Overdiagnosis can result in overtreatment, physical harm, and emotional distress. Using SEER-Medicare data, researchers examined breast cancer overdiagnosis by comparing cancer incidence among women who discontinued mammography screening after age 70 compared to women who continued to receive screening mammograms. Findings suggest that breast cancer may be potentially overdiagnosed among 31% of women aged 70 to 74 years, 47% of women aged 75 to 84 years, and 54% of women aged 85 and older who continue to receive screening mammograms.