Abstract B45: Physical activity and breast cancer among Latina women

Physical activity has been linked to reduced breast cancer risk. Latina women, especially those residing on the Texas-Mexico border, have fairly low rates of leisure-time physical activity. We used data from a case-control study of breast cancer among Hispanic women aged 30 to 79 conducted between 2003 and 2008 to investigate whether physical activity was associated with reduced risk of breast cancer. In-person interviews were completed with 192 incident breast cancer cases ascertained through surgeons and oncologists, and 467 controls who had two consecutive negative screening mammograms (with respective response rates of 97% and 74%). Fewer than 40% of breast cancer cases and just over half of control women (52.7%) reported they had engaged in leisure-time physical activity in the past three years. After adjustment for age, menopausal status, body mass index, and hormone replacement therapy there was a reduction in breast cancer risk associated with any physical activity (odds ratio [OR] 0.58, 95% confidence interval [CI] 0.40–0.82). When we divided the group of women who had engaged in physical activity into tertiles the reduced risk remained (highest tertile relative to no physical activity OR 0.56, 95% CI 0.33–0.95); however, there was no trend of decreasing risk with increasing physical activity (p=0.22). Our findings indicate that although Latina women report engaging in very little leisure-time physical activity, its' effect on breast cancer risk is comparable to other racial and ethnic groups. Latina women should be encouraged to combine their work-related and housework-related physical activity with leisure-time physical activity to reduce their risk of breast cancer and other chronic diseases.