Changes in breast self-examination behavior in a cohort of 8214 women in the Canadian national breast screening study

A study cohort of 8214 women was formed from all participants in the Canadian National Breast Screening Study who attended their first three screens after the introduction of a structured evaluation protocol involving eight criteria for breast self-examination (BSE). Self-reported BSE frequency was collected by questionnaire at all three screens. Breast self-examination instruction preceded breast exam at each screen but BSE evaluation occurred only at the second and third screen. Reported monthly BSE frequency increased from 18% to 51% to 55% on first, second, and third screens, respectively. The proportion claiming to do no BSE fell correspondingly: 52%, 16%, and 11%. Compliance with each of the seven other BSE criteria was significantly greater at the third screen than at the second. The mean number of these criteria performed at screen 3 was 5.1 compared with 4.4 at screen 2; older women performed as well as younger. The mean number of criteria performed was associated with BSE frequency at screen 3. The authors conclude that women's BSE behavior can be altered, and that integration of BSE evaluation and instruction into routine medical exams seems feasible and potentially useful.