Systematic Review and Meta-Analysis of the Prognostic Significance of Neutrophil-Lymphocyte Ratio (NLR) After R0 Gastrectomy for Cancer

PURPOSE: A meta-analysis was performed to evaluate the prognostic value of neutrophil-lymphocyte ratio (NLR) in patients undergoing potentially curative gastrectomy for cancer (GC). METHODS: Thomson Reuters Web of Science, Ovid MEDLINE(R) and PUBMED databases were searched for relevant articles using search terms neutrophil-lymphocyte ratio (NLR), GC and survival. Articles reporting overall survival (OS), cancer-specific survival and disease-free survival (DFS), in patients undergoing R0 gastrectomy, were studied. RESULTS: Articles numbering 365 were identified during the preliminary search, and 10 containing 4164 patients were included in the final review. Most patients were > 60 years of age, male (67%) and 2239 (53.8%) had pT3 disease. The number of NLR dichotomization thresholds reported numbered 7, with 2.00 and 3.00 (n = 2) the most common. NLR was associated with poor survival in eight studies with hazard ratios ranging from 1.54 (95% confidence interval (CI) 1.26–1.89) to 2.99 (1.99–4.49). Pooled odds ratio (OR) for OS was 2.31 (1.40–3.83, p = 0.001) and for DFS 2.72 (1.14–6.54, p = 0.020). Four studies presented T-stage data, OR 1.62 (1.33–1.96, p < 0.001). CONCLUSION: NLR is an important prognostic indicator associated with both OS and DFS after R0 resection of GC, but the critical level is equivocal.