Relationship between breast self-examination and death from breast cancer by age groups.

To quantitate the relationship between breast self-examination and survival from breast cancer, we have studied 1,003 newly diagnosed patients with invasive breast cancer in Vermont general hospitals since July 1, 1975. Death certificates, autopsy reports, and hospital records were reviewed to determine the cause of death. Examination of product limit survival curves by three age groups demonstrated that death due to breast cancer was less likely in breast cancer patients who had performed breast self-examination than in nonperformers in each of the three age groups. The associated lead-time would have to exceed 36 months to negate the apparent beneficial effects of breast self-examination in decreasing the likelihood of death from breast cancer. We conclude that in this population of breast cancer patients, breast self-examination probably contributed to earlier detection and thereby improved survival.