Abstract

Aim: Stomach cancer is the fourth most common cancer worldwide. It is a significant cause for morbidity and mortality globally.HER2(Human Epidermal Growth Factor 2) status in gastric carcinoma has been studied worldwide, however there is sparse published data from Bahrain. Hence, this study was taken up to evaluate HER2 overexpression in gastric adenocarcinoma patients and to assess the relationship between its expression and clinicopathological tumor parameters.

Study design and settings: Retrospective study was conducted in Salmaniya Medical Complex-The main tertiary care center in Bahrain, over a 5 years period.

Study material: All the partial and complete gastric resection specimens and biopsies received in that period. HER-2 Immunohistochemistry (IHC) was done on most of the cases and the reports were reviewed for its expression in formalin-fixed paraffin-embedded tissue samples. Fluorescence In Situ Hybridization (FISH) was done for equivocal cases on IHC.

Data analysis: The data was analyzed using Microsoft Excel 2013.

Results: HER2 overexpression was confirmed in 4 (7.4%) cases of which 3 (75%) cases were of intestinal type whereas only 1 (25%) case of diffuse type adenocarcinoma.

Conclusion: HER2 positivity was more common in the intestinal type of gastric cancer compared to the diffuse type. Positivity of HER2 was found more in small biopsies as compared to the resection specimens in this study. HER2 overexpression was more in females, age more than 55 years old and in moderately and poorly differentiated adenocarcinoma. HER2 overexpression was not analyzed with the cancer stage because of data limitations.

Keywords: Stomach cancer; Immunohistochemistry; Trastuzumab; Adenocarcinoma