Prevalence of HER2 Expression and Its Correlation with Clinicopathological Parameters in Gastric or Gastroesophageal Junction Adenocarcinoma in North-East Indian Population

Document Type: Research Articles

Authors

1 Department of Medical Oncology, Dr B Borooah Cancer Institute, Guwahati, Assam, India.

2 Department of Surgical Oncology, Dr B Borooah Cancer Institute, Guwahati, Assam, India.

3 Department of Pathology, Dr B Borooah Cancer Institute, Guwahati, Assam, India.

Abstract

Objective: Human epidermal growth factor receptor 2 (erbb2/HER2) overexpression, has now been implicated
in advanced gastric and gastroesophageal junction cancers. The study was conducted to determine the rate of HER2
positivity in patients with locally advanced or metastatic gastric and gastroesophageal adenocarcinoma in North-East
India and to assess the impact of various demographic and clinical parameters on HER2 positivity. Methods: A total of
68 patients of age >18 years of gastric and gastroesophageal adenocarcinoma diagnosed on histopathological examination
from September 2016 to February 2018 at Dr B Borooah Cancer Institute, Assam were enrolled for the observational
(epidemiological) study. All patients were subjected to the HER2 immunohistochemistry test using a FDA-approved,
standardized test kit. HER2 expression was correlated with various demographic and clinicopathological parameters.
Results: The overall rate of HER2 positivity in the population studied was 56% (n=38). The rate was non-significantly
higher in male, older age group (>60 years) and Hindu population. Similarly, HER2 positivity rate was higher in patients
with well differentiated histology and was more common in patients with stage II and III diseases, but neither of the
associations is statistically significant. HER2 positivity rate was significantly higher in proximal and in GEJ tumours
(56% versus 44%, P=0.002). Conclusion: HER2 overexpression was evident in 56% of the North-East Indian patients
with locally advanced and metastatic gastric and gastroesophageal adenocarcinoma. The overexpression correlated
significantly with primary tumour site. Routine testing of gastric and gastroesophageal tumours for HER2 expression
is recommended to provide a therapeutic advantage in Indian patients.

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