Effect of exercise on bone-related outcomes in patients with cancer affected by bone metastases or bone loss: a systematic review and meta-analysis.

INTRODUCTION

This systematic review and meta-analysis aimed to evaluate the effects of exercise interventions on bone mineral density (BMD), bone mineral content (BMC), and bone turnover markers in patients with cancer and compromised bone health.

MATERIALS AND METHODS

A comprehensive search of four electronic databases was conducted to identify randomized controlled trials evaluating the effect of exercise intervention compared to supplementation or bone-targeted agents only on BMD, BMC and bone turnover markers. Meta-analyses were performed using random-effects models to calculate effect sizes (ES) with 95% confidence intervals (CI).

RESULTS

Eighteen studies were included, involving 1,478 patients with mainly breast and prostate cancer. Meta-analyses of 11 trials showed no significant effect of exercise on whole-body (ES: 0.16, 95% CI: -0.10 to 0.41; p = 0.23), lumbar spine (ES: 0.10, 95% CI: -0.03 to 0.24; p = 0.14), hip (ES: -0.06, 95% CI: -0.77 to 0.64; p = 0.86), or femoral neck (ES: 0.07, 95% CI: -0.08 to 0.21; p = 0.37) BMD. However, individual studies reported improvements in lumbar spine and hip BMD following resistance or high-impact training. In patients with bone metastases, resistance training increased BMD at metastatic vertebrae. Bone turnover markers showed mixed trends, with some studies reporting increased bone formation and reduced resorption, especially after 3 months of intervention.

CONCLUSIONS

Our results suggest that, while exercise does not significantly increase BMD in patients with cancer and bone impairments when added to standard therapies, there are important variations across studies. High-intensity resistance and impact-loading training may be beneficial for specific bone sites and patient subgroups. Further research is warranted to identify optimal exercise modalities tailored to cancer type, treatment stage, and bone health status, including feasibility for patients with bone metastases.