Abstract
PURPOSE: Vascular endothelial growth factor (VEGF) is considered as the best-validated key regulator of angiogenesis, while the prognostic role of circulating VEGF in lung cancer remains controversial. We conducted a meta-analysis to evaluate the prognostic role of circulating VEGF. METHODS: Nineteen studies with a total number of 2,890 patients were analyzed in our meta-analysis. Hazard ratios (HRs) and their 95 % confidence intervals (CIs) were used to quantify the predictive ability of circulating VEGF on survival. RESULTS: The pooled HR of all 17 studies evaluating overall survival (OS) was 1.29 (95 % CI 1.19-1.40, p < 0.001), indicating high circulating VEGF predicted poor OS. When grouped by disease stages, the pooled HRs were 0.97 (95 % CI 0.47-1.47, p < 0.001) for operable stage and 1.34 (95 % CI 1.18-1.49, p < 0.001) for inoperable stage. The pooled HRs were 1.28 (95 % CI 1.15-1.42, p < 0.001) for serum and 1.31 (95 % CI 1.13-1.49, p < 0.001) for plasma, when categorized by blood sample. Meta-analysis of circulating VEGF related to progression-free survival (PFS) was performed in 7 studies, and the pooled HR was 1.03 (95 % CI 0.96-1.09). CONCLUSIONS: Our results indicate that high level of circulating VEGF predicts poor OS in lung cancer, yet it does not predict poor PFS.