HER-2 DNA quantification of paraffin-embedded breast carcinomas with LightCycler real-time PCR in comparison to immunohistochemistry and chromogenic in situ hybridization

3627 Introduction: Accurate determination of HER-2 gene amplification status is a prerequisite for establishing prognosis and selecting specific treatment for breast cancer patients. The aim of the current study was to compare the detection of HER-2 status by real-time PCR, on paraffin-embedded breast carcinomas, in respect to immunohistochemistry (IHC) and chromogenic in situ hybridization (CISH). Methods: Paraffin-embedded breast carcinomas collected from 85 patients diagnosed with early stage breast cancer were analyzed for HER-2 gene amplification by real-time PCR and CISH, as well as for HER-2 protein expression by IHC. Results: HER-2 gene amplification was observed in 19 (22.4%) of 85 breast cancer patients by real-time PCR and in 19 (22.4%) of 85 patients by CISH. Strong (3+) HER-2 protein overexpression was observed in 13 (15.3%) of 85 patients. Moreover, there were 4/85 (4.7%) patients that had moderate (2+) HER-2 protein overexpression, while 68/85 (80%) patients had no HER-2 protein overexpression by IHC. There were strong concordance rates between real-time PCR and IHC (79/85, 92.9%, p