Pre‐treatment neutrophil‐to‐lymphocyte ratio is an independent prognostic factor in head and neck squamous cell carcinoma: Meta‐analysis and trial sequential analysis

Inflammation seems to play a critical role in the development and progression of different cancers. Neutrophil‐to‐lymphocyte ratio (NLR) is an easily measurable marker of systemic inflammation. The purpose of this systematic review and meta‐analysis was to evaluate the prognostic role of the pre‐treatment NLR, in terms of overall survival (OS) and disease‐free survival (DFS), in patients with primary head and neck squamous cell carcinoma (HNSCC) treated by surgery alone or followed by chemo/radiotherapy. 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. Fixed‐effect models were used on the basis of the presence of heterogeneity. Risk of bias assessment and trial sequential analysis (TSA) were also performed; the quality of the evidence was evaluated via the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. The analysis revealed that a higher value of pre‐treatment NLR correlates with a statistically significant decrease of OS (HR, 1.56; 95% CI: [1.35, 1.80]; p < 0.00001) and a lower DFS (HR, 1.64; 95% CI: [1.30, 2.07]; p < 0.0001) in HNSCC patients.