Serum VEGF Per Platelet Count as a Prognosis Predicting Factor in Advanced Gastric Cancer Patients

Background: New blood vessel formation is a crucial step in the process of tumor growth and systemic metastasis. Recent studies have shown that VEGF expression not in tissues but in serum sample is correlated with tumor vascularity, and the high serum VEGF levels could predict poor prognosis in cancer patients. However there has been no data regarding the clinical and prognostic significance of serum VEGF levels per platelet count in advanced gastric cancer. In this study, we conducted a study to evaluate the prognostic implication of serum VEGF per platelet count in the patients with advanced gastric cancer.

Methods: 111 patients with histologically confirmed gastric cancer, 35 patients with early gastric cancer were included and control serum samples were acquired from 25 healthy volunteers. The levels of VEGF were measured using human VEGF quantitative enzymelinked immunosorbent assay (ELISA). Survival curves were calculated using the Kaplan-Meier method and survival comparisons were made by the log rank test in metastatic gastric cancer. The Cox proportional hazards regression model was utilized for multivariate analyses after univariate analysis defined relevant prognostic variables.

Results: The mean serum VEGF level was higher in the patients of AGC compared to those with EGC and controls (AGC 465 ± 315.8pg/ml; EGC 306 ± 97.8 pg/ml controls 230.8 ± 53.2 pg/ml, P< 0.033). A trend toward a significant positive correlation between serum VEGF and platelet counts was observed in patients of AGC (r = 0.477, P = 0.000, Fig 2) and there was a significant correlation between serum VEGF levels and differentiation of tumor (p = 0.014), stage (p = 0.036). The overall survival (log rank, p =0.0432) and the progression free survival (median 4.5 vs. 8.9 months; log rank, p =0.0116) were significantly shorter in patients with high VEGF per platelet count (≥1.626 pg/10⁶). In the multivarivate analysis, performance status (P=0.025), the presence of peritoneal carcinomatosis (P=0.006), serum VEGF per platelet (P=0.005) were found to be significantly associated with the short progression free survival

Conclusions: This study demonstrated that serum VEGF per platelet count is correlated with short overall survival and progression free survival in advanced gastric cancer patients. Therefore, serum VEGF per platelet may be a useful marker for predicting the prognosis of advanced gastric cancer patients.