Physical activity and the risk of breast cancer recurrence: a literature review.

PURPOSE/OBJECTIVES To examine the association between physical activity and breast cancer mortality and recurrence, and to provide an overview of factors related to physical activity behavior in women with breast cancer. DATA SOURCES An extensive review of the epidemiologic literature on the effect of physical activity on breast cancer recurrence and mortality was conducted using PubMed up to December 2010, involving the following key words: physical activity, exercise, breast cancer, breast cancer recurrence, and breast cancer mortality. DATA SYNTHESIS For breast cancer recurrence and breast cancer-related mortality, studies were included if physical activity served as the independent variable and a measure of association was reported. To examine determinants of physical activity, studies were included if a hypothesized factor served as the independent variable and a measure of association was reported. CONCLUSIONS Of the six studies that examined the influence of physical activity on breast cancer mortality, four (67%) reported a protective effect (i.e., inverse association), two examined the influence of physical activity on breast cancer recurrence and reported a nonsignificant risk reduction. Few studies have examined factors that influence physical activity behavior in women with breast cancer, and findings suggest that psychosocial factors play an important role in influencing the activity patterns of breast cancer survivors. Future longitudinal studies are needed to confirm those findings. IMPLICATIONS FOR NURSING To prevent breast cancer recurrence and breast cancer-related mortality, nurses should encourage breast cancer survivors to engage in regular exercise.