Prognostic Impact of Sarcopenia’s Occurrence during Radiotherapy in Oropharyngeal Cancer Patients

SIMPLE SUMMARY: Several retrospective studies have shown worse oncological outcome and toxicity in sarcopenic patients with head and neck cancer undergoing radiotherapy. The current study focuses on patients with oropharyngeal carcinoma, especially HPV-associated, to investigate whether sarcopenia, not only present at baseline before starting treatment, but also arising during radiotherapy, could impact oncological outcomes and toxicity in these good-prognosis patients. Indeed, the intensification of a tailored approach with prompt nutritional intervention, trying to intercept patients before the onset of sarcopenia, could improve oncological outcomes. ABSTRACT: The current study aims to profile sarcopenic condition (both at baseline and developed during treatment) in oropharyngeal carcinoma (OPC) patients treated with curative radiotherapy (RT) +/− chemotherapy and to evaluate its impact on oncological outcomes and toxicity. A total of 116 patients were included in this retrospective single-center study. Sarcopenia assessment at baseline and at 50 Gy re-evaluation CT was obtained from two different methodologies: (i) the L3-skeletal muscle index (SMI) derived from the contouring of the cross-sectional area (CSA) of the masticatory muscles (CSA-MM); and (ii) the paravertebral and sternocleidomastoid muscles at the level of the third cervical vertebra (CSA-C3). Based on L3-SMI from CSA-MM, developing sarcopenic condition during RT (on-RT sarcopenia) was associated with worse progression-free survival (PFS) (p = 0.03) on multivariable analysis and a trend of correlation with overall survival (OS) was also evident (p = 0.05). According to L3-SMI derived from CSA-C3, on-RT sarcopenia was associated with worse PFS (p = 0.0096) and OS (p = 0.013) on univariate analysis; these associations were not confirmed on multivariable analysis. A significant association was reported between becoming on-RT sarcopenia and low baseline haemoglobin (p = 0.03) and the activation of nutritional counselling (p = 0.02). No significant associations were found between sarcopenia and worse RT toxicity. Our data suggest that the implementation of prompt nutritional support to prevent the onset of sarcopenia during RT could improve oncological outcomes in OPC setting.