The prognostic value of vascular endothelial growth factor in patients with renal cell carcinoma: a systematic review of the literature and meta-analysis

Objective: Vascular endothelial growth factor (VEGF) serum level or tumor expression may be prognostic in renal cell carcinoma (RCC). The purpose of this meta-analysis was to examine the prognostic value of serum VEGF level and tumor expression in patients with RCC. Methods: PubMed and EMBASE databases were searched until September 26, 2016. Prospective and retrospective studies of RCC patients that had VEGF levels measured were included. Outcome measures were overall survival (OS), disease-specific survival (DSS), and progression-free survival (PFS). Results: A total of 14 studies were included in the meta-analysis. In patients with RCC, elevated serum VEGF level was not associated with OS (pooled hazard ratio [HR] = 1.16; 95% confidence interval [CI]: 0.52 to 2.60; p = 0.716), but was associated with poor DSS (pooled HR = 4.22; 95% CI: 2.02 to 8.79; p < 0.001) and PFS (pooled HR = 1.50; 95% CI: 1.22 to 1.85; p < 0.001). Removal of one study, however, resulted in elevated serum level being associated with poorer OS. Tumor VEGF expression was not associated with OS (pooled HR = 1.48; 95% CI: 0.74 to 2.95; p = 0.263), but was associated with worse DSS (pooled HR = 1.83; 95% CI: 1.24 to 2.71; p = 0.003). Conclusion: In patients with RCC, elevated serum VEGF level is associated with worse OS, DSS, and PFS, while tumor expression is only associated with worse DSS. The number of studies, however, was limited and the results should be interpreted with caution.