Prognostic significance of vascular endothelial growth factor expression in esophageal carcinoma: a meta-analysis.

PURPOSE The purpose of this study was to comprehensively and quantitatively review eligible published studies to explore the prognostic significance of vascular endothelial growth factor (VEGF) expression in patients with esophageal carcinoma (EC). METHODS PubMed and Embase databases were searched until September 11, 2011. A meta-analysis was performed to demonstrate any relationship between VEGF and 5-year overall survival (OS) in EC patients. RESULTS The final analysis included 1453 patients from 19 studies. The studies were grouped by patient source, histology, VEGF isoform and cutoff value. The estimated risk of death suggested that VEGF positivity had negative impact on prognosis of patients with EC, esophageal squamous cell carcinoma (ESCC) and Asian patients. The risk ratios (RR) and 95% confidence interval (95% CI) were 1.26 (1.16-1.37) in EC patients, 1.28 (1.16-1.40) in ESCC patients and 1.35 (1.24-1.48) in Asian patients. Furthermore, when the cutoff value was set at 10% in 6 studies, the RR (95% CI) was 1.48 in the VEGF positive group (1.27-1.73). In addition, VEGFC was also correlated with patient poor prognosis with a RR (95% CI) of 1.30 (1.15-1.48). However, EC patients from non-Asian countries and cutoff value at 30% showed no significant correlation with survival. Data were not sufficient to determine the prognostic value of VEGF expression in esophageal adenocarcinoma (EA) patients and VEGFD expression. CONCLUSIONS VEGF positivity indicated poor prognosis in patients with EC, ESCC and of Asian origin. Cutoff value at 10% may be a more appropriate standard to define VEGF positivity. VEGFC also correlated with poor prognosis in EC patients.