Prognostic Role of Neutrophil/Lymphocyte Ratio in Resected Gastric Cancer: A Systematic Review and Meta-analysis

High levels of inflammatory markers and the neutrophil-lymphocyte ratio appear to be associated with worse overall survival in solid tumors. However, few studies have analyzed the role of the neutrophil-lymphocyte ratio in gastric cancer patients scheduled to undergo curative resection. In the present study, a systematic review and meta-analysis was performed to analyze the relationship between the neutrophil-lymphocyte ratio and overall survival in patients with gastric cancer submitted to curative resection and to identify the clinicopathological features (age, gender, tumor depth, nodal involvement and tumor differentiation) that are correlated with high neutrophil-lymphocyte ratios. A literature search of PubMed, Scopus, Cochrane and EMBASE through November 2017 was conducted. Articles that included gastric cancer patients submitted to curative resection and preoperatory neutrophil-lymphocyte ratio values were included. A total of 7 studies comprising 3264 patients from 5 different countries were included. The meta-analysis revealed an association of high neutrophil-lymphocyte ratios with older age, male gender, lower 5-year overall survival, increased depth of tumor invasion, positive nodal involvement but not with histological differentiation. Evaluation of the neutrophil-lymphocyte ratio is a cost-effective method that is widely available in preoperatory settings. Furthermore, it can effectively predict prognosis, as high values of this biomarker are related to more aggressive tumor characteristics. This ratio can also be used to stratify risk in patients within the same disease stage and may be used to assist in individualized follow-up and treatment.