# Human Epidermal Growth Factor 2 (Her-2) Expression in Gastric and Gastroesophageal Carcinomas: A Clinicopathological Evaluation in a Tertiary Care Institute

## TL;DR

This study examines HER-2 expression in gastric and gastroesophageal carcinomas and finds it is more common in certain age groups and tumor types, which could help guide targeted therapies.

## Contribution

The study identifies specific age groups and histological types with higher HER-2 positivity, offering insights for targeted therapy selection.

## Key findings

- HER-2 positivity was significantly higher in 20-39 years and ≥80 years age groups.
- Moderate and poorly differentiated carcinomas showed higher HER-2 positivity.
- Tubular and papillary adenocarcinoma types were significantly associated with HER-2 positivity.

## Abstract

Introduction

Gastric carcinoma is a significant global health concern, known for its high mortality rate. HER-2 overexpression is observed in a notable proportion of gastric carcinoma and is associated with a worse prognosis. However, HER-2 expression enables targeting the protein by monoclonal antibodies that improve overall survival in HER-2-positive gastric cancers. This study aims to evaluate the HER-2 expression in gastric and gastroesophageal carcinomas.

Materials and methods

This observational study was conducted in the Department of Pathology, involving 60 endoscopic biopsy and resection specimens of gastric and gastroesophageal carcinomas. HER-2 expression was assessed by immunohistochemistry (IHC) based on the Trastuzumab for GAstric Cancer (ToGA) trial’s scoring system. The primary outcome was HER-2 status, with statistical analysis performed to evaluate associations with various clinicopathological parameters.

Results

Among 60 cases, 26 (43.3%) showed HER-2 positivity. HER-2 positivity was significantly (p=0.004) associated with age, being higher in 20-39 years and ≥80 years age groups. Gender and tumor location were not significantly associated with HER-2 positivity. Moderate and poorly differentiated carcinomas exhibited higher HER-2 positivity. Histological types, tubular adenocarcinoma, and papillary adenocarcinoma showed significant (p=0.01) association with HER-2 positivity compared to other types.

Conclusion

HER-2 status assessment is crucial in managing gastric and gastroesophageal carcinomas. HER-2 positivity is notably higher in certain age groups and histological types particularly tubular and papillary adenocarcinoma, and in moderately to poorly differentiated carcinomas. These insights can aid in selecting appropriate gastric and gastroesophageal carcinomas that warrant HER-2 testing on IHC. Identifying gastric and gastroesophageal carcinomas that show HER2 expression may highlight potential candidates for targeted therapy.