Lack of association of microvessel density with prognosis of renal cell carcinoma: evidence from meta-analysis.

To investigate microvessel density (MVD) and its association with prognosis of renal cell carcinoma (RCC) by means of a meta-analysis. We obtained published studies and extracted appropriate data, then did a meta-analysis to estimate the predictive role of MVD by combining estimated effect-size from individual studies. Analyses for overall survival (OS) and cancer-specific survival (CSS) were performed, separately. Subgroup analysis stratified by biomarkers were also performed for studies using CD34, factor VIII-related antigen (F VIII) and others, respectively. A total of 20 studies were included for meta-analyses including nine (four for F VIII, three for CD34, and two for others) for OS and 11 (two for F VIII, seven for CD34 and two for others) for CSS. There was no significance of MVD predicting OS or CSS of RCC. The pooled HR for OS was 0.910 (95% CI 0.824-1.006; P = 0.065) and CSS was 0.977 (95% CI: 0.915-1.043; P = 0.487). We failed to observe significant association between MVD and prognosis of RCC. Additional studies are needed to provide more precise evidences to support our results.