Zachary Lyons, MD

Breast cancer is the most common cancer in women and ranks second, after lung cancer, as a cause of cancer-related death in women.

In the United States alone, an estimated 231,840 women will be diagnosed with breast cancer in 2015. Largely as a result of screening mammography and early detection, associated mortality has been steadily declining since 1990. Still, the American Cancer Society has estimated that 40,290 U.S. women will die of breast cancer in 2015.

Specific recommendations for breast cancer screening vary significantly between two major guidelines: the U.S. Preventive Services Task Force (USPSTF) and the American Cancer Society (ACS). In 2003, the ACS recommended annual screening with mammography for women beginning at age 40, stopping only when a woman’s health would preclude her from cancer treatment. Furthermore, the ACS recommended a clinical breast examination (CBE) at least every 3 years for women in their 20s and 30s and then annually starting at age 40. Current USPSTF guidelines recommend mammograms biennially from age 50 to age 74, finding insufficient evidence to recommend CBE.

Gaps between these two organizations are shrinking, however, as the ACS released its new 2015 guidelines, updating the 2003 recommendations for breast cancer screening for women at average risk. The ACS defined average risk broadly: women without a personal history of breast cancer, a confirmed or suspected genetic mutation known to increase risk of breast cancer (e.g., BRCA), or a history of previous radiotherapy to the chest at a young age. These guidelines include the following recommendations:

1. Women with an average risk of breast cancer should undergo regular screening mammography starting at age 45 years. (Strong Recommendation)

1a. Women aged 45-54 years should be screening annually. (Qualified Recommendation)

1b. Women 55 years and older should transition to biennial screening or have the opportunity to continue screening annually. (Qualified Recommendation)

1c. Women should have the opportunity to begin annual screening between the ages of 40 and 44 years. (Qualified Recommendation)

2. Women should continue screening mammography as long as their overall health is good and they have a life expectancy of 10 years or longer. (Qualified Recommendation)

3. The ACS does not recommend CBE for breast cancer screening among average-risk women at any age. (Qualified Recommendation)

These new guidelines bring the USPSTF and ACS recommendation closer to one another; they provide a clear step toward consensus. Both guidelines now agree that for average-risk women who are younger than 45 years, the harms of screening mammography likely outweigh the benefits. They are also consistent in their position that for women older than 55 years, biennial mammography is likely to provide the best balance of benefits to harms. Finally, they both recommend decisions to be individualized to reflect a woman’s preferences and her underlying risk of breast cancer.

Differences between the two guidelines originate from several methodological decisions made by the group responsible for the new ACS guidelines. In addition to randomized controlled trials and mathematic modeling, the group reviewed and utilized results from recent observational studies. The group also decided to analyze the benefits and harms of mammography using 5-year age groups, rather than the conventional 10 years. Also, it assessed annual vs. biennial screening, finding that the proportion of tumors that were stage IIB or higher and larger than 15 mm was greater for premenopausal women undergoing biennial screening but not for postmenopausal women.

Several messages are worth emphasizing as clinicians continue to review these new guidelines and decide whether or not to incorporate them into practice. First, thanks to breakthroughs in breast cancer treatment, the majority of women who are diagnosed with breast cancer will do well regardless of whether their cancer was found by mammography. Evidence from randomized trials of women in their 40s and 50s suggests that screening mammography only decreases breast cancer mortality by approximately 15%. Thus, about 85% of women in their 40s and 50s who die of breast cancer would have died regardless of mammography screening. Furthermore, because of the low risk of breast cancer for women in their 40s, this relative benefit of 15% translates to a small absolute benefit of around 5 of 10,000 women likely to have a breast cancer death prevented by mammography. Obviously the absolute benefit is higher for women with an increased risk of breast cancer, highlighting the importance of identifying higher-risk women. The lifetime risk of dying from breast cancer with no screening is 2.7%. Using the screening guidelines of the USPSTF that risk decreases to 2% with a total of 13 mammograms by 74 years of age. Using the new screening guidelines from the ACS, the calculated risk of dying from breast cancer is 1.8%-1.9% with 20 mammograms by 74 years of age. This is a significant departure from the 35 mammograms that were recommended by the older 2003 ACS guidelines.

Bottom line

The American Cancer Society has released a 2015 update to its breast cancer screening guidelines for women at average risk. The new guidelines recommend against clinical breast exams and in favor of annual mammograms between ages 45 and 54 years, followed by biennial mammograms starting at age 55 years and ending when life expectancy is less than 10 years. These guidelines also allow for patient preference or clinical judgment to opt in for annual mammography from 40 to 44 years of age and to continue with annual screening beyond age 55.

References

1. Keating NL, Pace LE. New guidelines for breast cancer screening in U.S. women. JAMA. 2015;314(15)1658.

2. Kerlikowske K. Progress toward consensus on breast cancer screening guidelines and reducing screening harms. JAMA Intern Med. 2015 Oct 20. doi:10.1001/jamainternmed.2015.6466.

3. Oeffinger KC, Fontham ETH, Etzioni R, et al. Breast cancer screening for women at average risk. JAMA. 2015;314(15):1599-614. doi:10/1001/jama.2015.12783.

Dr. Skolnik is associate director of the family medicine residency program at Abington (Pa.) Memorial Hospital. Dr. Lyons is a third-year resident in the program.

Breast cancer is the most common cancer in women and ranks second, after lung cancer, as a cause of cancer-related death in women.

In the United States alone, an estimated 231,840 women will be diagnosed with breast cancer in 2015. Largely as a result of screening mammography and early detection, associated mortality has been steadily declining since 1990. Still, the American Cancer Society has estimated that 40,290 U.S. women will die of breast cancer in 2015.

Specific recommendations for breast cancer screening vary significantly between two major guidelines: the U.S. Preventive Services Task Force (USPSTF) and the American Cancer Society (ACS). In 2003, the ACS recommended annual screening with mammography for women beginning at age 40, stopping only when a woman’s health would preclude her from cancer treatment. Furthermore, the ACS recommended a clinical breast examination (CBE) at least every 3 years for women in their 20s and 30s and then annually starting at age 40. Current USPSTF guidelines recommend mammograms biennially from age 50 to age 74, finding insufficient evidence to recommend CBE.

Gaps between these two organizations are shrinking, however, as the ACS released its new 2015 guidelines, updating the 2003 recommendations for breast cancer screening for women at average risk. The ACS defined average risk broadly: women without a personal history of breast cancer, a confirmed or suspected genetic mutation known to increase risk of breast cancer (e.g., BRCA), or a history of previous radiotherapy to the chest at a young age. These guidelines include the following recommendations:

1. Women with an average risk of breast cancer should undergo regular screening mammography starting at age 45 years. (Strong Recommendation)

1a. Women aged 45-54 years should be screening annually. (Qualified Recommendation)

1b. Women 55 years and older should transition to biennial screening or have the opportunity to continue screening annually. (Qualified Recommendation)

1c. Women should have the opportunity to begin annual screening between the ages of 40 and 44 years. (Qualified Recommendation)

2. Women should continue screening mammography as long as their overall health is good and they have a life expectancy of 10 years or longer. (Qualified Recommendation)

3. The ACS does not recommend CBE for breast cancer screening among average-risk women at any age. (Qualified Recommendation)

These new guidelines bring the USPSTF and ACS recommendation closer to one another; they provide a clear step toward consensus. Both guidelines now agree that for average-risk women who are younger than 45 years, the harms of screening mammography likely outweigh the benefits. They are also consistent in their position that for women older than 55 years, biennial mammography is likely to provide the best balance of benefits to harms. Finally, they both recommend decisions to be individualized to reflect a woman’s preferences and her underlying risk of breast cancer.

Differences between the two guidelines originate from several methodological decisions made by the group responsible for the new ACS guidelines. In addition to randomized controlled trials and mathematic modeling, the group reviewed and utilized results from recent observational studies. The group also decided to analyze the benefits and harms of mammography using 5-year age groups, rather than the conventional 10 years. Also, it assessed annual vs. biennial screening, finding that the proportion of tumors that were stage IIB or higher and larger than 15 mm was greater for premenopausal women undergoing biennial screening but not for postmenopausal women.

Several messages are worth emphasizing as clinicians continue to review these new guidelines and decide whether or not to incorporate them into practice. First, thanks to breakthroughs in breast cancer treatment, the majority of women who are diagnosed with breast cancer will do well regardless of whether their cancer was found by mammography. Evidence from randomized trials of women in their 40s and 50s suggests that screening mammography only decreases breast cancer mortality by approximately 15%. Thus, about 85% of women in their 40s and 50s who die of breast cancer would have died regardless of mammography screening. Furthermore, because of the low risk of breast cancer for women in their 40s, this relative benefit of 15% translates to a small absolute benefit of around 5 of 10,000 women likely to have a breast cancer death prevented by mammography. Obviously the absolute benefit is higher for women with an increased risk of breast cancer, highlighting the importance of identifying higher-risk women. The lifetime risk of dying from breast cancer with no screening is 2.7%. Using the screening guidelines of the USPSTF that risk decreases to 2% with a total of 13 mammograms by 74 years of age. Using the new screening guidelines from the ACS, the calculated risk of dying from breast cancer is 1.8%-1.9% with 20 mammograms by 74 years of age. This is a significant departure from the 35 mammograms that were recommended by the older 2003 ACS guidelines.

Bottom line

The American Cancer Society has released a 2015 update to its breast cancer screening guidelines for women at average risk. The new guidelines recommend against clinical breast exams and in favor of annual mammograms between ages 45 and 54 years, followed by biennial mammograms starting at age 55 years and ending when life expectancy is less than 10 years. These guidelines also allow for patient preference or clinical judgment to opt in for annual mammography from 40 to 44 years of age and to continue with annual screening beyond age 55.

References

1. Keating NL, Pace LE. New guidelines for breast cancer screening in U.S. women. JAMA. 2015;314(15)1658.

2. Kerlikowske K. Progress toward consensus on breast cancer screening guidelines and reducing screening harms. JAMA Intern Med. 2015 Oct 20. doi:10.1001/jamainternmed.2015.6466.

3. Oeffinger KC, Fontham ETH, Etzioni R, et al. Breast cancer screening for women at average risk. JAMA. 2015;314(15):1599-614. doi:10/1001/jama.2015.12783.

Dr. Skolnik is associate director of the family medicine residency program at Abington (Pa.) Memorial Hospital. Dr. Lyons is a third-year resident in the program.

Breast cancer is the most common cancer in women and ranks second, after lung cancer, as a cause of cancer-related death in women.

In the United States alone, an estimated 231,840 women will be diagnosed with breast cancer in 2015. Largely as a result of screening mammography and early detection, associated mortality has been steadily declining since 1990. Still, the American Cancer Society has estimated that 40,290 U.S. women will die of breast cancer in 2015.

Specific recommendations for breast cancer screening vary significantly between two major guidelines: the U.S. Preventive Services Task Force (USPSTF) and the American Cancer Society (ACS). In 2003, the ACS recommended annual screening with mammography for women beginning at age 40, stopping only when a woman’s health would preclude her from cancer treatment. Furthermore, the ACS recommended a clinical breast examination (CBE) at least every 3 years for women in their 20s and 30s and then annually starting at age 40. Current USPSTF guidelines recommend mammograms biennially from age 50 to age 74, finding insufficient evidence to recommend CBE.

Gaps between these two organizations are shrinking, however, as the ACS released its new 2015 guidelines, updating the 2003 recommendations for breast cancer screening for women at average risk. The ACS defined average risk broadly: women without a personal history of breast cancer, a confirmed or suspected genetic mutation known to increase risk of breast cancer (e.g., BRCA), or a history of previous radiotherapy to the chest at a young age. These guidelines include the following recommendations:

1. Women with an average risk of breast cancer should undergo regular screening mammography starting at age 45 years. (Strong Recommendation)

1a. Women aged 45-54 years should be screening annually. (Qualified Recommendation)

1b. Women 55 years and older should transition to biennial screening or have the opportunity to continue screening annually. (Qualified Recommendation)

1c. Women should have the opportunity to begin annual screening between the ages of 40 and 44 years. (Qualified Recommendation)

2. Women should continue screening mammography as long as their overall health is good and they have a life expectancy of 10 years or longer. (Qualified Recommendation)

3. The ACS does not recommend CBE for breast cancer screening among average-risk women at any age. (Qualified Recommendation)

These new guidelines bring the USPSTF and ACS recommendation closer to one another; they provide a clear step toward consensus. Both guidelines now agree that for average-risk women who are younger than 45 years, the harms of screening mammography likely outweigh the benefits. They are also consistent in their position that for women older than 55 years, biennial mammography is likely to provide the best balance of benefits to harms. Finally, they both recommend decisions to be individualized to reflect a woman’s preferences and her underlying risk of breast cancer.

Differences between the two guidelines originate from several methodological decisions made by the group responsible for the new ACS guidelines. In addition to randomized controlled trials and mathematic modeling, the group reviewed and utilized results from recent observational studies. The group also decided to analyze the benefits and harms of mammography using 5-year age groups, rather than the conventional 10 years. Also, it assessed annual vs. biennial screening, finding that the proportion of tumors that were stage IIB or higher and larger than 15 mm was greater for premenopausal women undergoing biennial screening but not for postmenopausal women.

Several messages are worth emphasizing as clinicians continue to review these new guidelines and decide whether or not to incorporate them into practice. First, thanks to breakthroughs in breast cancer treatment, the majority of women who are diagnosed with breast cancer will do well regardless of whether their cancer was found by mammography. Evidence from randomized trials of women in their 40s and 50s suggests that screening mammography only decreases breast cancer mortality by approximately 15%. Thus, about 85% of women in their 40s and 50s who die of breast cancer would have died regardless of mammography screening. Furthermore, because of the low risk of breast cancer for women in their 40s, this relative benefit of 15% translates to a small absolute benefit of around 5 of 10,000 women likely to have a breast cancer death prevented by mammography. Obviously the absolute benefit is higher for women with an increased risk of breast cancer, highlighting the importance of identifying higher-risk women. The lifetime risk of dying from breast cancer with no screening is 2.7%. Using the screening guidelines of the USPSTF that risk decreases to 2% with a total of 13 mammograms by 74 years of age. Using the new screening guidelines from the ACS, the calculated risk of dying from breast cancer is 1.8%-1.9% with 20 mammograms by 74 years of age. This is a significant departure from the 35 mammograms that were recommended by the older 2003 ACS guidelines.

Bottom line

The American Cancer Society has released a 2015 update to its breast cancer screening guidelines for women at average risk. The new guidelines recommend against clinical breast exams and in favor of annual mammograms between ages 45 and 54 years, followed by biennial mammograms starting at age 55 years and ending when life expectancy is less than 10 years. These guidelines also allow for patient preference or clinical judgment to opt in for annual mammography from 40 to 44 years of age and to continue with annual screening beyond age 55.

References

1. Keating NL, Pace LE. New guidelines for breast cancer screening in U.S. women. JAMA. 2015;314(15)1658.

2. Kerlikowske K. Progress toward consensus on breast cancer screening guidelines and reducing screening harms. JAMA Intern Med. 2015 Oct 20. doi:10.1001/jamainternmed.2015.6466.

3. Oeffinger KC, Fontham ETH, Etzioni R, et al. Breast cancer screening for women at average risk. JAMA. 2015;314(15):1599-614. doi:10/1001/jama.2015.12783.

Dr. Skolnik is associate director of the family medicine residency program at Abington (Pa.) Memorial Hospital. Dr. Lyons is a third-year resident in the program.