INCREASED MICROVESSEL DENSITY IN MUCINOUS COMPARED WITH MALIGNANT SEROUS AND BENIGN-TUMORS OF THE OVARY

Microvessel density of benign, borderline and malignant ovarian tumour s was studied immunohistochemically using antibodies to the endothelia l cell markers CD31, CD34 and factor VIII-related antigen. Microvessel density was compared in tumours of different histological subtype, st age and patient outcome. CD31-immunostained sections were examined and regions of high and average microvessel density were selected, Identi cal regions were located on CD34- and factor VIII-related antigen-immu nostained serial sections and microvessel counts obtained and converte d to vessels mm(-2). CD31 and CD34 immunostaining revealed increased m icrovessel density in both the high and average vessel density regions of mucinous (222.4 +/- 24.8; 79.9 +/- 8.5) compared with serous (105. 4 +/- 20.7; 33.3 +/- 6.8) and benign (84.4 +/- 19.4; 20.4 +/- 4.4) tum ours (P < 0.001). CD31 and CD34 immunostaining also revealed increased microvessel density in early-stage mucinous tumours (234.6 +/- 28.2; 87.8 +/- 9.2) compared with that observed in both early- (72.8 +/- 15; 12.9 +/- 2.4) and late- (115.6 +/- 26.5; 29.8 +/- 8.5) stage serous t umours (P < 0.001). No differences in microvessel density in samples f rom patients with differing outcomes were observed (P > 0.05). Reduced factor VIII-related antigen compared with CD31 and CD34 immunostainin g was observed in both borderline and malignant mucinous and serous tu mours (P < 0.02) but not in benign tumours (P > 0.05). Our results con tradict the putative association between increased microvessel density and poor prognosis and suggest that the level and control of angiogen esis may differ between ovarian tumour types.