Association between muscle mass evaluated by computed tomography and the serum creatinine-cystatin C ratio in children with cancer: A cross-sectional study

Objective: There is limited knowledge about muscle-mass loss in childhood and adolescent patients with cancer. The aim of this study was to investigate the association between muscle mass evaluated by computed tomography (CT) and the serum creatinine-cystatin C ratio (CCR) in children and adolescents with cancer. Methods: Patients age <18 y with cancer who underwent abdominal CT scans and blood sampling for serum creatinine and cystatin C within 1 wk before or after the CT scan between 2017 and 2019 at our hospital were retrospectively enrolled. A measurement was defined as a set of abdominal CT scans and serum creatinine and cystatin C levels. The psoas muscle cross-sectional area (PMCSA) was defined as the psoas major muscle area at the level of the fourth lumbar vertebra on axial CT. Statistical tests and modeling were performed as measurement-based analyses. Results: A total of 109 patients and 204 measurements were included in the analysis. CCR showed a strong positive correlation with PMCSA (r = 0.75; P < 0.001). The association between CCR and PMCSA was observed in all age groups and both sexes. There was a clear trend of increased PMCSA across quartile categories of CCR (P < 0.001). On multivariate, generalized, estimating, equation, linear regression model analysis, examining factors associated with PMCSA, male sex, body surface area, and CCR were independent parameters for PMCSA. Conclusions: These results suggest that CCR may be a useful surrogate marker for muscle mass in cancer care for children and adolescents. (C) 2022 Elsevier Inc. All rights reserved.