Exercise and quality of life during and after treatment for breast cancer: results of two randomized controlled trials.

OBJECTIVE: To determine the effect of exercise on quality of life in (a) a randomized controlled trial of exercise among recently diagnosed breast cancer survivors undergoing adjuvant therapy and (b) a similar trial among post-treatment survivors. METHODS: Fifty newly diagnosed breast cancer survivors were recruited through a hospital-based tumor registry and randomized to a 6-month, home-based exercise program (n=25) or a usual care group (n=25). In a separate trial, 75 post-treatment survivors were randomized to a 6-month, supervised exercise intervention (n=37) or to usual care (n=38). Participants in both studies completed measures of happiness, depressive symptoms, anxiety, stress, self-esteem, and quality of life at baseline and 6 months. RESULTS: Forty-five participants completed the trial for newly diagnosed survivors and 67 completed the trial for post-treatment survivors. Good adherence was observed in both studies. Baseline quality of life was similar for both studies on most measures. Exercise was not associated with quality of life benefits in the full sample of either study; however exercise was associated with improved social functioning among post-treatment survivors who reported low social functioning at baseline (p<0.05). CONCLUSIONS: Exercise did not affect quality of life in either recently diagnosed or post-treatment breast cancer survivors; however this may be due in part to relatively high baseline functioning among participants in both studies. Strategies for future research include limiting enrollment to survivors who report reduced quality of life on screening questionnaires and targeting survivor subgroups known to be at particular risk for quality of life impairment.

Physical activity, diet, adiposity and female breast cancer prognosis: a review of the epidemiologic literature.

Given the increasing numbers of long-term survivors of breast cancer, research specific to prevention of recurrence, new breast cancer events, and mortality is of considerable public health importance. The objective of this report is to present a review of the published epidemiologic research on lifestyle and breast cancer outcomes among women with a history of breast cancer. This review focused on physical activity, diet, and adiposity; and the primary outcomes were additional breast cancer events and mortality. The most consistent finding from observational studies was that adiposity was associated with a 30% increased risk of mortality. Although the observational data were not as consistent (or abundant), physical activity appeared to be associated with a 30% decreased risk of mortality. These data do not indicate that alcoholic drinks are a risk factor. Based only on the observational studies, total dietary fat appeared to be a risk factor, fiber was protective, and information on micronutrients and specific foods was sparse. However, the null results of 2 dietary intervention trials in survivors suggests that lowering fat intake or increasing consumption of fruits, vegetables, and fiber will not lead to improved prognosis in breast cancer survivors. Given that a high proportion of breast cancer patients appear to be both sedentary and obese/overweight, clinical trials are needed to investigate whether the combination of increased physical activity and reduced adiposity can improve breast cancer prognosis.