Screening Women in Their 40S

Conflicting breast cancer screening guidelines for women in their 40s are based on different interpretations of research and considerations of benefits and harms. Breast cancer mortality was not reduced in eight randomized controlled screening trials of women in their 40s, but was reduced by 26% to 44% in two observational studies. Incidence of advanced breast cancer and all-cause mortality were also not reduced in the screening trials. False-positive mammography rates were higher for women in their 40s and those with risk factors for breast cancer. Rates of false-negative results and recommendations for biopsy did not differ by age. Additional harms of screening include overdiagnosis and overtreatment; radiation exposure; and anxiety, distress, and pain during procedures, however, their impact on individual women is unclear. Due to the uncertainty of the benefits and harms of mammography screening for women in their 40s, shared decision-making has become an important part of the screening process.