Expression of Cyclooxygenase-2 in Human Breast Carcinoma: Relevance to Tumor Angiogenesis and Expression of Estrogen Receptor

Abstract

Purpose: This study investigates the COX-2 expression in human primary breast carcinomas and its relationship with both angiogenesis and the expression of estrogen receptor.

Materials and methods: COX-2 expression, angiogenesis, and estrogen receptor expression were examined by immunohistochemical methods in 167 human breast carcinomas by using monoclonal antibodies against COX-2, CD34, and estrogen receptor protein.

Results: Although COX-2 was expressed in 77.8% of the breast carcinomas (130/167) regardless of histological types, it was not detected at all in benign epithelial cells. Interestingly, COX-2 expression was found to be significantly correlated with tumor angiogenesis (p=0.004), but not with estrogen receptor and other histopathologic parameters.

Conclusion: The results suggest that COX-2 expression occurs frequently in breast tissue during transformation of benign epithelial cells to malignant cells regardless of the estrogen receptor status. COX-2 expression may play a role in tumor angiogenesis that is responsible for tumor growth and metastasis.

Keywords: Angiogenesis; Breast neoplasm; Cyclooxygenase-2; Estrogen receptor.