Continued breast cancer screening among women aged 70 and older is associated with an increased incidence of breast cancer, indicating overdiagnosis, according to a study published in the Annals of Internal Medicine. Ilana B. Richman, MD, and colleagues estimated overdiagnosis in a retrospective cohort study comparing the cumulative incidence of breast cancer among women aged 70 and older who had recently been screened and who continued or did not continue screening in the next interval. Data were included for 54,635 women who were followed for breast cancer diagnoses and breast cancer death for up to 15 years. The adjusted cumulative incidence of breast cancer was 6.1 versus 4.2 cases per 100 screened and unscreened women aged 70-74. Among screened women, an estimated 31% of breast cancers were potentially over diagnosed. The cumulative incidence was 4.9 versus 2.6 per 100 screened and unscreened women among those aged 75-84, with potential overdiagnosis for 47% of cases. The cumulative incidence was 2.8 and 1.3 per 100 screened and unscreened women, respectively, aged 85 and older, with over-diagnosis of up to 54%.
