Prognostic implication of antitumor immunity measured by the neutrophil-lymphocyte ratio and serum cytokines and angiogenic factors in gastric cancer

Abstract

The neutrophil-lymphocyte ratio (NLR) is associated with a poor prognosis in many cancers but the biological mechanisms involved are unknown. Since cytokines and angiogenic factors (CAFs) are reflected by various immune responses, we analyzed the association between the NLR and CAFs and their prognostic implications in gastric cancer (GC). Of 745 GC patients who were enrolled in NLR analysis, 70 underwent NLR and CAF association analyses. Pretreatment serum levels of 52 CAFs were measured by means of multiplex bead immunoassays and enzyme-linked immunosorbent assays. Linear regression analysis and survival analysis of the NLR with each CAF were performed. Metastatic organ numbers and carbohydrate antigen 19-9 levels were significantly higher in patients with a high NLR [greater than 2.42 (median): P = 0.047 and P < 0.001 respectively]. The overall survival was significantly worse in the high NLR group (17.8 months vs 11.2 months, P < 0.001). In CAF analysis, osteopontin (R (2) = 0.337, P < 0.001) and interleukin-6 (R (2) = 0.141, P = 0.001) were significantly associated with the NLR. Stromal-cell-derived factor 1 (SDF-1) was a significant poor prognostic factor independently of the NLR. Consideration of both the NLR and SDF-1 divided patient groups with different overall survival (both low, 21.0 months; either high, 15.8 months; both high, 8.2 months). The NLR is a significant poor prognostic factor in advanced GC. The NLR is mainly associated with osteopontin and interleukin-6. Besides the NLR, SDF-1 is an independent poor prognostic factor in GC. Consideration of both the NLR and SDF-1 might give insights into antitumor immunity in GC.