Impact of Sarcopenia and Obesity on Overall Survival in Patients with Head and Neck Cancer Receiving Radiotherapy: a Longitudinal Study

Purpose: To analyze the impact of sarcopenia and obesity on overall survival (OS) in patients with head and neck cancer (HNC) receiving radiotherapy (RT). Methods: This prospective longitudinal study recruited 494 patients using convenient sampling. Weight and body composition were assessed before RT (T-1), and at the end of RT (T-2) using bioelectrical impedance analysis (BIA). The appendicular skeletal mass index was used to define sarcopenia, while the body mass index and fat mass index were used to define obesity. Patient OS was followed and described using Kplan-Meier analysis. Cox proportional hazard regression was used to analyze influencing factors of OS. Results: The median follow-up time was 26.2 months (IQR: 18.4-34.4 months). Multivariable models indicated that sarcopenia/obesity type assessed at T-1 was not significantly associated with OS. Multivariable models involving body composition at T-2 showed that age (P < 0.001), tumor site (P = 0.003), tumor stage (P = 0.024), and sarcopenia/obesity type (P = 0.040) were significantly associated with OS, while sarcopenic patients without obesity at T-2 had worse OS. Conclusions: Patients with sarcopenia and no obesity at the end of RT might have worse OS. Healthcare professionals should enhance HNC patients' management during RT, helping them maintain a certain amount of muscle mass and fat mass to improve their survival.