COX-2 Expression Does Not Correlate with Microvessel Density in Breast Cancer

Abstract

Background:Cyclooxygenase-2 (COX-2), implicated in carcinogenesis and tumour progression in many cancers including breast cancer, is hypothesised to cause progression by promoting angiogenesis. The exact mechanism of such action is not known and the clinical evidence of such interaction is weak. We studied COX-2 expression and microvessel density (MVD) in malignant breast tissues. Methods:COX-2 expression was analysed by immunohistochemistry in 89 breast cancer cases. MVD was assessed by CD31 immunohistochemistry using the Chalkey count method. COX-2 expression and MVD data were correlated with each other and with other prognostic factors. Results: COX-2 expression, observed in 70 (79%) cases, correlated positively with tumour type (p = 0.037) and tumour grade (p = 0.045), but negatively with oestrogen receptor (p = 0.013). It did not correlate with tumour size, axillary lymph node status, progesterone receptor and HER-2 status. MVD varied from 2.09 to 40.38, correlated positively with tumour grade (p = 0.050) and tumour size (p = 0.044), but negatively with progesterone receptor (p = 0.040). MVD did not correlate with tumour type, axillary lymph node status, oestrogen receptor and HER-2. There was no correlation between COX-2 expression and MVD (p = 0.702). Conclusions: COX-2 expression does not correlate with angiogenesis in breast cancer. Angiogenesis in breast cancer may be dependent on multiple genes, rather than on COX-2 alone.