Maintenance of physical activity and body weight in relation to subsequent quality of life in postmenopausal breast cancer patients.

BACKGROUND We prospectively examined the association between physical activity, body weight and quality of life in Dutch postmenopausal early breast cancer patients treated with adjuvant endocrine therapy. PATIENTS AND METHODS In this side study of a large clinical trial, lifestyle and quality-of-life questionnaires were filled out 1 and 2 years after the start of endocrine therapy (T1 and T2, respectively) and included a pre-diagnosis lifestyle assessment (T0). A total of 435 breast cancer patients returned both questionnaires. RESULTS Individuals with a physical activity level above the median who maintained this level from T0 to T1 reported the best global quality of life and physical functioning and the least fatigue at T2, as compared with individuals with low levels of physical activity which further decreased after diagnosis (difference of +16, +14, and -22 points on a 0-100 quality-of-life scale, respectively; P < 0.01). Overweight or obese women who gained body weight after diagnosis reported worst quality of life and most fatigue as compared with women who maintained a stable body weight (difference of -8, -10 and +2 points, respectively; P < 0.01). CONCLUSION Maintaining high pre-diagnosis physical activity levels and a healthy body weight is associated with better quality of life after breast cancer.