Impact of exercise on chemotherapy completion rate: A systematic review of the evidence and recommendations for future exercise oncology research

Receipt of full chemotherapy dose is associated with improved treatment efficacy and survival following a diagnosis of cancer. Exercise has emerged as a supportive care intervention that may improve chemotherapy completion rate by managing dose-limiting toxicities. We conducted a systematic review to evaluate the impact of exercise interventions on outcomes of chemotherapy completion rate in adult cancer patients. Relevant literature was retrieved from CINAHL, Medline (Ovid) and EMBASE based on subject headings and keywords pertaining to cancer, exercise and antineoplastic agents. Eligible articles were randomized control trials (RCTs) that prescribed aerobic or resistance exercise and included end-points relating to chemotherapy completion rate. Overall, eight RCTs were included in the final analysis. Only two RCTs (25%) that enrolled women with early-stage breast cancer reported a significant beneficial effect of exercise on chemotherapy completion rate, including higher mean relative dose intensity and fewer chemotherapy dose adjustments, relative to usual care. The remaining six studies reported no difference with exercise. Altogether, despite the growing number of exercise oncology trials to-date, information pertaining to the effect of exercise on chemotherapy completion rate is limited. Current data suggest exercise does not worsen chemotherapy tolerability. However, full interpretation of these findings is limited by the small number of trials. Future research involving rigorous study design is needed to confirm whether exercise can influence chemotherapy treatments.