A meta-analysis of 21 randomized controlled trials, discussed on the TTHealthWatch podcast, found that structured exercise after cancer treatment improved overall survival by 23% and reduced cancer-specific mortality by 26%. The analysis included nearly 8,500 participants and also showed smaller benefits for disease-free survival and all-cause mortality.
The authors rated the evidence as moderate for overall survival, disease-free survival, cancer-specific mortality, and all-cause mortality. Benefits were more pronounced in participants with higher adherence to exercise, those doing aerobic exercise, and those with early-stage disease. The majority of participants were women with breast cancer, and the podcast hosts noted that more diverse cancer types and stages are needed.
The researchers also proposed mechanisms: exercise may improve infiltration of cytotoxic T cells and natural killer cells into tumors, enhance drug penetration through increased circulation, and increase glucose uptake in skeletal muscle, depriving tumors of nutrients. The hosts noted that time since diagnosis was rarely reported across trials and should be included in future studies.