Benefit/risk analysis of aggressive mammographic screening.

Based on the results of aggressive screening of 20,000 women and an annual average midbreast absorbed dose of 1 rad per year, the authors describe a model for estimating the benefit/risk ratio for mammography in screening populations of asymptomatic, randomly selected women. Benefits in terms of breast-cancer deaths averted over not screening are estimated. The "worst-case" estimate of the benefit/risk ratio for five annual mammographic examinations on randomly selected asymptomatic women age 35-49 at the start of screening is 3.4 +/- 1.1 to 1. The corresponding "most probable" estimate is 8.0 +/- 3.1 to 1.