title: Prognostic value of microvessel density in hepatocellular carcinoma patients: a meta-analysis.
abstract: BACKGROUND
  The identification of microvessel density (MVD) in patients suffering from different types of cancer has become a hot point as an emerging and promising biomarker. The aim of the present study is to clarify the prognostic relevance of MVD in hepatocellular carcinoma (HCC).
  
  
  METHODS
  Relevant articles were screened in PubMed and EMBASE databases. Patients' clinical characteristics, overall survival (OS), disease/recurrence-free survival (DFS/RFS), and MVD levels were extracted for further analysis. The statistical analysis derived from the Kaplan-Meier survival curves was calculated indirectly with the methods developed by Parmar, Williamson, and Tierney. Multivariate Cox hazard regression analysis was used directly in Stata 11.0. The pooled hazard ratio (HR) and 95% confidence interval (CI) were calculated to evaluate the prognostic role of MVD in HCC.
  
  
  RESULTS
  Our online literature search identified 12 articles including a total of 1,138 HCC patients. Meta-analysis of all the included studies considering survival outcomes showed a positive correlation between poor prognosis and higher-MVD levels. The pooled HRs (and 95% CIs) for OS and DFS/RFS were respectively 2.08 [1.77-2.45] and 2.64 [2.12-3.29]. Subgroup analyses considering tumor stage (I-II/III-IV), tumor size (<5 cm/≥ 5 cm), differentiation (well/poor), or cirrhosis status (≥ 20%/<20%) were also conducted, and all the above analyses supported the prognostic role of MVD in HCC.
  
  
  CONCLUSIONS
  Our meta-analysis showed that the available evidence supports the proposition that MVD has a good predictive role in HCC, especially when the patients have late stage, large size, or poorly differentiated tumors.
authors.affiliation: Center Cancer, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu - PR China.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Li
authors.forename: Xuelei
authors.initials: X
authors.lastname: Ma
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.forename: Xiaoxiao
authors.initials: X
authors.lastname: Liu
authors.forename: Lei
authors.initials: L
authors.lastname: Liu
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000098:blood supply* / Q000473:pathology; D018572:Disease-Free Survival; D006801:Humans; D015994:Incidence; D008113:Liver Neoplasms / Q000098:blood supply* / Q000473:pathology; D055806:Microvessels / Q000473:pathology; D009389:Neovascularization, Pathologic / Q000473:pathology; D011379:Prognosis