Screening Mammography for Women 40 to 49 Years of Age: A Clinical Practice Guideline from the American College of Physicians

Breast cancer is one of the most common causes of death for women in their 40s in the United States. Individualized risk assessment plays an important role when making decisions about screening mammography, especially for women 49 years of age or younger. The purpose of this guideline is to present the available evidence for screening mammography in women 40 to 49 years of age and to increase clinicians' understanding of the benefits and risks of screening mammography.

Summary

Screening mammography probably reduces breast cancer mortality in women 40 to 49 years of age modestly. However, the reduction in this age group is smaller than that in women 50 years of age or older, is subject to greater uncertainty about the exact reduction in risk, and comes with the risk for potential harms (such as false-positive and false-negative results, exposure to radiation, discomfort, and anxiety).

Because of the variation in benefits and harms associated with screening mammography, we recommend tailoring the decision to screen women on the basis of women's concerns about mammography and breast cancer, as well as their risk for breast cancer. Assessment of an individual woman's risk for breast cancer is important because the balance of harms and benefits will shift to net benefit as a woman's baseline risk for breast cancer increases, all other factors being equal. For many women, the potential reduction in risk for death due to breast cancer associated with screening mammography will outweigh other considerations.