Comparative effectiveness of strategies to prevent weight gain among women with and at risk for breast cancer: a systematic review

BACKGROUND Obesity affects cancer risk and treatment outcomes. Preventing weight gain may prevent some cancers, improve cancer outcomes, reduce cancer recurrence and increase cancer-related survival. We performed a systematic review to identify strategies to prevent weight gain in individuals with or at risk for breast cancer. FINDINGS We included 2 studies from 27,879 citations. In premenopausal women at risk for breast cancer, a low fat diet prevented weight gain at 12 months. Among women with breast cancer, effective strategies to prevent weight gain included low-fat dietary counseling with self-management techniques. One trial reported on cancer outcomes, mortality and adverse events. Low-fat dietary counseling wilth self-management techniques lowers the risk breast cancer relapse by 24% compared with less intensive counseling with maintenance of nutritional status goal. There was no difference in overall mortality and no adverse events were observed. CONCLUSION Limited evidence suggests that women with or at risk for breast cancer may successfully employ dietary and exercise strategies to prevent weight gain for at least one year. Low fat dietary counseling may improve cancer outcomes in women with breast cancer. Future studies should confirm these findings and evaluate the impact of weight gain prevention on cancer incidence, recurrence and survival.