A retrospective cohort study of physical activity and survival in patients treated with immune checkpoint inhibitors.

BACKGROUND: The impact of physical activity in cancer patients treated with immune checkpoint inhibitors (ICI), both of which affect outcomes via modulating the immune system, is unclear. We investigated associations between self-reported, pre-treatment physical activity and survival in a series of cancer patients treated with ICI. METHODS: This retrospective cohort study included 930 patients treated with ICI who previously reported physical activity and had good performance status at treatment initiation. Hazards of death associated with increasing quartile of physical activity, measured as weekly metabolic equivalent of task (MET) minutes derived from the International Physical Activity Questionnaire (IPAQ), were estimated by multivariable Cox proportional hazard models adjusting for covariates. Alternative measures of physical activity based on IPAQ and consensus guidelines were also assessed. RESULTS: Increasing physical activity quartile was associated with a decreased adjusted hazard of death (aHR per one quartile increase, 0.89; 95% CI 0.82-0.96). Patients in the third and top quartile had a 24% (aHR, 0.76; 95% CI 0.59-0.97) and 28% (aHR, 0.72; 95% CI 0.55-0.93) reduced hazard of death compared to the bottom quartile, respectively. Results based on IPAQ and consensus guidelines and results from sensitivity analyses support findings from main analyses. CONCLUSIONS: Pre-treatment physical activity is associated with increased survival among cancer patients treated with ICI. Observational studies incorporating objective measurement and randomized interventional trials are needed to further establish the role of physical activity in improving ICI outcomes. IMPACT: Physical activity may be a promising interventional strategy to accompany ICI therapy to improve patient outcomes.