THE PROGNOSTIC ROLE OF PRE-TREATMENT PLATELET-TO-LYMPHOCYTE RATIO IN HEAD AND NECK SQUAMOUS CELL CARCINOMA: META-ANALYSIS AND TRIAL SEQUENTIAL ANALYSIS

Evidence suggests that inflammation contributes to tumor development, from onset to progression and metastasis. Platelet-to-lymphocyte ratio (PLR) is a composite parameter that provides information from two distinct cellular elements, platelets, and lymphocytes. The purpose of this systematic review and meta-analysis is to evaluate the prognostic role of the PLR, in terms of overall survival (OS), disease-free survival (DFS), cancer-specific survival (CSS) and progression-free survival (PFS), in patients with primary head and neck squamous cell carcinoma treated with surgery followed or not by adjuvant therapies.This systematic review was performed according to the guidelines reported in the Cochrane Handbook and the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. Meta-analysis of OS and DFS was performed using the inverse of variance test. Random-effect models were used on the basis of high heterogeneity. Risk of bias assessment, quality of evidence within studies (GRADE) and trial sequential analysis (TSA) were also performed.The analysis revealed that a higher value of pretreatment PLR correlates with a statistically significant decrease of OS (HR, 1.85; 95% CI: [1.23, 2.80]; P < .00001), confirmed by TSA. The meta-analysis reports an association between high PLR and DFS (HR,1.46; 95% CI: [1.03, 2.06]; P = .003); but TSA suggests that it his should be considered as a false positive. Further studies are needed to validate the efficacy of PLR in predicting CSS and PFS outcomes.Pretreatment PLR is an independent prognostic factor for OS in HNSCC.