Breast cancer among former college athletes compared to non-athletes: a 15-year follow-up.
A growing body of evidence indicates that physical activity is protective against breast cancer. In 1996-97, we conducted a 15-year follow-up of 5398 college alumnae comprised of former college athletes with their non-athletic classmates. Participants completed a detailed mailed questionnaire on their health history from 1981-82 to the present. Excluding women who had died and non-deliverable questionnaires, 84.7% (n = 3940) of the participants in our earlier study responded to the questionnaire; the response rate for former athletes was 86.6% (n = 1945), for non-athletes, 83.0% (n = 1995). Results confirmed our earlier findings. Based on self-reports, former college athletes had a significantly lower risk of breast cancer than the non-athletes. The OR for the 15-year incidence of breast cancer is 0.605 with 95% confidence interval (CI) (0.438-0.835); the 15-year incident breast cancers were 64 among the athletes and 111 among the non-athletes. Among women under 45 the protective effect of physical activity on the risk of breast cancer is considerably greater; odds ratio (OR) = 0.164, 95% CI (0.042-0.636). Athletic activity during the college and pre-college years is protective against breast cancer throughout the life span, and more markedly among women under 45. These results confirm our earlier findings and the findings of other investigators.
Wyshak
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Department of Population and International Health, Harvard School of Public Health, Boston, MA 02115, USA.
Frisch
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D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D013177:Sports