Body composition and physical activity as predictors of immune-related adverse events in patients undergoing cancer immunotherapy: a systematic review

Host factors may affect immune-related adverse events (irAE) during immune checkpoint inhibitor (ICI) therapy. We systematically reviewed studies on body composition (BMI, CT/DXA-defined sarcopenia, sarcopenic obesity) and physical activity (PA) in relation to irAE incidence and severity in ICI-treated adults. PubMed, Embase, Scopus, and Web of Science were searched from inception to 15 December 2024. Eligible studies assessed baseline body composition and/or PA in relation to irAE. Risk of bias was evaluated using the NIH tool and QUIPS. Findings were synthesized using structured narrative methods. Seven studies (2,590 patients) were included. Two large cohorts found overweight/obese patients had higher odds of any-grade irAE (OR = 1.4–1.5); one disease-specific cohort found no association. One CT-based study showed higher irAE risk with sarcopenia (OR = 2.64) and more with sarcopenic obesity (OR = 5.50). Two studies on PA were conflicting: one found higher PA reduced severe irAE risk (OR = 0.19), another found no association. Body composition and PA may help predict irAE in ICI-treated patients. Evidence is low to very low certainty: overweight/obesity may increase toxicity risk, higher PA may lower risk, and evidence for sarcopenia is limited. Standardized prospective studies are needed to confirm these associations. https://www.crd.york.ac.uk/PROSPERO identifier is CRD420251084119.