). Breast cancer was divided into either lobular or ductal adenocarcinoma.

In their statistical analyses, the researchers adjusted for an array of covariates, including previous diagnoses of other medical conditions, drugs that may modify the risk for breast cancer (for example, beta-blockers, calcium channel blockers, spironolactone, loop diuretics, and statins), substance misuse, suicide attempt, parity, and use of hormone replacement therapy (HRT).
 

‘Clinically meaningful’ risk

Ductal adenocarcinoma was more common than lobular adenocarcinoma (73% vs. 20% among case patients). A higher proportion of case patients used cardiovascular medications and HRT, compared with control patients.

A higher proportion of case patients had used prolactin-increasing antipsychotics for at least 5 years, compared with control patients (71.4% vs. 64.3%; adjusted odds ratio, 1.56; 95% CI, 1.27-1.92; P < .0001) in comparison with minimal exposure (<1 year) to prolactin-increasing antipsychotics.

On the other hand, a similar proportion of case patients and control patients used prolactin-sparing antipsychotics for at least 5 years (8.3 vs. 8.2%; aOR, 1.19; 95% CI, 0.90-1.58); the OR of 1.19 was not deemed significant.

Although exposure of ≥5 years to prolactin-increasing antipsychotics was associated with an increased risk for both types of adenocarcinoma, the risk was higher for lobular than for ductal disease (aOR, 2.36; 95% CI, 1.46-3.82 vs. aOR, 1.42; 95% CI, 1.12-1.80).

“Conservatively, if we subtract the 19% nonsignificantly increased odds with prolactin-sparing antipsychotics from the 56% significantly increased odds with prolactin-increasing antipsychotics, we obtain a 37% relative increase in odds,” the authors noted.

“Using a lifetime incidence of breast cancer in women in the general population of about 12%, with a somewhat higher lifetime incidence in patients with schizophrenia than the general population, this difference between prolactin-increasing versus prolactin-sparing antipsychotics in breast cancer risk upon exposure of 5 or more years would correspond to about a 4% (37% x 12%) increase in absolute breast cancer odds with prolactin-increasing antipsychotic treatment” – a difference the authors call “clinically meaningful.”

Correll noted that although the study was conducted in a Finnish population, the findings are generalizable to other populations.
 

Clinical implications premature?

Commenting on the study, Anton Pottegård, MScPharm, PhD, DMSc, professor of pharmacoepidemiology, department of public health, University of Southern Denmark, Odense, expressed concern that “this new study is fairly aggressive in its recommendation [that] we need to pay attention to hyperprolactinemia, as this seems to cause breast cancer.”

Dr. Pottegård, who is also the head of research, Hospital Pharmacy Funen, Odense University Hospital, who was not involved with the study, said he does not “think that the full body of the literature supports such a direct conclusion and/or direct inference to clinical practice.”

Although “this is an important study to further this work, I do not think we are at a place (yet) where it should lead to different action from clinicians,” Dr. Pottegård cautioned.

Also commenting on the study, Mary Seeman, MDCM, DSc, professor emeritus of neurosciences and clinical translation, department of psychiatry, University of Toronto, called the question of whether prolactin-increasing antipsychotics increase breast cancer risk “very complicated because the incidence of breast cancer ... is higher in women with schizophrenia than in other women.”

Dr. Seeman, who was not involved with the study, pointed to other reasons for the increased risk, including higher rates of obesity, substance abuse, cigarette smoking, stress, and sedentary behavior, all of which raise prolactin levels. Additionally, “protective factors such as pregnancies and breastfeeding are less frequent in women with schizophrenia than in their peers.” Women with schizophrenia also “tend not to do breast screening, see their doctors less often, follow doctors’ orders less rigorously, and obtain treatment less often.”

The take-home message “is to prescribe prolactin-sparing medication to women if at all possible – but until we know more, that is good advice, although not always possible because the illness for which the antipsychotics are prescribed may not respond to those particular medications,” Dr. Seeman said.

The study was funded by the Finnish Ministry of Social Affairs and Health through the developmental fund for Niuvanniemi Hospital. Funding was also provided to individual researchers by the Academy of Finland, the Finnish Medical Foundation, and the Emil Aaltonen foundation. Dr. Correll has been a consultant or advisor to or has received honoraria from numerous companies. He has provided expert testimony for Janssen and Otsuka; received royalties from UpToDate and is a stock option holder of LB Pharma; served on a data safety monitoring board for Lundbeck, Rovi, Supernus, and Teva; and received grant support from Janssen and Takeda. Dr. Pottegård and Dr. Seeman disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Use of antipsychotics that increase prolactin levels is significantly associated with an increased risk for breast cancer in women with schizophrenia, new research suggests. However, at least one expert says that, at this point, clinical implications are premature.

Investigators compared data from Finnish nationwide registers on more than 30,000 women diagnosed with schizophrenia. Of those patients, 1,069 were diagnosed with breast cancer. Results showed that long-term exposure to prolactin-increasing antipsychotics was associated with a 56% increased risk of developing breast cancer in comparison with exposure of short duration. No significant association was found with cumulative exposure to prolactin-sparing antipsychotics.

“In case of planning for long-term antipsychotic [therapy], prefer non–prolactin-raising antipsychotics in females and inform patients about a potential risk to allow for informed shared decision-making,” study coauthor Christoph U. Correll, MD, professor of psychiatry and molecular medicine at Hofstra University, Hempstead, N.Y., told this news organization.

“Monitoring prolactinemia and addressing hyperprolactinemia are important in women with schizophrenia who are treated with prolactin-increasing antipsychotics,” he said.

The study was published online Aug. 30, 2021, in The Lancet.
 

A ‘relevant contribution’

Breast cancer is 25% more prevalent among women with schizophrenia than among women in the general population. Antipsychotics have long been suspected as a potential culprit, but research results have been inconsistent, said Dr. Correll.

In addition, high concentrations of prolactin are associated with a higher risk of developing breast cancer, but most previous research did not distinguish between antipsychotics that increased prolactin levels those that did not.

Dr. Correll and colleagues “wanted to add to this literature by utilizing a generalizable nationwide sample with a sufficient large number of patients and sufficiently long follow-up to address the clinically very relevant question whether antipsychotic use could increase the risk of breast cancer.”

They also believed that grouping antipsychotics into prolactin-raising and non–prolactin-raising agents would be “a relevant contribution.”

The researchers drew on data from several large Finnish databases to conduct a nested case-control study of 30,785 women aged at least16 years who were diagnosed with schizophrenia between 1972 and 2014.

Of these patients, 1,069 received an initial diagnosis of invasive breast cancer (after being diagnosed with schizophrenia) between 2000 and 2017. These case patients were compared to 5,339 matched control patients. The mean age of the case patients and the control patients was 62 years. The mean time since initial diagnosis of schizophrenia was 24 years.

Antipsychotic use was divided into three periods: less than 1 year, 1-4 years, and ≥5 years. Antipsychotics were further divided into prolactin-increasing or prolactin-sparing drugs (for example, clozapine, quetiapine, or aripiprazole). Breast cancer was divided into either lobular or ductal adenocarcinoma.

In their statistical analyses, the researchers adjusted for an array of covariates, including previous diagnoses of other medical conditions, drugs that may modify the risk for breast cancer (for example, beta-blockers, calcium channel blockers, spironolactone, loop diuretics, and statins), substance misuse, suicide attempt, parity, and use of hormone replacement therapy (HRT).
 

‘Clinically meaningful’ risk

Ductal adenocarcinoma was more common than lobular adenocarcinoma (73% vs. 20% among case patients). A higher proportion of case patients used cardiovascular medications and HRT, compared with control patients.

A higher proportion of case patients had used prolactin-increasing antipsychotics for at least 5 years, compared with control patients (71.4% vs. 64.3%; adjusted odds ratio, 1.56; 95% CI, 1.27-1.92; P < .0001) in comparison with minimal exposure (<1 year) to prolactin-increasing antipsychotics.

On the other hand, a similar proportion of case patients and control patients used prolactin-sparing antipsychotics for at least 5 years (8.3 vs. 8.2%; aOR, 1.19; 95% CI, 0.90-1.58); the OR of 1.19 was not deemed significant.

Although exposure of ≥5 years to prolactin-increasing antipsychotics was associated with an increased risk for both types of adenocarcinoma, the risk was higher for lobular than for ductal disease (aOR, 2.36; 95% CI, 1.46-3.82 vs. aOR, 1.42; 95% CI, 1.12-1.80).

“Conservatively, if we subtract the 19% nonsignificantly increased odds with prolactin-sparing antipsychotics from the 56% significantly increased odds with prolactin-increasing antipsychotics, we obtain a 37% relative increase in odds,” the authors noted.

“Using a lifetime incidence of breast cancer in women in the general population of about 12%, with a somewhat higher lifetime incidence in patients with schizophrenia than the general population, this difference between prolactin-increasing versus prolactin-sparing antipsychotics in breast cancer risk upon exposure of 5 or more years would correspond to about a 4% (37% x 12%) increase in absolute breast cancer odds with prolactin-increasing antipsychotic treatment” – a difference the authors call “clinically meaningful.”

Correll noted that although the study was conducted in a Finnish population, the findings are generalizable to other populations.
 

Clinical implications premature?

Commenting on the study, Anton Pottegård, MScPharm, PhD, DMSc, professor of pharmacoepidemiology, department of public health, University of Southern Denmark, Odense, expressed concern that “this new study is fairly aggressive in its recommendation [that] we need to pay attention to hyperprolactinemia, as this seems to cause breast cancer.”

Dr. Pottegård, who is also the head of research, Hospital Pharmacy Funen, Odense University Hospital, who was not involved with the study, said he does not “think that the full body of the literature supports such a direct conclusion and/or direct inference to clinical practice.”

Although “this is an important study to further this work, I do not think we are at a place (yet) where it should lead to different action from clinicians,” Dr. Pottegård cautioned.

Also commenting on the study, Mary Seeman, MDCM, DSc, professor emeritus of neurosciences and clinical translation, department of psychiatry, University of Toronto, called the question of whether prolactin-increasing antipsychotics increase breast cancer risk “very complicated because the incidence of breast cancer ... is higher in women with schizophrenia than in other women.”

Dr. Seeman, who was not involved with the study, pointed to other reasons for the increased risk, including higher rates of obesity, substance abuse, cigarette smoking, stress, and sedentary behavior, all of which raise prolactin levels. Additionally, “protective factors such as pregnancies and breastfeeding are less frequent in women with schizophrenia than in their peers.” Women with schizophrenia also “tend not to do breast screening, see their doctors less often, follow doctors’ orders less rigorously, and obtain treatment less often.”

The take-home message “is to prescribe prolactin-sparing medication to women if at all possible – but until we know more, that is good advice, although not always possible because the illness for which the antipsychotics are prescribed may not respond to those particular medications,” Dr. Seeman said.

The study was funded by the Finnish Ministry of Social Affairs and Health through the developmental fund for Niuvanniemi Hospital. Funding was also provided to individual researchers by the Academy of Finland, the Finnish Medical Foundation, and the Emil Aaltonen foundation. Dr. Correll has been a consultant or advisor to or has received honoraria from numerous companies. He has provided expert testimony for Janssen and Otsuka; received royalties from UpToDate and is a stock option holder of LB Pharma; served on a data safety monitoring board for Lundbeck, Rovi, Supernus, and Teva; and received grant support from Janssen and Takeda. Dr. Pottegård and Dr. Seeman disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Another study has shown an association between antibiotic use and an increased risk for colon cancer.

The latest data come from a Swedish population study. Investigators analyzed data from more than 40,000 colorectal cancer patients and 200,000 cancer-free control persons.

Sheep purple/flickr/CC BY 2.0 /en.wikipedia/CC BY-SA 4.0

They found that moderate use of antibiotics increased the risk for proximal colon cancer by 9% and that very high antibiotic use increased the risk by 17%.

In contrast, the risk for rectal cancer was reduced by 4% with moderate use and 9% with very high use, but this association was confined to women.

Antibiotic use was categorized as no use (no reported use of antibiotics during the study period), low (use during a period of 1-10 days), moderate (11-60 days), high (61-180 days), and very high (>180 days).

The study, led by Sophia Harlid, PhD, department of radiation sciences, oncology, Umeå University, Sweden, was published online on Sept. 1 in the Journal of the National Cancer Institute.

The results complement findings from a recent study from Scotland, which found that a history of antibiotic use among individuals younger than 50 appeared to increase the risk of developing colon cancer but not rectal cancer by 49%.

The new data from Sweden “strengthen prior evidence and provide new insights into site-specific carcinogenesis as well as indirect support for the role of gut microbiota,” lead author Dr. Dr. Harlid commented in an interview.

“The positive associations between antibiotics use and proximal colon cancer began at the lowest level of antibiotics use, providing a potential justification for reducing antibiotics prescriptions in clinical practice,” she added.

In their article, the team suggests that the increased risk could be a result of antibiotics having a “disruptive effect” on the gut microbiome.

The finding of an increased risk for cancer in the proximal colon but not further along the alimentary tract “is consistent with a high microbial impact in the proximal colon and a decreasing concentration of short-chain fatty acids along the colon,” the authors comment.

This results “in higher bacterial activity, biofilm formation, and fermentation in the proximal compared with the distal colon and rectum.”

A further analysis showed that the use of quinolones and sulfonamides and/or trimethoprims was associated with an increased risk for proximal colon cancer, whereas use of nitrofurantoins, macrolides and/or lincosamides, and metronidazoles and/or tinidazoles was inversely associated with rectal cancer.

Details of the study findings

For their study, the team analyzed complete-population data from Swedish national registers for the period July 1, 2005 to Dec. 31, 2016.

They matched case patients who were diagnosed with colorectal cancer from Jan. 1, 2010 to Dec. 31, 2016 with cancer-free control persons in a 1:5 ratio. Data on antibiotic use were extracted from the Swedish Prescribed Drug Register.

Other variables, such as socioeconomic factors and health care utilization, were obtained from the Swedish Inpatient Register and the Longitudinal Integration Database for Health Insurance and Labor Market Studies.

The team identified 40,545 patients with colorectal cancer cases; there were 202,720 control persons. Just over half (52.9%) of the participants were men; the mean age at cancer diagnosis was 72 years. Among the cases, 36.4% were proximal colon cancers, 29.3% were distal colon cancers, and 33.0% rectal cancers.

Control patients were more likely to have been prescribed no antibiotics, at 22.4% versus 18.7% for case patients. Case patients were more likely than control persons to have used antibiotics for more than 2 months, at 20.8% versus 19.3% (P < .001).

Overall, antibiotic use was positively associated with colorectal cancer. In comparison with no use, the odds ratio for moderate use was 1.15; for very high use, it was 1.17 (P < .001 for trend).

Excluding all antibiotic use during the 2 years prior to a colorectal cancer diagnosis attenuated the association, such that it was no longer significant for very high use versus no antibiotic use.

Applying this cutoff to the remaining analyses, the team found that the dose-response relationship between antibiotic use and colorectal cancer was largely confined to proximal colon cancer, at an odds ratio of 1.09 for moderate use and 1.17 for very high use in comparison with no use (P < .001 for trend).

For distal colon cancer, the relationship was “close to null.”

There was a slight inverse relationship between rectal cancer and antibiotic use, at an odds rate of 0.96 for moderate use and 0.91 for very high use versus no use (P < .001 for trend). This association was found in women only, whereas the other associations were seen in both men and women.

The study was supported by the Lion’s Cancer Research Foundation, Umeå University, and Region Västerbotten. Dr. Harlid has disclosed no relevant financial relationships. Three coauthors report various relationships with industry, as noted in the original article.

A version of this article first appeared on Medscape.com.

Another study has shown an association between antibiotic use and an increased risk for colon cancer.

The latest data come from a Swedish population study. Investigators analyzed data from more than 40,000 colorectal cancer patients and 200,000 cancer-free control persons.

Sheep purple/flickr/CC BY 2.0 /en.wikipedia/CC BY-SA 4.0

They found that moderate use of antibiotics increased the risk for proximal colon cancer by 9% and that very high antibiotic use increased the risk by 17%.

In contrast, the risk for rectal cancer was reduced by 4% with moderate use and 9% with very high use, but this association was confined to women.

Antibiotic use was categorized as no use (no reported use of antibiotics during the study period), low (use during a period of 1-10 days), moderate (11-60 days), high (61-180 days), and very high (>180 days).

The study, led by Sophia Harlid, PhD, department of radiation sciences, oncology, Umeå University, Sweden, was published online on Sept. 1 in the Journal of the National Cancer Institute.

The results complement findings from a recent study from Scotland, which found that a history of antibiotic use among individuals younger than 50 appeared to increase the risk of developing colon cancer but not rectal cancer by 49%.

The new data from Sweden “strengthen prior evidence and provide new insights into site-specific carcinogenesis as well as indirect support for the role of gut microbiota,” lead author Dr. Dr. Harlid commented in an interview.

“The positive associations between antibiotics use and proximal colon cancer began at the lowest level of antibiotics use, providing a potential justification for reducing antibiotics prescriptions in clinical practice,” she added.

In their article, the team suggests that the increased risk could be a result of antibiotics having a “disruptive effect” on the gut microbiome.

The finding of an increased risk for cancer in the proximal colon but not further along the alimentary tract “is consistent with a high microbial impact in the proximal colon and a decreasing concentration of short-chain fatty acids along the colon,” the authors comment.

This results “in higher bacterial activity, biofilm formation, and fermentation in the proximal compared with the distal colon and rectum.”

A further analysis showed that the use of quinolones and sulfonamides and/or trimethoprims was associated with an increased risk for proximal colon cancer, whereas use of nitrofurantoins, macrolides and/or lincosamides, and metronidazoles and/or tinidazoles was inversely associated with rectal cancer.

Details of the study findings

For their study, the team analyzed complete-population data from Swedish national registers for the period July 1, 2005 to Dec. 31, 2016.

They matched case patients who were diagnosed with colorectal cancer from Jan. 1, 2010 to Dec. 31, 2016 with cancer-free control persons in a 1:5 ratio. Data on antibiotic use were extracted from the Swedish Prescribed Drug Register.

Other variables, such as socioeconomic factors and health care utilization, were obtained from the Swedish Inpatient Register and the Longitudinal Integration Database for Health Insurance and Labor Market Studies.

The team identified 40,545 patients with colorectal cancer cases; there were 202,720 control persons. Just over half (52.9%) of the participants were men; the mean age at cancer diagnosis was 72 years. Among the cases, 36.4% were proximal colon cancers, 29.3% were distal colon cancers, and 33.0% rectal cancers.

Control patients were more likely to have been prescribed no antibiotics, at 22.4% versus 18.7% for case patients. Case patients were more likely than control persons to have used antibiotics for more than 2 months, at 20.8% versus 19.3% (P < .001).

Overall, antibiotic use was positively associated with colorectal cancer. In comparison with no use, the odds ratio for moderate use was 1.15; for very high use, it was 1.17 (P < .001 for trend).

Excluding all antibiotic use during the 2 years prior to a colorectal cancer diagnosis attenuated the association, such that it was no longer significant for very high use versus no antibiotic use.

Applying this cutoff to the remaining analyses, the team found that the dose-response relationship between antibiotic use and colorectal cancer was largely confined to proximal colon cancer, at an odds ratio of 1.09 for moderate use and 1.17 for very high use in comparison with no use (P < .001 for trend).

For distal colon cancer, the relationship was “close to null.”

There was a slight inverse relationship between rectal cancer and antibiotic use, at an odds rate of 0.96 for moderate use and 0.91 for very high use versus no use (P < .001 for trend). This association was found in women only, whereas the other associations were seen in both men and women.

The study was supported by the Lion’s Cancer Research Foundation, Umeå University, and Region Västerbotten. Dr. Harlid has disclosed no relevant financial relationships. Three coauthors report various relationships with industry, as noted in the original article.

A version of this article first appeared on Medscape.com.

Another study has shown an association between antibiotic use and an increased risk for colon cancer.

The latest data come from a Swedish population study. Investigators analyzed data from more than 40,000 colorectal cancer patients and 200,000 cancer-free control persons.

Sheep purple/flickr/CC BY 2.0 /en.wikipedia/CC BY-SA 4.0

They found that moderate use of antibiotics increased the risk for proximal colon cancer by 9% and that very high antibiotic use increased the risk by 17%.

In contrast, the risk for rectal cancer was reduced by 4% with moderate use and 9% with very high use, but this association was confined to women.

Antibiotic use was categorized as no use (no reported use of antibiotics during the study period), low (use during a period of 1-10 days), moderate (11-60 days), high (61-180 days), and very high (>180 days).

The study, led by Sophia Harlid, PhD, department of radiation sciences, oncology, Umeå University, Sweden, was published online on Sept. 1 in the Journal of the National Cancer Institute.

The results complement findings from a recent study from Scotland, which found that a history of antibiotic use among individuals younger than 50 appeared to increase the risk of developing colon cancer but not rectal cancer by 49%.

The new data from Sweden “strengthen prior evidence and provide new insights into site-specific carcinogenesis as well as indirect support for the role of gut microbiota,” lead author Dr. Dr. Harlid commented in an interview.

“The positive associations between antibiotics use and proximal colon cancer began at the lowest level of antibiotics use, providing a potential justification for reducing antibiotics prescriptions in clinical practice,” she added.

In their article, the team suggests that the increased risk could be a result of antibiotics having a “disruptive effect” on the gut microbiome.

The finding of an increased risk for cancer in the proximal colon but not further along the alimentary tract “is consistent with a high microbial impact in the proximal colon and a decreasing concentration of short-chain fatty acids along the colon,” the authors comment.

This results “in higher bacterial activity, biofilm formation, and fermentation in the proximal compared with the distal colon and rectum.”

A further analysis showed that the use of quinolones and sulfonamides and/or trimethoprims was associated with an increased risk for proximal colon cancer, whereas use of nitrofurantoins, macrolides and/or lincosamides, and metronidazoles and/or tinidazoles was inversely associated with rectal cancer.

Details of the study findings

For their study, the team analyzed complete-population data from Swedish national registers for the period July 1, 2005 to Dec. 31, 2016.

They matched case patients who were diagnosed with colorectal cancer from Jan. 1, 2010 to Dec. 31, 2016 with cancer-free control persons in a 1:5 ratio. Data on antibiotic use were extracted from the Swedish Prescribed Drug Register.

Other variables, such as socioeconomic factors and health care utilization, were obtained from the Swedish Inpatient Register and the Longitudinal Integration Database for Health Insurance and Labor Market Studies.

The team identified 40,545 patients with colorectal cancer cases; there were 202,720 control persons. Just over half (52.9%) of the participants were men; the mean age at cancer diagnosis was 72 years. Among the cases, 36.4% were proximal colon cancers, 29.3% were distal colon cancers, and 33.0% rectal cancers.

Control patients were more likely to have been prescribed no antibiotics, at 22.4% versus 18.7% for case patients. Case patients were more likely than control persons to have used antibiotics for more than 2 months, at 20.8% versus 19.3% (P < .001).

Overall, antibiotic use was positively associated with colorectal cancer. In comparison with no use, the odds ratio for moderate use was 1.15; for very high use, it was 1.17 (P < .001 for trend).

Excluding all antibiotic use during the 2 years prior to a colorectal cancer diagnosis attenuated the association, such that it was no longer significant for very high use versus no antibiotic use.

Applying this cutoff to the remaining analyses, the team found that the dose-response relationship between antibiotic use and colorectal cancer was largely confined to proximal colon cancer, at an odds ratio of 1.09 for moderate use and 1.17 for very high use in comparison with no use (P < .001 for trend).

For distal colon cancer, the relationship was “close to null.”

There was a slight inverse relationship between rectal cancer and antibiotic use, at an odds rate of 0.96 for moderate use and 0.91 for very high use versus no use (P < .001 for trend). This association was found in women only, whereas the other associations were seen in both men and women.

The study was supported by the Lion’s Cancer Research Foundation, Umeå University, and Region Västerbotten. Dr. Harlid has disclosed no relevant financial relationships. Three coauthors report various relationships with industry, as noted in the original article.

A version of this article first appeared on Medscape.com.

Although enrollment into lung cancer clinical trials fell during the early months of the COVID-19 pandemic, it increased after a number of mitigation strategies were introduced.

These strategies should now be maintained, say experts, in order to improve enrollment and access to trials and to ensure that trials are more pragmatic and streamlined.

These were the findings from a survey sent to 173 sites of clinical trials in 45 countries around the world. The findings were presented recently at the World Conference on Lung Cancer (WCLC) 2021. The meeting and the survey were organized by the International Association for the Study of Lung Cancer (IASLC).

Responses to the survey revealed that enrollment into lung cancer trials fell by 43% during the early months of the pandemic. Patients stopped attending clinics, and some trials were suspended.

Patients were less willing to visit clinical trial sites, and lockdown restrictions made travel difficult.

Organizers of clinical trials responded by implementing mitigation strategies, such as changing monitoring requirements, increasing use of telehealth, and using local non-study facilities for laboratory and radiology services.

These measures led to an increase in trial enrollment toward the end of 2020, the survey results show.

“The COVID-19 pandemic created many challenges [that led to] reductions in lung cancer clinical trial enrollment,” commented study presenter Matthew P. Smeltzer, PhD, from the Division of Epidemiology, Biostatistics, and Environmental Health, University of Memphis.

The employment of mitigation strategies allowed the removal of “barriers,” and although the pandemic “worsened, trial enrollment began to improve due in part to these strategies,” Dr. Smeltzer said.

Many of these measures were successful and should be maintained, he suggested. Strategies include allowing telehealth visits, performing testing at local laboratories, using local radiology services, mailing experimental agents “where possible,” and allowing flexibility in trial schedules.

This is a “very important” study, commented Marina Garassino, MD, professor of medicine, hematology, and oncology, the University of Chicago Medicine, in her discussion of the abstract.

Irrespective of the pandemic, the regulation and the bureaucracy of clinical trials hinder participation by patients and physicians, she said.

Many of the mitigation strategies highlighted by the survey were similar to recommendations on the conduct of clinical trials published by the American Society of Clinical Oncology during the pandemic. Those recommendations emphasize the use of telehealth and offsite strategies to help with patient monitoring, she noted.

The findings from the survey show that it is possible to conduct more “streamlined and pragmatic trials,” she said.

“More flexible approaches should be approved by the sponsors of clinical trials and global regulatory bodies,” she added.

However, she expressed concern that “with the telehealth visits, we can create some disparities.”

“We have to remember that lung cancer patients are sometimes a very old population, and they are not digitally evolved,” she commented.

Commenting on Twitter, Jennifer C. King, PhD, chief scientific officer at the GO2 Foundation for Lung Cancer, in Washington, D.C., agreed that many of the mitigation strategies identified in the study “are good for patients all of the time, not just during a pandemic.”

Impact on lung cancer clinical trials

The survey, which included 64 questions, was intended to assess the impact of the COVID pandemic on lung cancer clinical trials.

Most of the survey responses came from sites in Europe (37.6%); 21.4% came from Asia, 13.3% came from the United States, and 7.5% came from Canada.

The team found that enrollment into lung cancer trials declined by 43% in 2020 compared to 2019, at an incidence rate ratio of 0.57 (P = .0115).

The largest decreases in enrollment were between April and August 2020, Dr. Smeltzer noted. However, in the last quarter of 2020 (October to December), the differences in enrollment were significantly smaller (P = .0160), despite a marked increase in global COVID-19 cases per month, he added.

The most common challenges faced by clinical trial sites during the pandemic were the following: There were fewer eligible patients (cited by 67% of respondents); compliance protocol was worse (61%); trials were suspended (60%); there was a lack of research staff (48%); and there were institutional closures (39%).

Regarding patient-related challenges, 67% of sites cited less willingness to visit the site. Other challenges included less ability to travel (cited by 60%), reduced access to the trial site (52%), quarantining because of exposure to COVID-19 (40%), and SARS-CoV-2 infection (26%).

Concerns of patients included the following: Fear of SARS-CoV-2 infection, which was cited by 83%; travel restrictions (47%); securing transportation (38%); and access to the laboratory/radiology services (14%).

“Patient willingness to visit the site was a consistent barrier reported across Europe, the U.S., and Canada,” said Dr. Smeltzer, although the effect was smaller in North America, he added.

Regarding mitigation strategies that were employed during the pandemic to combat the challenges and concerns, the team found that the most common measure was the modification of monitoring requirements, used by 44% of sites.

This was followed by the use of telehealth visits (43% sites), the use of laboratories at non-study facilities ( 27%), and alterations to the number of required visits (25%).

Other mitigation strategies included use of mail-order medications, (24%), using radiology services at a non-study site (20%), and altering the trial schedules (19%).

The most effective mitigation strategies were felt to be those that allowed flexibility with respect to location. These measures included use of remote monitoring, remote diagnostics, telehealth visits, and modified symptom monitoring.

Effective strategies that increased flexibility in time were delayed visits, delayed assessments, and changes to the Institutional Review Board.

The study was funded by the IASLC, which received industry support to conduct the project. Dr. Smeltzer reported no relevant financial relationships. Dr. Garassino has relationships with AstraZeneca, BMS, Boehringer Ingelheim, Celgene, Daiichi Sankyo, Eli Lilly, Ignyta, Incyte, MedImmune, Mirati, MSD International, Novartis, Pfizer, Regeneron, Roche, Takeda, and Seattle Genetics.

A version of this article first appeared on Medscape.com.

Although enrollment into lung cancer clinical trials fell during the early months of the COVID-19 pandemic, it increased after a number of mitigation strategies were introduced.

These strategies should now be maintained, say experts, in order to improve enrollment and access to trials and to ensure that trials are more pragmatic and streamlined.

These were the findings from a survey sent to 173 sites of clinical trials in 45 countries around the world. The findings were presented recently at the World Conference on Lung Cancer (WCLC) 2021. The meeting and the survey were organized by the International Association for the Study of Lung Cancer (IASLC).

Responses to the survey revealed that enrollment into lung cancer trials fell by 43% during the early months of the pandemic. Patients stopped attending clinics, and some trials were suspended.

Patients were less willing to visit clinical trial sites, and lockdown restrictions made travel difficult.

Organizers of clinical trials responded by implementing mitigation strategies, such as changing monitoring requirements, increasing use of telehealth, and using local non-study facilities for laboratory and radiology services.

These measures led to an increase in trial enrollment toward the end of 2020, the survey results show.

“The COVID-19 pandemic created many challenges [that led to] reductions in lung cancer clinical trial enrollment,” commented study presenter Matthew P. Smeltzer, PhD, from the Division of Epidemiology, Biostatistics, and Environmental Health, University of Memphis.

The employment of mitigation strategies allowed the removal of “barriers,” and although the pandemic “worsened, trial enrollment began to improve due in part to these strategies,” Dr. Smeltzer said.

Many of these measures were successful and should be maintained, he suggested. Strategies include allowing telehealth visits, performing testing at local laboratories, using local radiology services, mailing experimental agents “where possible,” and allowing flexibility in trial schedules.

This is a “very important” study, commented Marina Garassino, MD, professor of medicine, hematology, and oncology, the University of Chicago Medicine, in her discussion of the abstract.

Irrespective of the pandemic, the regulation and the bureaucracy of clinical trials hinder participation by patients and physicians, she said.

Many of the mitigation strategies highlighted by the survey were similar to recommendations on the conduct of clinical trials published by the American Society of Clinical Oncology during the pandemic. Those recommendations emphasize the use of telehealth and offsite strategies to help with patient monitoring, she noted.

The findings from the survey show that it is possible to conduct more “streamlined and pragmatic trials,” she said.

“More flexible approaches should be approved by the sponsors of clinical trials and global regulatory bodies,” she added.

However, she expressed concern that “with the telehealth visits, we can create some disparities.”

“We have to remember that lung cancer patients are sometimes a very old population, and they are not digitally evolved,” she commented.

Commenting on Twitter, Jennifer C. King, PhD, chief scientific officer at the GO2 Foundation for Lung Cancer, in Washington, D.C., agreed that many of the mitigation strategies identified in the study “are good for patients all of the time, not just during a pandemic.”

Impact on lung cancer clinical trials

The survey, which included 64 questions, was intended to assess the impact of the COVID pandemic on lung cancer clinical trials.

Most of the survey responses came from sites in Europe (37.6%); 21.4% came from Asia, 13.3% came from the United States, and 7.5% came from Canada.

The team found that enrollment into lung cancer trials declined by 43% in 2020 compared to 2019, at an incidence rate ratio of 0.57 (P = .0115).

The largest decreases in enrollment were between April and August 2020, Dr. Smeltzer noted. However, in the last quarter of 2020 (October to December), the differences in enrollment were significantly smaller (P = .0160), despite a marked increase in global COVID-19 cases per month, he added.

The most common challenges faced by clinical trial sites during the pandemic were the following: There were fewer eligible patients (cited by 67% of respondents); compliance protocol was worse (61%); trials were suspended (60%); there was a lack of research staff (48%); and there were institutional closures (39%).

Regarding patient-related challenges, 67% of sites cited less willingness to visit the site. Other challenges included less ability to travel (cited by 60%), reduced access to the trial site (52%), quarantining because of exposure to COVID-19 (40%), and SARS-CoV-2 infection (26%).

Concerns of patients included the following: Fear of SARS-CoV-2 infection, which was cited by 83%; travel restrictions (47%); securing transportation (38%); and access to the laboratory/radiology services (14%).

“Patient willingness to visit the site was a consistent barrier reported across Europe, the U.S., and Canada,” said Dr. Smeltzer, although the effect was smaller in North America, he added.

Regarding mitigation strategies that were employed during the pandemic to combat the challenges and concerns, the team found that the most common measure was the modification of monitoring requirements, used by 44% of sites.

This was followed by the use of telehealth visits (43% sites), the use of laboratories at non-study facilities ( 27%), and alterations to the number of required visits (25%).

Other mitigation strategies included use of mail-order medications, (24%), using radiology services at a non-study site (20%), and altering the trial schedules (19%).

The most effective mitigation strategies were felt to be those that allowed flexibility with respect to location. These measures included use of remote monitoring, remote diagnostics, telehealth visits, and modified symptom monitoring.

Effective strategies that increased flexibility in time were delayed visits, delayed assessments, and changes to the Institutional Review Board.

The study was funded by the IASLC, which received industry support to conduct the project. Dr. Smeltzer reported no relevant financial relationships. Dr. Garassino has relationships with AstraZeneca, BMS, Boehringer Ingelheim, Celgene, Daiichi Sankyo, Eli Lilly, Ignyta, Incyte, MedImmune, Mirati, MSD International, Novartis, Pfizer, Regeneron, Roche, Takeda, and Seattle Genetics.

A version of this article first appeared on Medscape.com.

Although enrollment into lung cancer clinical trials fell during the early months of the COVID-19 pandemic, it increased after a number of mitigation strategies were introduced.

These strategies should now be maintained, say experts, in order to improve enrollment and access to trials and to ensure that trials are more pragmatic and streamlined.

These were the findings from a survey sent to 173 sites of clinical trials in 45 countries around the world. The findings were presented recently at the World Conference on Lung Cancer (WCLC) 2021. The meeting and the survey were organized by the International Association for the Study of Lung Cancer (IASLC).

Responses to the survey revealed that enrollment into lung cancer trials fell by 43% during the early months of the pandemic. Patients stopped attending clinics, and some trials were suspended.

Patients were less willing to visit clinical trial sites, and lockdown restrictions made travel difficult.

Organizers of clinical trials responded by implementing mitigation strategies, such as changing monitoring requirements, increasing use of telehealth, and using local non-study facilities for laboratory and radiology services.

These measures led to an increase in trial enrollment toward the end of 2020, the survey results show.

“The COVID-19 pandemic created many challenges [that led to] reductions in lung cancer clinical trial enrollment,” commented study presenter Matthew P. Smeltzer, PhD, from the Division of Epidemiology, Biostatistics, and Environmental Health, University of Memphis.

The employment of mitigation strategies allowed the removal of “barriers,” and although the pandemic “worsened, trial enrollment began to improve due in part to these strategies,” Dr. Smeltzer said.

Many of these measures were successful and should be maintained, he suggested. Strategies include allowing telehealth visits, performing testing at local laboratories, using local radiology services, mailing experimental agents “where possible,” and allowing flexibility in trial schedules.

This is a “very important” study, commented Marina Garassino, MD, professor of medicine, hematology, and oncology, the University of Chicago Medicine, in her discussion of the abstract.

Irrespective of the pandemic, the regulation and the bureaucracy of clinical trials hinder participation by patients and physicians, she said.

Many of the mitigation strategies highlighted by the survey were similar to recommendations on the conduct of clinical trials published by the American Society of Clinical Oncology during the pandemic. Those recommendations emphasize the use of telehealth and offsite strategies to help with patient monitoring, she noted.

The findings from the survey show that it is possible to conduct more “streamlined and pragmatic trials,” she said.

“More flexible approaches should be approved by the sponsors of clinical trials and global regulatory bodies,” she added.

However, she expressed concern that “with the telehealth visits, we can create some disparities.”

“We have to remember that lung cancer patients are sometimes a very old population, and they are not digitally evolved,” she commented.

Commenting on Twitter, Jennifer C. King, PhD, chief scientific officer at the GO2 Foundation for Lung Cancer, in Washington, D.C., agreed that many of the mitigation strategies identified in the study “are good for patients all of the time, not just during a pandemic.”

Impact on lung cancer clinical trials

The survey, which included 64 questions, was intended to assess the impact of the COVID pandemic on lung cancer clinical trials.

Most of the survey responses came from sites in Europe (37.6%); 21.4% came from Asia, 13.3% came from the United States, and 7.5% came from Canada.

The team found that enrollment into lung cancer trials declined by 43% in 2020 compared to 2019, at an incidence rate ratio of 0.57 (P = .0115).

The largest decreases in enrollment were between April and August 2020, Dr. Smeltzer noted. However, in the last quarter of 2020 (October to December), the differences in enrollment were significantly smaller (P = .0160), despite a marked increase in global COVID-19 cases per month, he added.

The most common challenges faced by clinical trial sites during the pandemic were the following: There were fewer eligible patients (cited by 67% of respondents); compliance protocol was worse (61%); trials were suspended (60%); there was a lack of research staff (48%); and there were institutional closures (39%).

Regarding patient-related challenges, 67% of sites cited less willingness to visit the site. Other challenges included less ability to travel (cited by 60%), reduced access to the trial site (52%), quarantining because of exposure to COVID-19 (40%), and SARS-CoV-2 infection (26%).

Concerns of patients included the following: Fear of SARS-CoV-2 infection, which was cited by 83%; travel restrictions (47%); securing transportation (38%); and access to the laboratory/radiology services (14%).

“Patient willingness to visit the site was a consistent barrier reported across Europe, the U.S., and Canada,” said Dr. Smeltzer, although the effect was smaller in North America, he added.

Regarding mitigation strategies that were employed during the pandemic to combat the challenges and concerns, the team found that the most common measure was the modification of monitoring requirements, used by 44% of sites.

This was followed by the use of telehealth visits (43% sites), the use of laboratories at non-study facilities ( 27%), and alterations to the number of required visits (25%).

Other mitigation strategies included use of mail-order medications, (24%), using radiology services at a non-study site (20%), and altering the trial schedules (19%).

The most effective mitigation strategies were felt to be those that allowed flexibility with respect to location. These measures included use of remote monitoring, remote diagnostics, telehealth visits, and modified symptom monitoring.

Effective strategies that increased flexibility in time were delayed visits, delayed assessments, and changes to the Institutional Review Board.

The study was funded by the IASLC, which received industry support to conduct the project. Dr. Smeltzer reported no relevant financial relationships. Dr. Garassino has relationships with AstraZeneca, BMS, Boehringer Ingelheim, Celgene, Daiichi Sankyo, Eli Lilly, Ignyta, Incyte, MedImmune, Mirati, MSD International, Novartis, Pfizer, Regeneron, Roche, Takeda, and Seattle Genetics.

A version of this article first appeared on Medscape.com.

Air pollution is the second-leading cause of lung cancer in the world, after smoking, results of a novel analysis suggest. The researchers call for concerted action.

Ja&#039;Crispy/iStock/Getty Images Plus

The new data show that the rate of lung cancer deaths attributable to air pollution varies widely between countries. Serbia, Poland, China, Mongolia, and Turkey are among the worst affected. The analysis shows an association between deaths from lung cancer and the proportion of national energy that is produced from coal.

“Both smoking and air pollution are important causes of lung cancer,” said study presenter Christine D. Berg, MD, former codirector of the National Lung Screening Trial, and “both need to be eliminated to help prevent lung cancer and save lives.

“As lung cancer professionals, we can mitigate the effects of air pollution on causing lung cancer by speaking out for clean energy standards,” she said.

Dr. Berg presented the new analysis on Sept. 9 at the 2021 World Conference on Lung Cancer, which was organized by the International Association for the Study of Lung Cancer.

She welcomed the recent statement issued by the IASLC in support of the International Day of Clean Air for Blue Skies, which took place on Sept. 7. It was a call for action that emphasized the need for further efforts to improve air quality to protect human health.

The findings from the new analysis are “depressing,” commented Joachim G. J. V. Aerts, MD. PhD, department of pulmonary diseases, Erasmus University Medical Center, Rotterdam, the Netherlands.

It is now clear that air pollution has an impact not only on the incidence of lung cancer but also on its outcome, he added.

Indeed, previous research showed that each 10 mcg/m3 increase in particular matter of 2.5 mcg in size was associated with a 15%-27% increase in lung cancer mortality. There was no difference in rates between women and men.

A key question, Dr. Aerts said, is whether reducing air pollution would be beneficial.

Efforts to reduce air pollution over recent decades in the United Kingdom have not led to a reduction in lung cancer deaths. This is because of the increase in life expectancy – individuals have been exposed to pollution for longer, albeit at lower levels, he pointed out.

Because of lockdowns during the COVID pandemic, travel has been greatly reduced. This has resulted in a dramatic reduction in air pollution, “and this led to a decrease in the number of children born with low birth weight,” said Dr. Aerts.

Hopefully, that benefit will also be seen regarding other diseases, he added.

The call to action to reduce air pollution is of the “utmost importance,” he said. He noted that the focus should be on global, national, local, and personal preventive measures.

“It is time to join forces,” he added, “to ‘clean the air.’ ”

Dr. Berg’s presentation was warmly received on social media.

It was “fabulous,” commented Eric H. Bernicker, MD, director of medical thoracic oncology at Houston Methodist Cancer Center.

“Thoracic oncologists need to add air pollution to things they advocate about; we have an important voice here,” he added.

It is “so important to understand that air pollution is a human carcinogen,” commented Ivy Elkins, a lung cancer survivor and advocate and cofounder of the EGFR Resisters Lung Cancer Patient Group. “All you need are lungs to get lung cancer!”
 

Contribution of air pollution to lung cancer

In her presentation, Dr. Berg emphasized that lung cancer is the leading cause of cancer death worldwide, although the distribution between countries “depends on historical and current smoking patterns and the demographics of the population.”

Overall, data from GLOBOCAN 2018 indicate that annually there are approximately 2.1 million incident cases of lung cancer and almost 1.8 million lung cancer deaths around the globe.

A recent study estimated that, worldwide, 14.1% of all lung cancer deaths, including in never-smokers, are directly linked to air pollution.

Dr. Berg said that this makes it the “second-leading cause of lung cancer” behind smoking.

The figure is somewhat lower for the United States, where around 4.7% of lung cancer deaths each year are directly attributable to pollution. However, with “the wildfires out West, we’re going to be seeing more of a toll from air pollution,” she predicted.

She pointed out that the International Agency for Research on Cancer classifies outdoor air pollution, especially particulate matter, as a human carcinogen on the basis of evidence of an association with lung cancer.

It is thought that direct deposits and local effects of particulate matter lead to oxidative damage and low-grade chronic inflammation. These in turn result in molecular changes that affect DNA and gene transcription and inhibit apoptosis, all of which lead to the development of cancerous lesions, she explained.

Synthesizing various estimates on global burden of disease, Dr. Berg and colleagues calculated that in 2019 the rate of lung cancer deaths attributable to particular matter in people aged 50-69 years was highest in Serbia, at 36.88 attributable deaths per 100,000.

Next was Poland, with a rate of 27.97 per 100,000, followed by China at 24.63 per 100,000, Mongolia at 19.71 per 100,000, and Turkey at 19.2 per 100,000.

The major sources of air pollution in the most affected countries were transportation, indoor cooking, and energy sources, she said.

In Serbia, 70% of energy production was from coal. It was 74% in Poland, 65% in China, 80% in Mongolia, 35% in Turkey, and 19% in the United States.

At the time of the analysis, only 17.3% of U.S. adults were smokers, and the air concentration of particular matter of 2.5 mcm was 9.6% mcg/m³. Both of these rates are far below those seen in more severely affected countries.

“But 40% of our energy now comes from natural gas,” noted Dr. Berg, “which is still a pollutant and a source of methane. It’s a very potent greenhouse gas.”

No funding for the study has been reported. Dr. Berg has relationships with GRAIL and Mercy BioAnalytics. Dr. Aerts has relationships with Amphera, AstraZeneca, Bayer, BIOCAD, Bristol-Myers Squibb, Eli Lilly, and Roche.

A version of this article first appeared on Medscape.com.

Air pollution is the second-leading cause of lung cancer in the world, after smoking, results of a novel analysis suggest. The researchers call for concerted action.

Ja&#039;Crispy/iStock/Getty Images Plus

The new data show that the rate of lung cancer deaths attributable to air pollution varies widely between countries. Serbia, Poland, China, Mongolia, and Turkey are among the worst affected. The analysis shows an association between deaths from lung cancer and the proportion of national energy that is produced from coal.

“Both smoking and air pollution are important causes of lung cancer,” said study presenter Christine D. Berg, MD, former codirector of the National Lung Screening Trial, and “both need to be eliminated to help prevent lung cancer and save lives.

“As lung cancer professionals, we can mitigate the effects of air pollution on causing lung cancer by speaking out for clean energy standards,” she said.

Dr. Berg presented the new analysis on Sept. 9 at the 2021 World Conference on Lung Cancer, which was organized by the International Association for the Study of Lung Cancer.

She welcomed the recent statement issued by the IASLC in support of the International Day of Clean Air for Blue Skies, which took place on Sept. 7. It was a call for action that emphasized the need for further efforts to improve air quality to protect human health.

The findings from the new analysis are “depressing,” commented Joachim G. J. V. Aerts, MD. PhD, department of pulmonary diseases, Erasmus University Medical Center, Rotterdam, the Netherlands.

It is now clear that air pollution has an impact not only on the incidence of lung cancer but also on its outcome, he added.

Indeed, previous research showed that each 10 mcg/m3 increase in particular matter of 2.5 mcg in size was associated with a 15%-27% increase in lung cancer mortality. There was no difference in rates between women and men.

A key question, Dr. Aerts said, is whether reducing air pollution would be beneficial.

Efforts to reduce air pollution over recent decades in the United Kingdom have not led to a reduction in lung cancer deaths. This is because of the increase in life expectancy – individuals have been exposed to pollution for longer, albeit at lower levels, he pointed out.

Because of lockdowns during the COVID pandemic, travel has been greatly reduced. This has resulted in a dramatic reduction in air pollution, “and this led to a decrease in the number of children born with low birth weight,” said Dr. Aerts.

Hopefully, that benefit will also be seen regarding other diseases, he added.

The call to action to reduce air pollution is of the “utmost importance,” he said. He noted that the focus should be on global, national, local, and personal preventive measures.

“It is time to join forces,” he added, “to ‘clean the air.’ ”

Dr. Berg’s presentation was warmly received on social media.

It was “fabulous,” commented Eric H. Bernicker, MD, director of medical thoracic oncology at Houston Methodist Cancer Center.

“Thoracic oncologists need to add air pollution to things they advocate about; we have an important voice here,” he added.

It is “so important to understand that air pollution is a human carcinogen,” commented Ivy Elkins, a lung cancer survivor and advocate and cofounder of the EGFR Resisters Lung Cancer Patient Group. “All you need are lungs to get lung cancer!”
 

Contribution of air pollution to lung cancer

In her presentation, Dr. Berg emphasized that lung cancer is the leading cause of cancer death worldwide, although the distribution between countries “depends on historical and current smoking patterns and the demographics of the population.”

Overall, data from GLOBOCAN 2018 indicate that annually there are approximately 2.1 million incident cases of lung cancer and almost 1.8 million lung cancer deaths around the globe.

A recent study estimated that, worldwide, 14.1% of all lung cancer deaths, including in never-smokers, are directly linked to air pollution.

Dr. Berg said that this makes it the “second-leading cause of lung cancer” behind smoking.

The figure is somewhat lower for the United States, where around 4.7% of lung cancer deaths each year are directly attributable to pollution. However, with “the wildfires out West, we’re going to be seeing more of a toll from air pollution,” she predicted.

She pointed out that the International Agency for Research on Cancer classifies outdoor air pollution, especially particulate matter, as a human carcinogen on the basis of evidence of an association with lung cancer.

It is thought that direct deposits and local effects of particulate matter lead to oxidative damage and low-grade chronic inflammation. These in turn result in molecular changes that affect DNA and gene transcription and inhibit apoptosis, all of which lead to the development of cancerous lesions, she explained.

Synthesizing various estimates on global burden of disease, Dr. Berg and colleagues calculated that in 2019 the rate of lung cancer deaths attributable to particular matter in people aged 50-69 years was highest in Serbia, at 36.88 attributable deaths per 100,000.

Next was Poland, with a rate of 27.97 per 100,000, followed by China at 24.63 per 100,000, Mongolia at 19.71 per 100,000, and Turkey at 19.2 per 100,000.

The major sources of air pollution in the most affected countries were transportation, indoor cooking, and energy sources, she said.

In Serbia, 70% of energy production was from coal. It was 74% in Poland, 65% in China, 80% in Mongolia, 35% in Turkey, and 19% in the United States.

At the time of the analysis, only 17.3% of U.S. adults were smokers, and the air concentration of particular matter of 2.5 mcm was 9.6% mcg/m³. Both of these rates are far below those seen in more severely affected countries.

“But 40% of our energy now comes from natural gas,” noted Dr. Berg, “which is still a pollutant and a source of methane. It’s a very potent greenhouse gas.”

No funding for the study has been reported. Dr. Berg has relationships with GRAIL and Mercy BioAnalytics. Dr. Aerts has relationships with Amphera, AstraZeneca, Bayer, BIOCAD, Bristol-Myers Squibb, Eli Lilly, and Roche.

A version of this article first appeared on Medscape.com.

Air pollution is the second-leading cause of lung cancer in the world, after smoking, results of a novel analysis suggest. The researchers call for concerted action.

Ja&#039;Crispy/iStock/Getty Images Plus

The new data show that the rate of lung cancer deaths attributable to air pollution varies widely between countries. Serbia, Poland, China, Mongolia, and Turkey are among the worst affected. The analysis shows an association between deaths from lung cancer and the proportion of national energy that is produced from coal.

“Both smoking and air pollution are important causes of lung cancer,” said study presenter Christine D. Berg, MD, former codirector of the National Lung Screening Trial, and “both need to be eliminated to help prevent lung cancer and save lives.

“As lung cancer professionals, we can mitigate the effects of air pollution on causing lung cancer by speaking out for clean energy standards,” she said.

Dr. Berg presented the new analysis on Sept. 9 at the 2021 World Conference on Lung Cancer, which was organized by the International Association for the Study of Lung Cancer.

She welcomed the recent statement issued by the IASLC in support of the International Day of Clean Air for Blue Skies, which took place on Sept. 7. It was a call for action that emphasized the need for further efforts to improve air quality to protect human health.

The findings from the new analysis are “depressing,” commented Joachim G. J. V. Aerts, MD. PhD, department of pulmonary diseases, Erasmus University Medical Center, Rotterdam, the Netherlands.

It is now clear that air pollution has an impact not only on the incidence of lung cancer but also on its outcome, he added.

Indeed, previous research showed that each 10 mcg/m3 increase in particular matter of 2.5 mcg in size was associated with a 15%-27% increase in lung cancer mortality. There was no difference in rates between women and men.

A key question, Dr. Aerts said, is whether reducing air pollution would be beneficial.

Efforts to reduce air pollution over recent decades in the United Kingdom have not led to a reduction in lung cancer deaths. This is because of the increase in life expectancy – individuals have been exposed to pollution for longer, albeit at lower levels, he pointed out.

Because of lockdowns during the COVID pandemic, travel has been greatly reduced. This has resulted in a dramatic reduction in air pollution, “and this led to a decrease in the number of children born with low birth weight,” said Dr. Aerts.

Hopefully, that benefit will also be seen regarding other diseases, he added.

The call to action to reduce air pollution is of the “utmost importance,” he said. He noted that the focus should be on global, national, local, and personal preventive measures.

“It is time to join forces,” he added, “to ‘clean the air.’ ”

Dr. Berg’s presentation was warmly received on social media.

It was “fabulous,” commented Eric H. Bernicker, MD, director of medical thoracic oncology at Houston Methodist Cancer Center.

“Thoracic oncologists need to add air pollution to things they advocate about; we have an important voice here,” he added.

It is “so important to understand that air pollution is a human carcinogen,” commented Ivy Elkins, a lung cancer survivor and advocate and cofounder of the EGFR Resisters Lung Cancer Patient Group. “All you need are lungs to get lung cancer!”
 

Contribution of air pollution to lung cancer

In her presentation, Dr. Berg emphasized that lung cancer is the leading cause of cancer death worldwide, although the distribution between countries “depends on historical and current smoking patterns and the demographics of the population.”

Overall, data from GLOBOCAN 2018 indicate that annually there are approximately 2.1 million incident cases of lung cancer and almost 1.8 million lung cancer deaths around the globe.

A recent study estimated that, worldwide, 14.1% of all lung cancer deaths, including in never-smokers, are directly linked to air pollution.

Dr. Berg said that this makes it the “second-leading cause of lung cancer” behind smoking.

The figure is somewhat lower for the United States, where around 4.7% of lung cancer deaths each year are directly attributable to pollution. However, with “the wildfires out West, we’re going to be seeing more of a toll from air pollution,” she predicted.

She pointed out that the International Agency for Research on Cancer classifies outdoor air pollution, especially particulate matter, as a human carcinogen on the basis of evidence of an association with lung cancer.

It is thought that direct deposits and local effects of particulate matter lead to oxidative damage and low-grade chronic inflammation. These in turn result in molecular changes that affect DNA and gene transcription and inhibit apoptosis, all of which lead to the development of cancerous lesions, she explained.

Synthesizing various estimates on global burden of disease, Dr. Berg and colleagues calculated that in 2019 the rate of lung cancer deaths attributable to particular matter in people aged 50-69 years was highest in Serbia, at 36.88 attributable deaths per 100,000.

Next was Poland, with a rate of 27.97 per 100,000, followed by China at 24.63 per 100,000, Mongolia at 19.71 per 100,000, and Turkey at 19.2 per 100,000.

The major sources of air pollution in the most affected countries were transportation, indoor cooking, and energy sources, she said.

In Serbia, 70% of energy production was from coal. It was 74% in Poland, 65% in China, 80% in Mongolia, 35% in Turkey, and 19% in the United States.

At the time of the analysis, only 17.3% of U.S. adults were smokers, and the air concentration of particular matter of 2.5 mcm was 9.6% mcg/m³. Both of these rates are far below those seen in more severely affected countries.

“But 40% of our energy now comes from natural gas,” noted Dr. Berg, “which is still a pollutant and a source of methane. It’s a very potent greenhouse gas.”

No funding for the study has been reported. Dr. Berg has relationships with GRAIL and Mercy BioAnalytics. Dr. Aerts has relationships with Amphera, AstraZeneca, Bayer, BIOCAD, Bristol-Myers Squibb, Eli Lilly, and Roche.

A version of this article first appeared on Medscape.com.

Overall cancer risk is slightly increased in patients older than 40 years within their first year of a celiac disease diagnosis, but the risk drops within a year of diagnosis, shows a Swedish study of 47,000 people with celiac disease.

“Celiac disease is associated with an increased risk of types of cancer, and we believe that this is due to the longstanding inflammation that is induced by gluten,” said first author Benjamin Lebwohl, MD, director of clinical research at the Columbia University Celiac Disease Center in New York.

Writing in Clinical Gastroenterology and Hepatology, the authors explained that most studies investigating cancer risk in patients with celiac disease were done before both the widespread use of serologic testing for celiac disease and access to gluten-free food was widely available. Earlier studies linked celiac disease to gastrointestinal malignancies, such as small intestinal adenocarcinoma, and lymphomas.

A prior analysis of this Swedish cohort found that the risk of small intestinal adenocarcinoma, while low, continued for up to 10 years after diagnosis with celiac disease. In the study, which was published in Gastroenterology, the authors found the risks of small-bowel adenocarcinoma and adenomas were significantly increased in people with celiac disease, compared with those without this disease.

“We have known from prior studies that people with celiac disease are at increased risk of developing certain cancers, but there has been limited study of this risk in celiac disease in the 21st century, where there is increased recognition (leading to more prompt diagnosis) and increased access to gluten-free food options (which may allow for more effective treatment),” said Dr. Lebwohl, who is also the director of quality improvement in the division of digestive and liver diseases at Columbia University. “We aimed to determine whether there is still an increased risk of cancer in this modern era, and we found that there still is an increased risk, but this increase is small and that it diminishes beyond the first year after the diagnosis of celiac disease.”

This nationwide cohort study in Sweden included 47,241 patients with celiac disease (62% female; mean age, 24 years), of which 64% were diagnosed since 2000. Each patient was age and sex matched to up to five controls. After a median follow-up of 11.5 years, a 1.11-fold increased risk of cancer overall was found in patients with celiac disease, compared with controls. The respective incidences of cancer were 6.5 and 5.7 per 1,000 person-years, and most of the excess risk was caused by gastrointestinal and hematologic cancer.

The overall risk of cancer was increased in the first year after celiac disease diagnosis (HR, 2.47; 95% CI, 2.22-2.74) but not afterwards (HR, 1.01; 95% CI, 0.97-1.05).

“It appears that the increased risk of cancer in people with celiac disease decreased over time, and this may be related to the beneficial effect of the gluten-free diet in the long term,” Dr. Lebwohl said.

The authors suggest that cancer risk, followed by a decline to no risk, may alternatively be due to the increased monitoring and medical examinations among patients with celiac disease. Also, symptoms of cancer, such as weight loss, may lead to broad testing that identifies celiac disease, the authors wrote.

For cancer subtypes, the strongest association between celiac disease and cancer was found for hematologic, lymphoproliferative and gastrointestinal cancers. Among gastrointestinal cancer subtypes, elevated risks were found for hepatobiliary and pancreatic cancer, but not for gastric or colorectal cancer. The cancer risk in celiac disease decreased in breast and lung cancer, which the authors suggested may be attributed to lower body mass index and smoking rates, respectively, observed in individuals with celiac disease.
 

Certain cancer types persist after 1 year

Although there was no overall cancer risk for more than 1 year after celiac disease diagnosis, the risks of hematologic and lymphoproliferative cancers persisted. While the increased risk of gastrointestinal cancers collectively was no longer significant beyond 1 year after celiac disease diagnosis, the risk persisted for hepatobiliary and pancreatic cancer.

“We found that the risk of gastrointestinal cancers is increased in people with celiac disease, compared to the general population, but these risks vary according to the cancer type,” Dr. Lebwohl said. “For instance, the risk of pancreatic cancer is increased in people with celiac disease, compared to the general population, while the risk of colon cancer in people with celiac disease is not increased, compared to the general population.

“But pancreatic cancer is far less common than colon cancer. We found that pancreatic cancer occurs in 1 in 5,000 people with celiac disease per year, whereas colorectal cancer occurred in 1 in 1,400 people per year. Taken all together, the risk of any gastrointestinal cancer was around 1 in 700 per year among people with celiac disease,” Dr. Lebwohl said.

The overall cancer risk was highest in patients diagnosed with celiac disease after age 60 and was not increased in those diagnosed with celiac disease before age 40. The authors noted that, in recent years, there has been a pronounced increase in the diagnosis of celiac disease in people aged over 60, an age group with a higher risk of developing severe outcomes related to refractory celiac disease. The cancer risk was similar among patients diagnosed with celiac disease before or after 2000.

Since this is an observational study, causality cannot be proven, and the authors suggested that the findings may not be applicable to settings outside of the relatively homogeneous ethnic population of Sweden.

Carol E. Semrad, MD, professor of medicine and director of clinical research in the Celiac Center at the University of Chicago Medicine, said: “This is an observational study and therefore cannot answer whether celiac disease is the cause of cancer or merely an association.” She added that “it is unknown why the risk for some cancers is higher in celiac disease.

“This paper argues against delayed diagnosis and low detection rate to explain the increase in cancer risk as those diagnosed with celiac disease prior to 2000 had the same cancer risk as those diagnosed after 2000 when diagnostic testing, earlier diagnosis, and access to a gluten-free diet were better,” Dr. Semrad said.
 

Link to mortality data

The authors said increased cancer risk being restricted to the first year of diagnosis is consistent with prior celiac disease studies of morbidity and mortality.

A study published in 2019 in United European Gastroenterology looked at mortality risk in 602 patients with celiac disease from Lothian, Scotland, identified between 1979 and 1983 and followed up from 1970 to 2016. All-cause mortality was 43% higher than in the general population, mainly from hematologic malignancies, and this risk was greatest during the first few years of diagnosis.

An analysis of cause-specific mortality in the Swedish cohort, published in 2020 in JAMA, found that celiac disease was associated with a small but statistically significant increased mortality risk. After a median follow-up of 12.5 years of 49,829 patients with celiac disease, the mortality rate was 9.7 and 8.6 deaths per 1000 person-years, compared with the general population, respectively. Individuals with celiac disease were at increased risk of death from cancer, cardiovascular disease and respiratory disease. The overall mortality risk was greatest in the first year after diagnosis with celiac disease, after which the risk diminished with the establishment of the gluten-free diet but remained modestly elevated in the long term.

However, a Finnish population-based study, published in the American Journal of Gastroenterology, found no increase in overall mortality in patients with celiac disease. The study included 12,803 adults diagnosed with celiac disease between 2005 and 2014. Participants were followed for an average of 7.7 years and mortality from all malignancies, gastrointestinal tract malignancies or cardiovascular diseases were not increased among patients with celiac disease, compared with the general population. Mortality from lymphoproliferative diseases was increased in patients with celiac disease but was lower than previously reported.

Dr. Lebwohl and colleagues noted that the incidences of cancer types vary by the age and geographical region of the study population, as does the diagnosis of celiac disease, which may explain why increased risk for cancer or cancer related-mortality in patients with celiac disease has not always been reported.

Dr Ludvigsson coordinates a study on behalf of the Swedish IBD quality register. This study has received funding from Janssen. The remaining authors disclosed no conflicts.

Overall cancer risk is slightly increased in patients older than 40 years within their first year of a celiac disease diagnosis, but the risk drops within a year of diagnosis, shows a Swedish study of 47,000 people with celiac disease.

“Celiac disease is associated with an increased risk of types of cancer, and we believe that this is due to the longstanding inflammation that is induced by gluten,” said first author Benjamin Lebwohl, MD, director of clinical research at the Columbia University Celiac Disease Center in New York.

Writing in Clinical Gastroenterology and Hepatology, the authors explained that most studies investigating cancer risk in patients with celiac disease were done before both the widespread use of serologic testing for celiac disease and access to gluten-free food was widely available. Earlier studies linked celiac disease to gastrointestinal malignancies, such as small intestinal adenocarcinoma, and lymphomas.

A prior analysis of this Swedish cohort found that the risk of small intestinal adenocarcinoma, while low, continued for up to 10 years after diagnosis with celiac disease. In the study, which was published in Gastroenterology, the authors found the risks of small-bowel adenocarcinoma and adenomas were significantly increased in people with celiac disease, compared with those without this disease.

“We have known from prior studies that people with celiac disease are at increased risk of developing certain cancers, but there has been limited study of this risk in celiac disease in the 21st century, where there is increased recognition (leading to more prompt diagnosis) and increased access to gluten-free food options (which may allow for more effective treatment),” said Dr. Lebwohl, who is also the director of quality improvement in the division of digestive and liver diseases at Columbia University. “We aimed to determine whether there is still an increased risk of cancer in this modern era, and we found that there still is an increased risk, but this increase is small and that it diminishes beyond the first year after the diagnosis of celiac disease.”

This nationwide cohort study in Sweden included 47,241 patients with celiac disease (62% female; mean age, 24 years), of which 64% were diagnosed since 2000. Each patient was age and sex matched to up to five controls. After a median follow-up of 11.5 years, a 1.11-fold increased risk of cancer overall was found in patients with celiac disease, compared with controls. The respective incidences of cancer were 6.5 and 5.7 per 1,000 person-years, and most of the excess risk was caused by gastrointestinal and hematologic cancer.

The overall risk of cancer was increased in the first year after celiac disease diagnosis (HR, 2.47; 95% CI, 2.22-2.74) but not afterwards (HR, 1.01; 95% CI, 0.97-1.05).

“It appears that the increased risk of cancer in people with celiac disease decreased over time, and this may be related to the beneficial effect of the gluten-free diet in the long term,” Dr. Lebwohl said.

The authors suggest that cancer risk, followed by a decline to no risk, may alternatively be due to the increased monitoring and medical examinations among patients with celiac disease. Also, symptoms of cancer, such as weight loss, may lead to broad testing that identifies celiac disease, the authors wrote.

For cancer subtypes, the strongest association between celiac disease and cancer was found for hematologic, lymphoproliferative and gastrointestinal cancers. Among gastrointestinal cancer subtypes, elevated risks were found for hepatobiliary and pancreatic cancer, but not for gastric or colorectal cancer. The cancer risk in celiac disease decreased in breast and lung cancer, which the authors suggested may be attributed to lower body mass index and smoking rates, respectively, observed in individuals with celiac disease.
 

Certain cancer types persist after 1 year

Although there was no overall cancer risk for more than 1 year after celiac disease diagnosis, the risks of hematologic and lymphoproliferative cancers persisted. While the increased risk of gastrointestinal cancers collectively was no longer significant beyond 1 year after celiac disease diagnosis, the risk persisted for hepatobiliary and pancreatic cancer.

“We found that the risk of gastrointestinal cancers is increased in people with celiac disease, compared to the general population, but these risks vary according to the cancer type,” Dr. Lebwohl said. “For instance, the risk of pancreatic cancer is increased in people with celiac disease, compared to the general population, while the risk of colon cancer in people with celiac disease is not increased, compared to the general population.

“But pancreatic cancer is far less common than colon cancer. We found that pancreatic cancer occurs in 1 in 5,000 people with celiac disease per year, whereas colorectal cancer occurred in 1 in 1,400 people per year. Taken all together, the risk of any gastrointestinal cancer was around 1 in 700 per year among people with celiac disease,” Dr. Lebwohl said.

The overall cancer risk was highest in patients diagnosed with celiac disease after age 60 and was not increased in those diagnosed with celiac disease before age 40. The authors noted that, in recent years, there has been a pronounced increase in the diagnosis of celiac disease in people aged over 60, an age group with a higher risk of developing severe outcomes related to refractory celiac disease. The cancer risk was similar among patients diagnosed with celiac disease before or after 2000.

Since this is an observational study, causality cannot be proven, and the authors suggested that the findings may not be applicable to settings outside of the relatively homogeneous ethnic population of Sweden.

Carol E. Semrad, MD, professor of medicine and director of clinical research in the Celiac Center at the University of Chicago Medicine, said: “This is an observational study and therefore cannot answer whether celiac disease is the cause of cancer or merely an association.” She added that “it is unknown why the risk for some cancers is higher in celiac disease.

“This paper argues against delayed diagnosis and low detection rate to explain the increase in cancer risk as those diagnosed with celiac disease prior to 2000 had the same cancer risk as those diagnosed after 2000 when diagnostic testing, earlier diagnosis, and access to a gluten-free diet were better,” Dr. Semrad said.
 

Link to mortality data

The authors said increased cancer risk being restricted to the first year of diagnosis is consistent with prior celiac disease studies of morbidity and mortality.

A study published in 2019 in United European Gastroenterology looked at mortality risk in 602 patients with celiac disease from Lothian, Scotland, identified between 1979 and 1983 and followed up from 1970 to 2016. All-cause mortality was 43% higher than in the general population, mainly from hematologic malignancies, and this risk was greatest during the first few years of diagnosis.

An analysis of cause-specific mortality in the Swedish cohort, published in 2020 in JAMA, found that celiac disease was associated with a small but statistically significant increased mortality risk. After a median follow-up of 12.5 years of 49,829 patients with celiac disease, the mortality rate was 9.7 and 8.6 deaths per 1000 person-years, compared with the general population, respectively. Individuals with celiac disease were at increased risk of death from cancer, cardiovascular disease and respiratory disease. The overall mortality risk was greatest in the first year after diagnosis with celiac disease, after which the risk diminished with the establishment of the gluten-free diet but remained modestly elevated in the long term.

However, a Finnish population-based study, published in the American Journal of Gastroenterology, found no increase in overall mortality in patients with celiac disease. The study included 12,803 adults diagnosed with celiac disease between 2005 and 2014. Participants were followed for an average of 7.7 years and mortality from all malignancies, gastrointestinal tract malignancies or cardiovascular diseases were not increased among patients with celiac disease, compared with the general population. Mortality from lymphoproliferative diseases was increased in patients with celiac disease but was lower than previously reported.

Dr. Lebwohl and colleagues noted that the incidences of cancer types vary by the age and geographical region of the study population, as does the diagnosis of celiac disease, which may explain why increased risk for cancer or cancer related-mortality in patients with celiac disease has not always been reported.

Dr Ludvigsson coordinates a study on behalf of the Swedish IBD quality register. This study has received funding from Janssen. The remaining authors disclosed no conflicts.

Overall cancer risk is slightly increased in patients older than 40 years within their first year of a celiac disease diagnosis, but the risk drops within a year of diagnosis, shows a Swedish study of 47,000 people with celiac disease.

“Celiac disease is associated with an increased risk of types of cancer, and we believe that this is due to the longstanding inflammation that is induced by gluten,” said first author Benjamin Lebwohl, MD, director of clinical research at the Columbia University Celiac Disease Center in New York.

Writing in Clinical Gastroenterology and Hepatology, the authors explained that most studies investigating cancer risk in patients with celiac disease were done before both the widespread use of serologic testing for celiac disease and access to gluten-free food was widely available. Earlier studies linked celiac disease to gastrointestinal malignancies, such as small intestinal adenocarcinoma, and lymphomas.

A prior analysis of this Swedish cohort found that the risk of small intestinal adenocarcinoma, while low, continued for up to 10 years after diagnosis with celiac disease. In the study, which was published in Gastroenterology, the authors found the risks of small-bowel adenocarcinoma and adenomas were significantly increased in people with celiac disease, compared with those without this disease.

“We have known from prior studies that people with celiac disease are at increased risk of developing certain cancers, but there has been limited study of this risk in celiac disease in the 21st century, where there is increased recognition (leading to more prompt diagnosis) and increased access to gluten-free food options (which may allow for more effective treatment),” said Dr. Lebwohl, who is also the director of quality improvement in the division of digestive and liver diseases at Columbia University. “We aimed to determine whether there is still an increased risk of cancer in this modern era, and we found that there still is an increased risk, but this increase is small and that it diminishes beyond the first year after the diagnosis of celiac disease.”

This nationwide cohort study in Sweden included 47,241 patients with celiac disease (62% female; mean age, 24 years), of which 64% were diagnosed since 2000. Each patient was age and sex matched to up to five controls. After a median follow-up of 11.5 years, a 1.11-fold increased risk of cancer overall was found in patients with celiac disease, compared with controls. The respective incidences of cancer were 6.5 and 5.7 per 1,000 person-years, and most of the excess risk was caused by gastrointestinal and hematologic cancer.

The overall risk of cancer was increased in the first year after celiac disease diagnosis (HR, 2.47; 95% CI, 2.22-2.74) but not afterwards (HR, 1.01; 95% CI, 0.97-1.05).

“It appears that the increased risk of cancer in people with celiac disease decreased over time, and this may be related to the beneficial effect of the gluten-free diet in the long term,” Dr. Lebwohl said.

The authors suggest that cancer risk, followed by a decline to no risk, may alternatively be due to the increased monitoring and medical examinations among patients with celiac disease. Also, symptoms of cancer, such as weight loss, may lead to broad testing that identifies celiac disease, the authors wrote.

For cancer subtypes, the strongest association between celiac disease and cancer was found for hematologic, lymphoproliferative and gastrointestinal cancers. Among gastrointestinal cancer subtypes, elevated risks were found for hepatobiliary and pancreatic cancer, but not for gastric or colorectal cancer. The cancer risk in celiac disease decreased in breast and lung cancer, which the authors suggested may be attributed to lower body mass index and smoking rates, respectively, observed in individuals with celiac disease.
 

Certain cancer types persist after 1 year

Although there was no overall cancer risk for more than 1 year after celiac disease diagnosis, the risks of hematologic and lymphoproliferative cancers persisted. While the increased risk of gastrointestinal cancers collectively was no longer significant beyond 1 year after celiac disease diagnosis, the risk persisted for hepatobiliary and pancreatic cancer.

“We found that the risk of gastrointestinal cancers is increased in people with celiac disease, compared to the general population, but these risks vary according to the cancer type,” Dr. Lebwohl said. “For instance, the risk of pancreatic cancer is increased in people with celiac disease, compared to the general population, while the risk of colon cancer in people with celiac disease is not increased, compared to the general population.

“But pancreatic cancer is far less common than colon cancer. We found that pancreatic cancer occurs in 1 in 5,000 people with celiac disease per year, whereas colorectal cancer occurred in 1 in 1,400 people per year. Taken all together, the risk of any gastrointestinal cancer was around 1 in 700 per year among people with celiac disease,” Dr. Lebwohl said.

The overall cancer risk was highest in patients diagnosed with celiac disease after age 60 and was not increased in those diagnosed with celiac disease before age 40. The authors noted that, in recent years, there has been a pronounced increase in the diagnosis of celiac disease in people aged over 60, an age group with a higher risk of developing severe outcomes related to refractory celiac disease. The cancer risk was similar among patients diagnosed with celiac disease before or after 2000.

Since this is an observational study, causality cannot be proven, and the authors suggested that the findings may not be applicable to settings outside of the relatively homogeneous ethnic population of Sweden.

Carol E. Semrad, MD, professor of medicine and director of clinical research in the Celiac Center at the University of Chicago Medicine, said: “This is an observational study and therefore cannot answer whether celiac disease is the cause of cancer or merely an association.” She added that “it is unknown why the risk for some cancers is higher in celiac disease.

“This paper argues against delayed diagnosis and low detection rate to explain the increase in cancer risk as those diagnosed with celiac disease prior to 2000 had the same cancer risk as those diagnosed after 2000 when diagnostic testing, earlier diagnosis, and access to a gluten-free diet were better,” Dr. Semrad said.
 

Link to mortality data

The authors said increased cancer risk being restricted to the first year of diagnosis is consistent with prior celiac disease studies of morbidity and mortality.

A study published in 2019 in United European Gastroenterology looked at mortality risk in 602 patients with celiac disease from Lothian, Scotland, identified between 1979 and 1983 and followed up from 1970 to 2016. All-cause mortality was 43% higher than in the general population, mainly from hematologic malignancies, and this risk was greatest during the first few years of diagnosis.

An analysis of cause-specific mortality in the Swedish cohort, published in 2020 in JAMA, found that celiac disease was associated with a small but statistically significant increased mortality risk. After a median follow-up of 12.5 years of 49,829 patients with celiac disease, the mortality rate was 9.7 and 8.6 deaths per 1000 person-years, compared with the general population, respectively. Individuals with celiac disease were at increased risk of death from cancer, cardiovascular disease and respiratory disease. The overall mortality risk was greatest in the first year after diagnosis with celiac disease, after which the risk diminished with the establishment of the gluten-free diet but remained modestly elevated in the long term.

However, a Finnish population-based study, published in the American Journal of Gastroenterology, found no increase in overall mortality in patients with celiac disease. The study included 12,803 adults diagnosed with celiac disease between 2005 and 2014. Participants were followed for an average of 7.7 years and mortality from all malignancies, gastrointestinal tract malignancies or cardiovascular diseases were not increased among patients with celiac disease, compared with the general population. Mortality from lymphoproliferative diseases was increased in patients with celiac disease but was lower than previously reported.

Dr. Lebwohl and colleagues noted that the incidences of cancer types vary by the age and geographical region of the study population, as does the diagnosis of celiac disease, which may explain why increased risk for cancer or cancer related-mortality in patients with celiac disease has not always been reported.

Dr Ludvigsson coordinates a study on behalf of the Swedish IBD quality register. This study has received funding from Janssen. The remaining authors disclosed no conflicts.