HER2-Neu Gene Testing in Gastric Cancer by Immunohistochemistry in Tunisian Patient’ Samples

Abstract

Immunohistochemical (IHC) testing for HER2/neu is becoming the standard of care for guiding the adjuvant treatment of gastric carcinoma with trastuzumab. Up to now, gastric cancer has been considered the most commonly diagnosed tumors leading to death.In this study, we evaluate the detection of HER2 expression by IHC in Tunisian patients with gastric cancer according to the international consensus. A total of 84 tumor specimens was assessed for HER2 expression by immunohistochemistry (IHC) using the antibodies HercepTest™. Doubtful IHC results (IHC 2+) were resolved by HER2 Chromogenic in situ hybridization (CISH). Thus, 10.5% of samples were HER2-positive (3+), 8.3% having a negative score IHC, Her2-Neu (+1) and 3.6% to be a dubious immunostaining Her2-Neu (2+).