Prognostic Significance of MRI-defined Sarcopenia in Patients with Nasopharyngeal Carcinoma: A Propensity Score Matched Analysis of Real-World Data.

Background and purpose: Image-defined sarcopenia is linked to increased mortality among patients with cancer. Nevertheless, its effect on patients with nasopharyngeal carcinoma (NPC) is incompletely established. This study's aim was to investigate the prognostic significance of MRI-defined sarcopenia on the survival of patients undergoing concurrent chemoradiotherapy (CCRT) +/- inducing chemotherapy (IC) for NPC treatment.Methods: 1,307 patients with stage II-IVa NPC were included in this retrospective study. Sarcopenia was defined using skeletal muscle index (SMI) determined through baseline MRI at the C3 level. The association of sarcopenia with overall survival (OS) and progression-free survival (PFS) was assessed by Cox regression models using 1:1 propensity score matching (PSM) analysis. We also conducted a stratification analysis using BMI and treatment strategies.Results: Sarcopenia was an independent risk factor for both OS and PFS (all P < 0.05). However, BMI was not substantially linked to OS and PFS (all P > 0.05). Sarcopenic patients showed lower rates of OS (HR = 2.00, 95% CI: 1.54-2.60, P < 0.001) and PFS (HR = 1.67, 95% CI: 1.35-2.07, P < 0.001) in contrast with nonsarcopenic patients. According to stratification analysis, being overweight was linked to a protective effect in nonsarcopenic patients only. Sarcopenic patients showed similar OS and PFS regardless of the treatment modality.Conclusions: Sarcopenia is underrecognized in NPC patients. Measurement of sarcopenia using routine MRI scans in NPC patients provided significant prognostic information, outperforming BMI. Patients with sarcopenia failed to benefit from an additional IC regimen.(c) 2023 Elsevier B.V. All rights reserved. Radiotherapy and Oncology 188 (2023) 1-8