Physical Activity and Survival After Breast Cancer Diagnosis

CONTEXT Physical activity has been shown to decrease the incidence of breast cancer, but the effect on recurrence or survival after a breast cancer diagnosis is not known. OBJECTIVE To determine whether physical activity among women with breast cancer decreases their risk of death from breast cancer compared with more sedentary women. DESIGN, SETTING, AND PARTICIPANTS Prospective observational study based on responses from 2987 female registered nurses in the Nurses’ Health Study who were diagnosed with stage I, II, or III breast cancer between 1984 and 1998 and who were followed up until death or June 2002, whichever came first. MAIN OUTCOME MEASURE Breast cancer mortality risk according to physical activity category (