Estimated effect of breast self-examination and routine physician examinations on breast-cancer mortality.

We examined the effects of breast self-examination and breast examination by physicians on the stage of breast cancer at diagnosis. Clinical and pathological-staging information was compared to interview data on method of initial detection of 293 women. Tumors were detected in clinical Stage I 53.8% of the time when the detection method was routine physician examination, 37.7% when it was self-examination and only 27.0% when detection was accidental. Sixty-nine per cent of women practicing self-examination at the time of diagnosis discovered their tumor by this method. Differences were less apparent when pathological stage was considered. Tumors found during routine examination of the breast averaged 6.1 mm smaller in diameter than those discovered accidentally. We estimate that breast-cancer mortality might be reduced by 18.8% to 24.4% through self-examination or routine physician examination, respectively.