Home-based Exercise Training Reduces Tnf-α During Treatment For Metastatic Castration-resistant Prostate Cancer

Exercise training serves as a potential mechanism to mitigate side effects of androgen receptor signaling inhibitors (ARSI) for metastatic castration-resistant prostate cancer (mCRPC). Previously, supervised exercise programs have reduced circulating pro-inflammatory cytokine levels in localized prostate cancer patients, most notably with changes in TNF-α and C-reactive protein. Although a more feasible option, it is unknown if home-based interventions may produce similar benefits in circulatory biomarkers associated with tumor progression. PURPOSE: To investigate the impact of a 12-week home-based exercise intervention on inflammatory responses within men with mCRPC on ARSI. METHODS: 16 men with mCRPC (age: 71 ± 8y, height: 172.4 ± 4.6 cm, mass: 86.2 ± 19.6 kg) had resting blood samples drawn and inflammatory cytokine profiles assessed prior to and after undergoing a 12-week home-based exercise intervention using resistance bands and walking. Exercise adherence, determined by the number of completed sessions relative to the total prescribed, was calculated for group development relative to the original study target (High: ≥75%; Low: <75%). Changes (∆) with training (Pre vs. Post) and between adherence (High vs. Low) were assessed using t-tests (p ≤ 0.05). RESULTS: All 16 mCRPC patients completed the entire exercise intervention with adherence rates of 80%, 63%, and 72% for walking, resistance training, and overall adherence, respectively. Overall, circulating TNF-α levels decreased by 1.6% at Post (0.9 ± 2.6 pg·mL-1, p = 0.020). Adherence assessments resulted in no group differences in TNF-α for total (0.1 ± 0.8 pg·mL-1, p = 0.864), walking (0.1 ± 0.8 pg·mL-1, p = 0.864), or resistance training (0.5 ± 0.7 pg·mL-1, p = 0.07). No changes were reported in any other inflammatory outcomes. CONCLUSION: Reductions in TNF-α expression were observed following home-based exercise in men with mCRPC. When paired with the maintained expression of anti-inflammatory cytokines, these changes may have benefits regarding PC progression, although this needs further testing. However, similarities in TNF-α expression were observed regardless of self-reported exercise adherence which may indicate alternative beneficial mechanisms of interest besides exercise training.