A longitudinal study of physical activity and breast cancer prediction

Physical activity was analyzed as a predictor of breast cancer in the Aerobic Center Longitudinal Study. The study sample included 4,520 healthy women, with 150 incident cases of breast cancer. The study sample was limited to women who did not have a diagnosis of breast cancer at initial entry to the Aerobic Center Longitudinal Study. Women in the study were predominantly from an upper-middle class, college-educated, Caucasian American group being evaluated at a world-famous fitness center. Women with and without breast cancer had similar reports for diet history, alcohol and tobacco use, body composition, and breast health history. Women with breast cancer were older and had an earlier menarche and later menopause. Logistic regression analysis of physical activity for women with and without breast cancer was performed controlling for age. Intensity and duration of physical activity were not predictors of breast cancer. Less frequency of jogging was a significant predictor of breast cancer among women in the sample, O.R.=1.14, P =.04. Women who reported jogging as a type of activity were less likely to develop breast cancer than those who did not report jogging, O.R.=2.32, P=0.05.