Exercise and colorectal cancer: a systematic review and meta-analysis of exercise safety, feasibility and effectiveness

Background This meta-analysis evaluated the safety, feasibility and effect of exercise among individuals with colorectal cancer. Methods A database search (CINAHL, Ebscohost, MEDLINE, Pubmed, ProQuest Health and Medical Complete, ProQuest Nursing, Science Direct) for randomised, controlled, exercise trials involving individuals with colorectal cancer, published before January 1, 2020 was undertaken. Safety (adverse events), feasibility (withdrawal and adherence rates) and effect data (health outcomes including quality of life, QoL) were abstracted. Risk difference (RD) and standardised mean differences (SMD) were calculated to compare safety and effects between exercise and usual care (UC). Subgroup analyses were conducted to assess whether outcomes differed by exercise mode, duration, supervision and treatment. Risk of bias was assessed using the Physiotherapy Evidence Database tool. Results For the 19 trials included, there was no difference in adverse event risk between exercise and UC (RD = 0.00; 95% CI:-0.01, 0.01,p = 0.92). Median withdrawal rate was 12% (0-22%) and adherence was 86% (42-91%). Significant effects of exercise compared to UC were observed for QoL, fatigue, aerobic fitness, upper-body strength, depression, sleep and reduced body fat (SMD = 0.21-0.66,p < 0.05). Subgroup analyses suggested larger benefits (p < 0.05) for QoL and fatigue for supervised interventions; for QoL, aerobic fitness and reduced body fat for >= 12-week interventions; and for aerobic fitness when interventions were during chemotherapy. Conclusion Although reporting of safety and compliance data was lacking in most trials, findings support that exercise is safe and feasible in colorectal cancer. Further, participation in mixed-mode exercise, including unsupervised exercise, leads to improvements in various health-related outcomes.