Prognostic value of neutrophil to lymphocyte ratio for gastric cancer

Background: Although the prognostic value of the neutrophil to lymphocyte ratio (NLR) in gastric cancer (GC) patients has been investigated by many studies, the results are heterogeneous. The objective of this systematic review is to ascertain the prognostic value of NLR in GC patients. Methods: PubMed and Embase were retrieved to identify potential studies published before 8 June, 2014. Newcastle-Ottawa Scale (NOS) for cohort study was used to assess the quality of all eligible studies. Results: Of the 20 studies included in this systematic review, 17 studies investigated the effect of NLR on overall survival (OS), 11 studies reported that NLR negatively affected OS in their multivariante analysis, and 16 studies reported that NLR negatively affected OS in univariate analysis. Three studies investigated the effect of NLR on progression-free survival (PFS), reporting that increased NLR was associated with worse PFS. Four studies investigated the effect of NLR on disease-free survival (DFS), two of which reported that increased NLR was associated with worse DFS. Two studies investigated the effect of NLR on disease special survival (DSS), but neither observed any significant association between NLR and DSS. The major design deficiencies of the studies available were retrospective data collection, inadequacy of follow-up cohorts, and unavailability of the method used for outcome assessment. Conclusions: Based on the above findings, we conclude that NLR may be a useful prognostic index (PI) for GC. In addition, future studies with prospective design, long-term follow-up and fully adjusted confounding factors are needed to rigorously assess the prognostic value of NLR for GC.