Across 21 randomised controlled trials encompassing up to 5,492 cancer patients, structured exercise interventions were associated with a 23% reduction in overall survival hazard (HR 0.77), a 17% improvement in disease-free survival (HR 0.83), an 18% reduction in all-cause mortality (RR 0.82), and a striking 26% reduction in cancer-specific mortality (RR 0.74). GRADE certainty was rated moderate for all four primary endpoints. Subgroup analyses flagged aerobic exercise, higher adherence, and early-stage disease as drivers of the most pronounced benefit.
This is among the most rigorous aggregations of RCT-level evidence to date on exercise as oncological therapy — and the findings are genuinely striking. For decades, exercise in cancer care has been justified on quality-of-life grounds; this meta-analysis shifts the conversation toward survival itself. A 23% hazard reduction in overall survival from a behavioural intervention rivals some adjuvant pharmacological agents, making these numbers clinically consequential if they hold up.
Important caveats apply. Moderate GRADE certainty means residual confounding and heterogeneity remain concerns — RCTs in this space vary enormously in cancer type, stage, exercise modality, and duration. The absence of benefit for progression-free survival and pathological complete response is puzzling and may reflect mechanistic limits or insufficient trial power. Adherence-dependence also signals a real-world implementation challenge.
For healthy adults and cancer survivors alike, the practical takeaway is powerful: structured aerobic exercise should be treated as a serious adjuvant strategy, not a lifestyle add-on. Oncologists and GPs have grounds to prescribe it proactively.
