Prognostic significance of MRI-defined sarcopenia in patients with nasopharyngeal carcinoma: A propensity score matched analysis of real-world data

•Sarcopenia was an independent risk factor for overall survival (OS) and progression-free survival (PFS) in nasopharyngeal carcinoma (NPC) patients (stage II-IVa).•Sarcopenia is a better prognosis predictor than body mass index in NPC patients.•Overweight is a protective factor in nonsarcopenic patients.•Sarcopenic patients could not achieve OS and PFS benefits from additional inducing chemotherapy (IC) prior to concurrent chemoradiotherapy (CCRT), suggesting that the IC regimen may be not necessary for NPC patients with sarcopenia. 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. 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. Sarcopenia was an independent risk factor for both OS and PFS (all P 0.05). Sarcopenic patients showed lower rates of OS (HR = 2.00, 95% CI: 1.54–2.60, P