National Journal of Laboratory Medicine (Oct 2016)
A Study of Epidermal Growth Factor Receptor 2 (HER2/neu) Expression in Endoscopic Biopsies and Gastrectomy Specimens of Gastric Adenocarcinomas
Abstract
Introduction: Gastric carcinoma (GC) is the fourth most commonly diagnosed cancer and has poor prognosis, since most of the patients present with advanced disease and the therapeutic options available are very few. The rate of HER2/neu gene amplification and protein overexpression by Fluorescent in situ Hybridization (FISH) and Immunohistochemistry (IHC) respectively range from 5%-53%. Treatment with HER2 inhibitor, trastuzumab, has been reported to increase overall survival in HER2-positive, inoperable, locally advanced and metastatic gastric carcinoma. Aim: To study the expression of HER2 in Gastric/GastroEsophageal Junction (GEJ) adenocarcinomas and to assess the relationship of HER2 expression with clinico-pathological parameters. Materials and Methods: Sixty cases of gastric/ gastro esophageal junction adenocarcinomas were evaluated for HER2/neu expression by immunohistochemistry (IHC) using anti-c-erbB-2. Thirty cases each of endoscopic gastric biopsies and gastrectomy specimens were randomly selected for evaluation. The results including various histopathological features and IHC expression of HER2 were compared. Results: Out of 30 gastrectomy cases, primary gastric cancers were 29 (96.6%) and one (3.3%) was primary GEJ adenocarcinoma. Thirteen (43.3%) were intestinal type and seventeen (56.6%) were diffuse type. HER2 overexpression (3+) was seen in three (10%) cases, one(3.33%) was equivocal (2+) and the rest were negative (score 0). HER2 positivity was associated with intestinal type adenocarcinoma (p<0.049). Three (10%) of 30 gastric biopsies were HER2/neu positive. Conclusion: Overexpression of HER2 may play a crucial role in the management of gastric adenocarcinoma, and therefore testing for HER2 by IHC has clear advantages, as it is easy, cost effective and feasible.
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