Variation of Benefits and Harms of Breast Cancer Screening With Age

The critical issue in deciding whether to recommend breast cancer screening for women in their forties is to determine whether potential benefits are substantially greater than potential harms. Recent evidence from randomized clinical trials makes it likely that, after 10-12 years of follow-up, there is a real benefit from screening women ages 40-49, on the order of a 15-20% reduction in the relative risk of breast cancer death. This relative...