Impact of muscle loss in children with hematologic malignancies undergoing allogeneic hematopoietic cell transplantation

The widespread recognition of the concept of sarcopenia, or muscle loss, has impacted the prognosis of patients undergoing high-intensity treatments. We focused on the effect of muscle loss on the prognosis of pediatric patients with hematologic diseases. A total of 65 patients with hematologic malignancies who underwent allogeneic HCT once were investigated. The change in cross-sectional psoas muscle area (PMA) measured on computed tomography (CT) images was expressed as the muscle loss index (MLI), which was calculated by dividing the pre-HCT PMA by the baseline PMA. In this study, patients with MLI values less than 0.85 were classified into the muscle loss group. Muscle loss was observed in 27 patients (41.5%). Patients who experienced muscle loss were older than those who did not. Muscle loss was an independent predictor of higher non-relapse mortality (NRM) (p = 0.012) and inferior overall survival (OS) (p = 0.045) at 5 years. Multivariate analysis showed that muscle loss was an independent risk factor for higher NRM (p = 0.046), and inferior EFS (p = 0.048). Muscle loss observed pre-HCT may be a predictor of increased NRM, poor OS and EFS in pediatric patients with hematologic malignancies undergoing allogeneic HCT.