Diagnostic value of IHC and FISH methods for HER2 gene amplification detection in paraffin embedded blocks of breast cancer

Introduction: Breast cancer is the leading cause of malignancy related deaths in women worldwide. In 20%-30% of breast cancers, HER2 gene amplification or overexpression is observed. Determination of HER2 amplification is performed mainly by IHC technique to measure its protein expression on the cell surface and by FISH to check gene amplification. This study was aimed to compare the sensitivity and specificity of IHC in comparison to the FISH method for detection of HER2 gene amplification. Methods: In this study which was performed in 2020, 44 paraffin embedded breast carcinoma tissues belonging to women with breast cancer which have been already examined with IHC technique have been analyzed using FISH technique to determine HER2+ overexpression. Data were analyzed using GraphPad (Anova ver8) software. P