Objective: we are aiming to study the expression of human epidermal growth factor 2 (HER2) in
gastric carcinoma (GC) to estimate the susceptibility for target therapy by trastuzumab hoping to
improve the outcome especially in late stage cases.
Methods: This is a retrospective study that included 50 cases diagnosed as GC in Benha
university hospital. Our study included an examination of the endoscopic biopsies of 40 cases
and the resection specimens of 10 cases. We assessed HER2 status by application of
Immunohistochemistry (IHC) to all the cases. When equivocal cases on IHC, we applied
Fluorescence In Situ Hybridization (FISH). The collected data were statistically analyzed.
Results: HER2 was positive in 17 (34%) cases. It was statistically significant (p < 0.05) in the
intestinal type of gastric cancer than in the diffuse type (94.1% and 5.9 %, respectively). We
found the HER2 positivity more in small biopsies than in the resected specimens, but it was
statistically nonsignificant. Our data showed no difference in HER2 positivity in relation to the
tumor site, differentiation, and tumor stage.
Conclusions: HER2 is overexpressed in the intestinal subtype of GC. So, this subtype of GC can
be treated by target immunotherapy ―trastuzumab‖.