Prognostic Significance of Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio in Oncologic Outcomes of Esophageal Cancer: A Systematic Review and Meta-analysis

Background Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been reported to predict oncologic outcomes in patients with various types of cancer. However, their prognostic value in patients with esophageal cancer is unclear. In this meta-analysis, we evaluated the prognostic significance of NLR and PLR in esophageal cancer patients. Methods We performed comprehensive searches of electronic databases to identify studies that evaluated the prognostic impact of pretreatment NLR and PLR in esophageal cancer patients. The end points were overall survival (OS), disease-free survival, and clinicopathologic parameters. A meta-analysis using random-effects models was performed to calculate hazard ratios (HRs) or odds ratios with 95 % confidence intervals (CIs). Results Seven retrospective, observational, cohort studies involving 1540 patients were included. All seven studies evaluated NLR, and four evaluated PLR. Both high NLR (HR 1.40, 95 % CI 1.08–1.81, P = 0.01) and high PLR (HR 1.59, 95 % CI 1.14–2.21, P = 0.006) were significantly predictive of poorer OS. NLR was not a significant predictor of disease-free survival. High PLR (HR 1.85, 95 % CI 1.50–2.28, P