Skeletal muscle health in childhood cancer survivors: a systematic review and meta-analysis

PURPOSE: Childhood cancer survivors (CCS) are at risk of long-term skeletal muscle deficits following intensive therapies during critical periods of growth. This review aimed to synthesize approaches for assessing muscle quantity, quality, and function in CCS and to quantify deficits relative to healthy peers. METHODS: A systematic search was conducted in CINAHL, Embase, PubMed, SPORTDiscus, and Web of Science from inception to June 2024, with an update in November 2025. Studies including CCS who had completed cancer treatment and reported measures of muscle quantity, quality, or physical function were eligible. A three-level mixed-effects model meta-analysis was conducted. Associations between muscle quantity and function and potential moderators were tested using meta-regression models. Methodological quality was assessed using the Newcastle-Ottawa Scale. RESULTS: Forty-four studies comprising 5175 CCS were included. Compared to controls, CCS exhibited significantly lower muscle quantity (SMD -0.45; 95% CI -0.63 to -0.28; p < 0.001) and muscle function (SMD -0.41; 95% CI -0.57 to -0.24; p < 0.001). No studies evaluated muscle quality. Deficits in muscle function were more pronounced in the lower body than the upper body, and meta-regression analyses indicated greater muscle quantity deficits with increasing time since treatment completion. CONCLUSION: Childhood cancer survivors exhibit significant deficits in muscle quantity and function. Future research should focus on developing international consensus guidelines for standardized, clinically meaningful assessments that include lower-body function and muscle quantity. Additionally, investigating muscle quality may lead to a better understanding of the mechanisms underlying these deficits and help inform targeted interventions aimed at preserving long-term health in CCS.