Effects of exercise on breast cancer patients and survivors: a systematic review and meta-analysis Margaret L. McNeely, Kristin L. Campbell, Brian H. Rowe, Terry P. Klassen, John R. Mackey and Kerry S. Courneya
From the Department of Behavioural Medicine, Faculty of Physical Education, University of Alberta (McNeely, Campbell, Courneya), the Department of Emergency Medicine, University of Alberta and Capital Health (Rowe), the Department of Paediatrics, Stollery Children's Hospital and University of Alberta (Klassen) and the Department of Medical Oncology, Cross Cancer Institute and University of Alberta (Mackey), Edmonton, Alta.
Background: Physical exercise has been identified as a potentialintervention to improve quality of life in women with breastcancer. We sought to summarize the available evidence concerningthe effects of exercise on breast cancer patients and survivors.
Methods: We searched the Cochrane Central Register of ControlledTrials, MEDLINE, EMBASE, CINAHL, PsychINFO, CancerLit, PEDroand SportDiscus as well as conference proceedings, clinical practice guidelines and other unpublished literature resources.We included only randomized controlled trials that examined exercise interventions for breast cancer patients or survivors with quality of life, cardiorespiratory fitness or physica lfunctioning as primary outcomes. We also extracted data on symptoms of fatigue, body composition and adverse effects.
Results: Of 136 studies identified, 14 met all the inclusioncriteria. Despite significant heterogeneity and relatively smallsamples, the point estimates in terms of the benefits of exercisefor all outcomes were positive even when statistical significancewas not achieved. Exercise led to statistically significan timprovements in quality of life as assessed by the Functional Assessment of Cancer Therapy–General (weighted mean difference[WMD] 4.58, 95% confidence interval [CI] 0.35 to 8.80) and Functional Assessment of Cancer Therapy–Breast (WMD 6.62, 95% CI1.21 to 12.03). Exercise also led to significant improvements in physical functioning and peak oxygen consumption and in reducing symptoms of fatigue.