Effect of combined consideration of distinct signatures of VEGF and soluble VEGFR2 on prognostic implication in gastric cancer.

Abstract

56 Background: Anti-angiogenic strategy in gastric cancer (GC) has been highlighted again due to the recent success of ramucirumab and apatinib. Therefore, the comprehensive network of VEGF, soluble VEGF receptor-2 (sVEGFR2) and cytokines and other angiogenic factors (CAF) in GC and their prognostic impact would be of importance, although they have been poorly understood. We aimed to find out the CAF signature associated with VEGF and sVEGFR2, and to explore their prognostic implication in GC. Methods: We measured pretreatment serum levels of 52 CAFs, including VEGF and sVEGFR2, using multiplex bead immunoassays and ELISA, in 70 patients who were diagnosed with GC in Seoul National University Hospital, and treated with palliative chemotherapy. Linear regression analysis for correlating CAFs with VEGF and sVEGFR2, and survival analysis by log rank test and Cox regression analysis were performed. Results: The VEGF signature was shown to be associated with seven CAFs (interluekin [IL]-7, IL-12p70, IL-2Ra, IL-10, stem cell factor, Fibroblast growth factor-basic, IL-3). The sVEGFR2 signature was associated with IL-4 and platelet-derived growth factor beta, but VEGF and sVEGFR2 showed no association with each other. Patients with high VEGF had a tendency to have worse overall survival (OS) than those with low VEGF (11.2 months versus 16.7 months; P = 0.061). However, among patients with high-sVEGFR2, OS was not different according to VEGF (12.1 months, high-VEGF versus 15.1 months, low-VEGF; P = 0.546). Interestingly, the poor prognostic impact of high-VEGF was far significant in patients with low-sVEGFR2 (10.9 months versus 16.8 months; P = 0.036). With this perspective, VEGF/sVEGFR2 ratio was significantly correlated with worse OS in univariate as well as multivariate analysis (HR 1.78 [95% CI 1.08-2.94], P= 0.024). Conclusions: Based on the comprehensive network analysis of CAF, VEGF and sVEGFR2 had distinct CAF signatures in GC. Consideration of both VEGF and sVEGFR2 confers more accurate prognostic implication compared with VEGF alone in GC. Regarding the angiogenic aspect, VEGF/sVEGFR2 ratio is significantly correlated with survival outcome in GC.