Determination of HER2 gene amplification in breast cancer using dual-color silver enhanced in situ hybridization (dc- SISH) and comparison with fluorescence ISH (FISH).

BACKGROUND The two basic methods that are currently accepted to identify the HER2 status are immunohistochemistry and flyorescence in situ hybridization (FISH) . The aim of this study was to perform the dual-color silver in situ hybridization (dc-SISH) technique as an alternative to FISH. MATERIALS AND METHODS A total of 40 invasive breast carcinoma cases were assessed for HER2 gene amplification by FISH and dual- color SISH. RESULTS Significant correlation was found in the HER2 expression results obtained with the two approaches (p=0.001, p<0.05). The concordance rate was 92.3%. CONCLUSIONS Foutine practical use of the dc-SISH method, which is much easier to apply, score, and evaluate, has many advantages. HER2 and CEN17 status can be evaluated simultaneously with the newly developed "Dual-Color Probe". All these specifications and the reliable results obtained support the widespread use of SISH technique in clinical practice.