ACOG recommends annual mammograms for women starting at age 40

New breast cancer screening guidelines from the American College of Obstetricians and Gynecologists (ACOG) recommend offering annual screening mammography to women beginning at 40 years of age. Previous recommendations called for mammograms every 1 or 2 years starting at age 40 and annual mammograms starting at age 50.

The new guidelines are based on the incidence of breast cancer, the sojourn time (that is, the time between detection and when the cancer grows large enough to cause symptoms), and the potential to reduce the number of deaths from the cancer. Women between 40 and 49 years of age have the shortest average sojourn time (2 to 2.4 years); women 70 to 74 years of age have the longest average sojourn time (4 to 4.1 years).

ACOG notes that no consensus exists on the upper age limit for mammograms; the benefits decrease with advancing age relative to the harms of overtreatment. Women 75 years of age and older should discuss with their doctor whether to continue mammograms.

Organizations including the American College of Radiology, the Society of Breast Imaging, and Susan G. Komen for the Cure have endorsed the new guidelines. The American Cancer Society and the National Comprehensive Cancer network also recommend starting mammography at age 40. The United States Preventive Services Task Force, however, recommends that mammography before 50 years of age should be an individual decision and should be done every other year after 50. The Task Force cites the small benefit of earlier mammography in relation to the risks.

ACOG Practice Bulletin #122, “Breast Cancer Screening,” was published in Obstetrics & Gynecology (2011;118[2 Part 1]:372-382).