A SYSTEMATIC REVIEW ON THE ROLE OF SARCOPENIA ON OUTCOMES OF CANCER PATIENTS UNDERGOING RADIOTHERAPY

Abstract

The prognostic effect of sarcopenia in cancer patients undergoing surgery and chemotherapy has been evaluated in various studies, but few have focused on radiation therapy (RT). Aim: We investigated the prevalence of sarcopenia and the relationship between sarcopenia and outcomes in older cancer patients who underwent RT without chemotherapy. A systematic review of the literature was performed in the Pubmed/Medline and Cochrane databases in November 2022, where we used the search terms and medical subject headings „sarcopenia“, „low muscle mass (LMM)“, „low muscle strength“, „LMM and low muscle strength“, „LMM and low muscle strength and low physical performance“ and „RT“. Outcomes were overall survival (OS), progression-free survival (PFS), disease-specific survival (DSS) associated with RT. In 460 studies, 8 studies were eligible the inclusion criteria. The prevalence of sarcopenia was between 42.8% and 72%. Sarcopenia was not associated with OS or 3-year OS in seven studies, defined as LMM, and in one study was present as concomitant LMM and low muscle strength/function. There was heterogeneity between studies as there was variation in their inclusion criteria, definition and assessment methods used to detect sarcopenia, cut-offs for LMM and strength considered, crosssectional area imaging locations for muscle mass assessment and included covariates. Inconsistency in study results may also be due to variations in diagnoses, sample size, and treatment options. The low number of included studies and the low number of patients in each study limit generalizability. Conclusions: Sarcopenia may be a negative prognostic factor, especially in OS when low muscle strength or function is integrated into its definition. We suggest that clinicians focus on muscle strength/function while considering muscle mass and the relationship of sarcopenia with cancer and RT-related outcomes.