COX-2 status in relation to tumor microvessel density and VEGF expression: Analysis in ovarian carcinoma patients with low versus high survival rates

Cyclooxygenase-2 (COX-2), vascular endothelial growth factor (VEGF), and microvessel density (MVD) have been reported to be significantly related to carcinogenesis and to tumoral progression. The aim of the study was to analyse immunohistochemically the overexpression of COX-2 and VEGF, and the MVD between one another, and also in relation with clinical outcome in ovarian carcinoma. We selected 52 patients with ovarian carcinoma homogeneous by stage, type and histological grade, surgical and chemotherapeutic treatment. Of these, 28 patients had died of progression of their disease within 2 years of their primary surgical treatment, while 24 patients were alive with no evident disease at 5 years from the primary surgical treatment. The differences of the COX-2 status, the MVD and the VEGF expression in the two groups of ovarian carcinoma patients with low and high survival rate, respectively, were calculated according to the Fisher's exact test and the logistic regression. The shift in location of MVD in the two groups of patients was calculated according to the Wilcoxon Mann-Whitney test. MVD was correlated with COX-2 and VEGF overexpression (P=0.009 and P=0.003, respectively), COX-2 and VEGF were correlated to one another (P=0.044). In logistic regression analysis, COX-2, VEGF, and MVD were significant (P=0.017, P=0.008, P<0.0005, respectively). In the cases with low survival rate, the average MVD was 102, while in the cases with high survival rate the average MVD was 40.5 (P<0.0005). The evaluation of the COX-2, the VEGF and the MVD may give additional prognostic information for first-line chemotherapy and clinical outcome of patients with ovarian carcinoma and may encourage selection of more tailored therapies. Angiogenesis inhibitors or COX-inhibitors probably can have synergistic effects with chemotherapy.