Correlation of EGFR and c-erbB-2 Gene Amplifications and Expression of COX-2 Protein in Invasive Ductal Carcinomas of the Breast

ABSTRACT

PURPOSE: Abnormalities of epidermal growth factor receptor (EGFR) and c-erbB-2 have been actively investigated in breast cancer. Cyclooxygenase-2 (COX-2) seems to be involved in critical steps of cancer onset and progression. The purpose of this study is to determine the correlation between the gene ampilfications of the EGFR and c-erbB-2 and expression of the COX-2. METHODS: Using Chromogenic in situ Hybridization (CISH) the gene amplification of the EGFR and c-erbB-2 were studies on paraffin sections of 47 invasive ductal carcinomas. The expression of COX-2 was studied immunohistochemically (IHC). RESULTS: Of the 47 invasive duct carcinomas, gene amplifications of the EGFR and c-erbB-2 by CISH were observed in 21 cases (44.7%) and 14 cases (29.8%), respectively. The gene amplification of EGFR was significantly correlated with tumor size, nodal metastasis, and stage. The gene amplification of c-erbB-2 showed a statistically significant correlation with tumor size and stage. The protein of COX-2 was expressed by IHC in 30 cases (63.8%). The expression of the COX-2 protein showed a statistically significant correlation with tumor size, nodal metastasis, and stage. The gene amplifications of the EGFR and c-erbB-2 between expression of COX-2 protein showed a statistically significant correlation. CONCLUSION: The gene amplification of the EGFR and c- erbB-2 may be correlated with expression of COX-2 protein in the breast cancer.