Reduced Lower Body Muscular Strength and Endurance among Adult Survivors of Childhood Cancer.

Introduction: Impaired physical fitness is a possible late effect among adult survivors of childhood cancer (ASCC). Our study describes lower body muscular strength and endurance among ASCC using the 1-minute sit-to-stand (1-min STS) test, compares them with the general population, identifies risk factors, and describes changes over time.Methods: In a prospective multicenter cohort study, we invited ASCC ≥18 years of age at study, diagnosed between ages 0-20 treated in five pediatric oncology centers across Switzerland from 1976-2017 who survived ≥5 years for a 1-min STS test. We collected information about lifestyle, medical history, and previous cancer treatment. Using population-based Swiss reference values, we calculated age- and sex-adjusted z-scores for 1-min STS performance and assessed the association between risk factors and 1-min STS test using multivariable linear regression. We fitted a multilevel linear model to describe the longitudinal course of 1-min STS performance.Results: We included 338 CCS of 1048 invited ASCC (participation rate 32%) with median age at study of 34 years (interquartile range 26-41). Compared with the general population, mean 1-min STS z-score was half a standard deviation lower (-0.52; 95% CI -0.64 to -0.40). Obesity (B = -0.56; 95% CI -0.97 to -0.16), cumulative cisplatin dose (B = -0.12; 95% CI -0.21 to -0.02), and cumulative cranial radiotherapy dose (B = -0.10; 95% CI -0.19 to -0.01) were associated with reduced 1-min STS performance. There was no change in 1-min STS z-scores over time (B = 0.02; 95% CI -0.05 to 0.09).Conclusions : We found evidence for reduced lower body strength and endurance among ASCC, suggesting the need for counseling and effective training and rehabilitation programs for maintaining daily functioning, improving cardiovascular health, and reducing morbidity for ASCC.