Practice Bulletin Number 179: Breast Cancer Risk Assessment and Screening in Average-Risk Women

Breast cancer is the most commonly diagnosed cancer in women in the United States and the second leading cause of cancer death in American women (1). Regular screening mammography starting at age 40 years reduces breast cancer mortality in average-risk women (2). Screening, however, also exposes women to harm through false-positive test results and overdiagnosis of biologically indolent lesions. Differences in balancing benefits and harms have led to differences among major guidelines about what age to start, what age to stop, and how frequently to recommend mammography screening in average-risk women (2-4).Breast cancer risk assessment is very important for identifying women who may benefit from more intensive breast cancer surveillance; however, there is no standardized approach to office-based breast cancer risk assessment in the United States. This can lead to missed opportunities to identify women at high risk of breast cancer and may result in applying average-risk screening recommendations to high-risk women. Risk assessment and identification of women at high risk allow for referral to health care providers with expertise in cancer genetics counseling and testing for breast cancer-related germline mutations (eg, BRCA), patient counseling about risk-reduction options, and cascade testing to identify family members who also may be at increased risk.The purpose of this Practice Bulletin is to discuss breast cancer risk assessment, review breast cancer screening guidelines in average-risk women, and outline some of the controversies surrounding breast cancer screening. It will present recommendations for using a framework of shared decision making to assist women in balancing their personal values regarding benefits and harms of screening at various ages and intervals to make personal screening choices from within a range of reasonable options. Recommendations for women at elevated risk and discussion of new technologies, such as tomosynthesis, are beyond the scope of this document and are addressed in other publications of the American College of Obstetricians and Gynecologists (ACOG) (5-7).