The excellent article by Welch and Frankel1 helps put the benefits of mammography into perspective. I agree with their conclusion that the likelihood that a woman with a screen-detected breast cancer has had her life saved by that screening is small. The authors' methods, however, were indirect. They used Surveillance Epidemiology and End Results (SEER) data regarding breast cancer incidence and mortality and then made a number of assumptions regarding the proportion of breast cancers detected by screening, the benefit that has already been achieved from screening, and the time course during which the mortality reduction from mammography should be seen. I would like to point out that this question can also be addressed directly by analyzing data from the randomized mammography trials.