Purpose: This study aimed to explore the effects of exercise on post-treatment colorectal cancer survivors through a systematic review and meta-analysis as the current information is limited and controversial.
Methods: We searched PubMed, Web of Science, Embase, and Cochrane Library databases for randomized controlled trials that focused on exercise intervention for adult colorectal cancer survivors who had completed primary cancer treatment. We extracted and pooled information regarding psychosocial outcomes, physical functions, body composition, metabolic growth factors, and/or tumor-related biomarkers. All data were assessed by two independent reviewers. The risk of bias was assessed using the Cochrane Collaboration's tool.
Results: A total of 20 studies, which presented data from 1223 post-treatment colorectal cancer survivors, matched the inclusion criteria. Compared with usual care or usual lifestyle, exercise intervention increased VO2peak (n = 107, SMD = 0.72, 95% CI = 0.32 to 1.11, I2 = 41%, P = 0.0004), reduced fasting insulin levels and insulin resistance (n = 150, SMD = - 0.55, 95% CI = - 0.88 to - 0.23, I2 = 0%, P = 0.0009; SMD = - 0.62, 95% CI = - 0.95 to - 0.29, I2 = 0%, P = 0.0002), and decreased levels of sICAM-1. Moderate-intensity exercise was associated with a more pro-inflammatory immune state, resulting in increased oxidative DNA damage. However, no evidence was found for effects of exercise on psychosocial outcomes or body composition.
Conclusions: Our results revealed that exercise could be a feasible and effective option for improving cardiopulmonary fitness, metabolism, and tumor-related biomarkers in post-treatment colorectal cancer survivors.
Implications for cancer survivors: Given the benefits of exercise for colorectal cancer survivors, they should be encouraged to become more physically active.
Keywords: Colorectal cancer survivors; Exercise; Post-treatment; Systematic review.