On April 8, 2019, the American College of Physicians (“ACP”) released the clinical guideline, “Screening for Breast Cancer in Average-Risk Women: A Guidance Statement from the American College of Physicians” (the “Guideline”). The Guideline divides women into three categories based on age and offers breast cancer screening methodology guidance for each category. The Guideline offers the following guidance for women of average-risk:
- Women aged 40-49: clinicians should discuss whether to screen for breast cancer with mammography, including a discussion on the benefits and harms of screening as well as the woman’s preference. The ACP notes that potential harms generally outweigh the benefits for most women in this category;
- Women aged 50-74: clinicians should offer biennial screening for breast cancer with mammography;
- Women aged 75 years or older: clinicians should discontinue breast cancer screening with mammography for women of this age and for women with a life expectancy of 10 years or less.
- All ages: clinicians should not use clinical breast examination to screen for breast cancer.
Note that women of average risk are defined as “those who do not have a personal history of breast cancer or a previous diagnosis of a high-risk breast lesion, are not a high risk for breast cancer due to genetic mutations known to increase that risk (such as BRCA1/2 gene mutation or another familial breast cancer syndrome), and were not exposed to radiation therapy to the chest in childhood.”
The ACP developed the Guideline to provide clinicians with a rigorous review of available guidelines and to develop its own guidance for clinicians based on an assessment of those guidelines. Utilizing the Appraisal of Guidelines for Research and Evaluation II (AGREE II) instrument, the Guideline assesses breast cancer screening guidelines from the following:
- American College of Obstetricians and Gynecologists (ACOG)
- American College of Radiology (ACR)
- American Cancer Society (ACS)
- Canadian Task Force on Preventive Health Care (CTFPHC)
- National Comprehensive Cancer Network (NCCN)
- S. Preventive Services Task Force (USPSTF)
- World Health Organization (WHO)
The ACP found the guidelines from the ACS, CTFPHC, USPSTF, and WHO scored highest on the AGREE II instrument, while guidelines from the ACR, ACOG, and NCCN scored lowest. The ACP found that the lower scoring guidelines often inadequately described how they considered applicable factors (e.g., variance in studies reported, weighting of observational/modeling studies, etc.) in establishing guidelines, or they relied on lower-quality evidence. Further, the ACP asserted that the lower scoring guidelines rarely addressed the small absolute effect screening has on breast cancer mortality.
The Guideline discusses benefits and harms arising from mammography and clinical breast examinations (CBEs), as well as shortfalls of the assessed guidelines. There are also short summaries of each assessed guideline and its recommendations. Further, the Guideline breaks down each assessed guideline in a table, detailing its recommendations regarding: (1) a clinical breast examination (CBE); (2) age to begin mammography screening and/or initiate discussions about screening; (3) age to stop mammography screening; and (4) screening intervals. This should be quite useful to a radiation provider or supplier considering which screening standard to implement.
After reviewing the Guideline, it appears to be an amalgamation of the assessed guidelines. For instance, the ACOG and USPSTF guidelines recommend beginning discussions regarding screening at age 40; the ACOG, CTFPHC, USPSTF, and WHO guidelines each recommend screening to begin at age 50; the ACOG, USPSTF, and WHO guidelines recommend ending screening at age 75; and the ACS recommends ceasing screening if life expectancy is less than 10 years. The Guideline incorporated each of these recommendations into its own guidance.
It is important to note that the ACR has cautioned providers from relying on the Guideline. According to the ACR, biennial screenings of only women ages 50-74 may result in a higher mortality rate due to preventable breast cancer deaths. The ACR projects as many as 10,000 additional deaths per year due to such screening practices. The ACR believes the ACP fails to consider relevant trials indicating annual screening reduces mortality rates. Further, the ACR believes the ACP Guidelines fail to appropriately consider racial disparities, as non-white women have a higher rate of being diagnosed with breast cancer before age 50 and a higher mortality rate. Overall, the ACR believes the ACP Guideline greatly underestimates mammography benefits while overestimating potential harm. By contrast, the ACR recommends scheduling a risk assessment by the age of 30 to determine if earlier breast cancer screening is necessary, annual screening to begin at the age of 40, and continued screenings for as long as the woman is healthy.