Sarcopenia in Children With Wilms Tumor: A Marker of Undernutrition Which May Impact Adversely on Clinical Outcomes.

The therapeutic approach to Wilms tumor (WT) is multidisciplinary and leads to significant patient impairment, increasing the risk of nutritional compromise and malnutrition. Children with cancer are vulnerable to sarcopenia which has been recognized as a negative impact of anticancer therapy. Recent studies have highlighted the reduction in the total psoas muscle area (TPMA) to be associated with a poor prognosis in many pediatric diseases, including cancer. This study aims to evaluate changes in the TPMA compartment during the treatment of children with WT. An observational, longitudinal, and retrospective study was undertaken in a single institution evaluating children (1 to 14 y, n=38) with WT between 2014 and 2020. TPMA was assessed by the analysis of previously collected, electronically stored computed tomography images of the abdomen obtained at 3 time points: diagnosis, preoperatively, and 1 year after surgery. For all patients, TPMA/age were calculated with a specific online calculator. Our data show a high incidence of sarcopenia (55.3%) at diagnosis which increased after 4 to 6 weeks of neoadjuvant chemotherapy (73.7%) and remained high (78.9%) 1 year after the surgical procedure. Using TPMA/age Z-score curves we have found significant and rapid muscle loss in children with WT, with little or no recovery in the study period.