Microvessel density as a prognostic factor in ovarian cancer: a systematic review and meta-analysis

The prognostic value of microvessel density (MVD), reflecting angiogenesis, detected in ovarian cancer is currently controversial. Here we performed a meta-analysis of all relevant eligible studies.

A comprehensive search of online PubMed, Medline, EMBASE and Sciencedirect was performed to identify all related articles. The search strategy was designed as 'microvessel density', 'ovarian cancer', 'ovarian neoplasm', 'CD34' and 'angiogenesis'.

The studies were categorized by author/year, number of patients, FIGO stage, histology, cutoff value for microvessel density, types of survival analysis, methods of hazard rations (HR) estimation, HR and its 95% confidence interval (CI). Combined hazard ratios suggested that high MVD was associated with poor overall survival (OS) and progression-free survival (PFS), with HR and 95% CIs of 1.84 (1.33-2.35) and 1.36 (1.06-1.66), respectively. Subgroup analysis showed that high MVD detected by CD34 was relevant for OS [HR=1.67 (1.36-2.35)], but not MVD detected with other antibodies [HR=2.11 (0.90-3.31)]. Another subgroup analysis indicated that high MVD in patients without pre-chemotherapy, but not with pre- chemotherapy, was associated with OS [HR=1.88(1.59-2.18 and HR=1.70 (-0.18-3.59)].

The OS and PFS with high MVD were significant poorer than with low MVD in ovarian cancer patients. However, high MVD detected by CD34 seems to be more associated with survival for patients without pre-chemotherapy.