Racial differences in physical activity among breast cancer survivors: implications for breast cancer care.

BACKGROUND: Physical activity after breast cancer diagnosis is associated with improved survival. The current study examined levels of and changes in physical activity after breast cancer diagnosis, overall and by race.
METHODS: Phase 3 of the Carolina Breast Cancer Study assessed both pre- and postdiagnosis physical activity levels in a cohort of 1735 women aged 20 years to 74 years who were diagnosed with invasive breast cancer between 2008 and 2011 in 44 counties of North Carolina. Logistic regression and analysis of variance were used to examine whether demographic, behavioral, and clinical characteristics were associated with activity levels.
RESULTS: Only 35% of study participants met current physical activity guidelines after diagnosis with breast cancer. A decrease in activity after diagnosis was reported by 59% of patients, with the average study participant reducing their activity by 15 metabolic equivalent task (MET) hours (95% confidence interval [95% CI], 12 MET hours-19 MET hours). After adjustment for potential confounders, when compared with white women, African American women were less likely to meet national physical activity guidelines after diagnosis (odds ratio, 1.38; 95% CI, 1.01-1.88) and reported less weekly postdiagnosis physical activity (12 MET hours vs 14 MET hours; P = .13). In adjusted stratified analyses, receipt of treatment was found to be significantly associated with postdiagnosis activity in African American women (P < 0.01).
CONCLUSIONS: Despite compelling evidence demonstrating the benefits of physical activity after a diagnosis of breast cancer, it is clear that more work needs to be done to promote physical activity in patients with breast cancer, especially among African American women.