The effects of exercise on the bone health of people with cancer: a systematic review and meta-analysis

Purpose To determine the pooled effect of exercise on the bone health of people diagnosed with cancer. Methods Four electronic databases were systematically searched. Controlled trials that assessed the effect of exercise on the bone mineral density (BMD) or content (BMC) measured by dual-energy x-ray absorptiometry or peripheral quantitative computed tomography in people who had been diagnosed with cancer were included in the study. Random-effect meta-analyses of effect size (ES) were conducted. Sub-group analyses were performed to explore the influence of intervention duration, prescription and participant characteristics. Results Of 66 full-text articles screened, 22 studies, from 21 interventions, were included (primarily breast/prostate cancer, sample range n = 36-498). When all interventions were grouped, a significant pooled ES was observed for exercise on hip (ES = 0.112, 95% CI: 0.026 to 0.198; p = 0.011) and lumbar spine BMD (ES = 0.269, 95% CI: 0.036 to 0.501; p = 0.024) compared to control. There was also an influence of sex, where females had greater improvements in hip (ES = 0.120, 95% CI: 0.017 to 0.223; p = 0.022) and spine BMD (ES = 0.415, 95% CI: 0.056 to 0.774; p = 0.23) compared to males. Conclusion Overall, exercise regimens of studies included in this review appear to improve bone health at the hip and spine in people diagnosed with cancer. Sub-analyses suggest some influence of sex, where females had greater improvements in BMD compared to males. It is essential that future studies evaluate the dose-response of exercise training on bone health and create exercise protocols that better align with the laws of bone modelling to enhance osteogenic potential.