To the Editor.— Breast self-examination, physical examination, and mammography lack the accuracy necessary to be considered diagnostic tools for breast cancer. They are, however, screening tools that, when aggressively used, will discover many highly curable, small cancers (in situ lobular, in situ ductal, and intraductal cancer with less than 10% microinvasion, 5-mm invasive cancer, or tubular cancer), which we estimate to have a 20-year relative survival rate of 90%. As the article by Lesnick (237:967, 1977) has so eloquently shown, these modalities, as currently practiced in the nonscreen setting, are of very little value in detecting these small cancers in younger women. Contrariwise, our experience at the Breast Cancer Demonstration Project in Cincinnati indicates that of 17 cancers found in self-selected volunteers aged 35 to 44 years, 12 (71%) were minimal. Ten of 17 (58%) were found by mammography alone, and eight of ten found by mammography alone were minimal.