Her-2/neu gene amplification compared with HER-2/neu protein overexpression on ultrasound guided core-needle biopsy specimens of breast carcinoma.

Genomic amplification and oncoprotein overexpression of Her-2/neu was studied on ultrasound core needle biopsy specimens of the infiltrative ductal carcinomas of the breast. We performed two colour fluorescence in situ hybridization (FISH) for Her-2/neu and chromosome 17 and compared the FISH results with the immunohistochemical overexpression of Her-2/neu protein by 2 antibodies (DAKO HercepTest and the BioGenex monoclonal antibody AM 134-5M). Furthermore, following radical mastectomy with axillary dissection, Her-2/neu status of the patients were compared with the well known histopathological prognostic factors such as histologic grade, tumor stage, lympho/ vascular invasion, surgical margin status and Paget s disease. Amplification was demonstrated 27% of the cases. Her-2/neu protein overexpression was detected in 47% and 80% of the cases with CB11 and HercepTest respectively. We revealed statistically significant association between the tumor, oncoprotein expression and oncogene amplification (p<0.05). The results of our study showed that combination of IHC and FISH methods enhances the evaluation of tumor genetics at both gene and protein level for the analysis of Her-2/neu in breast carcinoma.