Fluorescent in Situ Hybridization Her2/Neu Gene Amplification and Detection in Breast Cancer Patients
Muhammad Imran Sarwer, Saleha Zafar, Arif Malik , Muhammad Shahbaz Hussain , Faraz Chudary Sherif, Muhammad Kashif Munir
Abstract
Background: Fluorescence in situ hybridization (FISH) is the most predictive and accurate test for diagnosing HER 2/neu gene amplification and is also used to observe the therapeutic outcome of breast cancer
Objective: To evaluate the amplification and detection of the HER2/neu gene in breast cancer patients using Fluorescence In Situ Hybridization (FISH) and to compare the results with Immunohistochemical (IHC) analysis.
Methodology: This Research was undertaken to investigate HER-2/ neu gene amplification and detection by FISH in different types of breast cancer and age groups compared to immunohistochemical (IHC) stain analysis that uses tissue specimens embedded in paraffin. IHC and FISH analyzed a total of 70 tissue specimens from breast cancer patients. Mouse monoclonal antibodies were used for IHC corresponding to the intracellular domain of HER-2/neu protein (IHC HER 2/neu= 2+) while amplified products of the same samples were detected by using FISH.
Results: Breast cancer was tested for HER2/Neu and results were graded as positive or negative. “Positive result” was an amplification ratio of >2.25 and for “negative result” was a ratio of <1.8. 34% FISH her 2/neu gene was amplified and detected in Grade III Invasive Ductal Carcinoma and 30% in Grade II Invasive ductal Carcinoma and 100% gene was amplified in residual Invasive ductal carcinoma and metaplastic Carcinoma Grade III. 0% gene was amplified in Invasive Lobular Carcinoma Grade II, Papillary Neoplasm, and Invasive Papillary Carcinoma Grade II.
Keywords: Fluorescent in situ hybridization, Immunohistochemistry, Her2/neu, Breast cancer