Prognostic and clinicopathologic significance of neutrophil-to-lymphocyte ratio in esophageal squamous cell carcinoma: evidence from a meta-analysis

Purpose: Evidence from an increasing number of studies has demonstrated that the neutrophil-to-lymphocyte ratio (NLR) is a prognostic factor for various cancers. However, it is unclear whether NLR predicts prognosis in esophageal squamous cell carcinoma (ESCC). We conducted a meta-analysis to investigate the prognostic and clinicopathologic significance of NLR in patients with ESCC. Patients and methods: Selected studies were identified by searches in PubMed, Embase, and Web of Science databases and filtered using our prepared criteria. The hazard ratio (HR) and odds ratio were chosen as effect measures to assess the prognostic role of NLR and its clinicopathologic significance in ESCC. In total, nine studies containing 2,513 patients were enrolled. Results: We demonstrated that elevated NLR was associated with worse overall survival in ESCC patients (pooled HR=1.314; 95% confidence interval, 1.164-1.484; P<0.001). Elevated NLR was also associated with unfavorable characteristics regarding depth of tumor invasion, tumor size, clinical stage, and differentiation degree. Conclusion: The results of our meta-analysis suggest that a high NLR value might represent a poor prognosis and worse clinicopathologic characteristics for patients with ESCC.