Prognostic role of neutrophil–lymphocyte ratio in esophageal cancer: A systematic review and meta-analysis

BACKGROUND: The prognostic role of neutrophil-to-lymphocyte ratio (NLR) in esophageal cancer (EC) remains controversial. METHODS: The aim of this study was to evaluate the association between NLR and oncologic outcome of EC patients through a meta-analysis. A systematic search was performed in PubMed, Web of Science and Embase for relevant studies. Meta-analysis was performed using hazard ratio (HR) and95% confidence interval (CI) as effect measures. RESULTS: Finally, 33 articles with 11,039patients were included in our study. The synthesized results indicated that the elevated NLR was negatively related to overall survival (OS) (HR = 1.39, 95% CI: 1.23–1.54). When the patients were stratified according to country, pathological type, treatment strategies, sample size, and different HR estimate method, high NLR was also significantly correlated with poor OS. Similarly, elevated NLR was also associated with shorter disease-free survival (DFS), progress-free survival (PFS), relapse-free survival (RFS), and cancer-specific survival (CSS). CONCLUSION: The elevated pretreatment NLR is associated with poor oncological outcomes in patients with EC. NLR may be a significant predictive biomarker in EC. Further large-cohort studies are needed to confirm these findings.