Clinicopathological Study of HER2/neu expression in Gastric Cancer
Author(s): Mellonie P* and Anto J Richie
Abstract
Introduction: Gastric cancer the fourth leading cause of cancer-related death. Overexpression of HER2 is seen in a significant number of gastric cancer cases leading to the development of targeted therapy with anti-HER2 antibodies like Transtuzumab. However, uncertainty persists regarding the association between the clinicopathological features of gastric cancer patients and HER2 overexpression. Aim: This study aims to find the association between clinicopathological features of gastric adenocarcinoma and HER2 overexpression. Materials and Methods: This descriptive observational study was conducted in the Department of Pathology of a tertiary care hospital laboratory in Mangalore from January 2018 to April 2021. In this study we analysed 75 consecutive specimens of gastric/gastroesophageal junction tumours. Histological types other than gastric adenocarcinoma were excluded from the study. Diagnosis was confirmed using hematoxylin and eosin (H&E) slides. IHC was done using mouse monoclonal antibody HER2 from Biogenex. Scoring for HER2 was done by Hoffmann scoring system. Tumours were classified according to Lauren’s histological classification into Intestinal and diffuse type .Other relevant details like patient’s age, gender, type of specimen, tumour location, histological type and tumour grade were collected and tabulated. Results: Out of the 75 cases of adenocarcinomas analysed in this study 48 were biopsy specimens and 27 were gastrectomy specimens. In our study the rate of overall Her2 overexpression was 25.3%. Also, Her2 overexpression was associated with Intestinal type (26.9%), GEJ Tumours, moderately differentiated carcinomas and male gender .There was no correlation of HER 2 positivity with age. (30.6%, p = 0.006). Conclusion: Since, status of HER2 expression by IHC plays pivotal role in the treatment of gastric cancer, testing for the same has increased in the recent times. Hence knowing the association of HER2 expression with clinicopathological features has a clear advantage.