Differences in the angiogenesis of benign and malignant ovarian surface epithelial tumors demonstrated by microvessel density and immunohistochemistry

Abstract

Shelly Sehgal, Prashant Goyal, Reena Agarwal, Sompal Singh, Awanindra Kumar,Ruchika Gupta, Vinita Kumar, Dipti Agrawal

Objectives: Angiogenesis plays a key role in tumor growth and metastasis. The analysis of tumor vascularization by microvessel density (MVD) and its prognostic significance has been evaluated in many tumors including ovary. However, very few studies have tried to evaluate the characteristics of these vessels. This study aims to quantitatively assess the characteristics of tumor vessels with the aid of immunohistochemistry and thus, establish its role in difference in biological behavior of benign and malignant surface epithelial ovarian tumors. Methods: We examined 42 cases of ovarian surface epithelial tumors and divided them in two groups (14 malignant and 28 benign tumors). Both study groups were compared for smooth muscle and endothelial cells in tumor vessels using monoclonal antibodies against smooth muscle actin (SMA) and CD34 (endothelial cell marker). MVD, SMA expression index and CD34 intensity index was calculated in both groups. Results: The malignant tumors showed higher MVD (34.5±12.9) as compared to benign ovarian tumors (16.5±6.2) (p<0.001). Also, the blood vessels of malignant tumor showed significantly poor SMA expression and intense CD34 expression compared with vessels of benign tumors. Conclusions: The present study shows higher MVD, greater endothelial cell expression and poor muscle coat in tumor vessels of malignant ovarian surface epithelial tumors. These results indicate higher tumor angiogenesis with thinner vessels, which facilitates tumor spread.