Clinicopathological characteristics of vascular endothelial growth factor expression in uveal melanoma: A meta-analysis

Angiogenesis is a potential prognostic factor that has been extensively investigated in patients with uveal melanoma (UM). Vascular endothelial growth factor (VEGF) expression is crucial in angiogenesis. However, there have been conflicting data regarding the clinicopathological data in UM. A meta-analysis was performed of all the germane literature to assess the clinicopathological characteristics of VEGF expression by combining separately estimated odds ratio (OR) values. Our combined results demonstrated that, according to the available studies, the expression of VEGF in UM was significantly higher compared to normal tissue [338 patients and 99 controls; OR=16.15, 95% confidence interval (CI): 8.65-30.12, P<0.00001]. When stratifying the studies by age (315 patients; OR=2.08, 95% CI: 1.19-3.62, P=0.01), cell type (423 patients; OR=0.54, 95% CI: 0.32-0.90, P=0.02), tumor size (222 patients; OR=0.30, 95% CI: 0.14-0.68, P=0.004) and scleral invasion (248 patients; OR=0.34, 95% CI: 0.15-0.78, P=0.01), significant clinicopathological information was provided. Our results indicated that VEGF expression in UM patients was significantly higher compared to that observed in controls. It was also significantly higher in patients who presented with scleral invasion and those who were aged <50 years. In addition, VEGF expression was higher in mixed-cell type and epithelioid-cell type UM and in patients with large-sized tumors.