Microvessel density as a prognostic factor in bladder cancer: A systematic review of literature and meta-analysis

BACKGROUND: Many studies have shown that microvessel density (MVD) could play a potential value as prognostic biomarkers of tumors. The aim of this systematic review and meta-analysis is to evaluate the association between MVD and survival in patients with bladder cancer. METHODS: Relevant literature was identified using PubMed and EMBASE. The eligible studies were assessed for quality using REMARK (REporting recommendations for tumor MARKer prognostic studies (REMARK)). The patients' clinical characteristics and survival outcomes in eligible studies were extracted. And then, data were synthesized to evaluate the prognostic role of the MVD in bladder cancer with hazard ratio (HR), while the heterogeneity among studies was examined using the I-2. RESULTS: This meta-analysis included 10 eligible studies conducted between 1998 and 2011 dealing with bladder cancer. The combined HRs and 95% confidence interval [95% CI] for disease-free survival (DFS) was 2.24 [1.20,4.17], for overall survival (OS) was 1.16 [1.02,1.33] and 1.68 [1.15,2.45] for disease-specific survival (DSS). There was evidence heterogeneity between studies, and the disease stage was a key factor for heterogeneity in subgroup analysis. CONCLUSIONS: Our studies suggested that high MVD was significantly associated with poor survival and MVD could serve as a prognostic biomarker in patients with bladder cancer.