Abstract

PROGNOSTIC SIGNIFICANCE OF MEMBRANE ASSOCIATED HUMAN EPIDERMAL GROWTH FACTOR RECEPTOR 2 IN GASTRIC ADENOCARCINOMAS

Nisha Raj PhD, Divya Verma PhD, Ashok Kumar MCh, Praveer Rai DM, Ram Nawal Rao MD*

ABSTRACT

Background: The difficulty in detecting gastric cancer at an early
stage and the lack of effective therapy all contribute to the high
mortality. Human epidermal growth factor receptor2 (HER2) one of
the first molecular targeted drugs developed, is a transmembrane
glycoprotein, involved in the signal transduction pathways leading to
cell growth and differentiation. Clinical demand for HER2 testing is
rapidly increasing after the recent introduction of trastuzumab (anti-
HER2 antibody) for the treatment of patients with breast cancers. The
objective of this study was to evaluate the prognostic significance of
HER2 overexpression in gastric adenocarcinomas patients. Methods:
We included 63 prospective patients with gastric adenocarcinomas
diagnosed at Sanjay Gandhi Postgraduate Institute of Medical Sciences
between 2015-2017. Expression of HER2 oncoprotein was evaluated
by immunohistochemistry using HER2 antibody. HER2 expression was further correlated
with clinicopathological parameters. Results: Out of 63 cases of gastric adenocarcinoma,
there were 48(76.2%) males and 15(23.8%) females with a mean age of 53.9 yrs. Moderately
differentiated adenocarcinoma was predominant 27(42.8%) followed by poorly differentiated
24(38%) and well differentiated type 12(19%). HER2 positivity was observed in 40% of cases. The HER2 expression was evaluated as staining score of 0 in 15(24%) patients 1+ in 23(36.5%), 2+ in 16 (25.3%), and 3+ in 9(14.3%) patients. HER2 positivity was not significantly associated with gender, tumor site (antropyloric), histological subtypes, tumor differentiation and depth of infiltration (p>0.05). Conclusion: Standardized scoring criteria and accurate assessment of HER2 expression in gastric adenocarcinoma is of importance and may be helpful in the optimal selection of patients for trastuzumab (Herceptin) therapy.

Keywords: Gastric adenocarcinomas, HER2/NEU (Human Epidermal Growth Factor Receptor2), Immunohistochemistry (IHC), Haematoxylin and Eosin (H&E).