Association of Human Epidermal Growth Factor Receptor-2 Overexpression with Subtype and Grade of Gastric Adenocarcinoma

Abstract

Background & Objective: Gastric cancer is associated with substantial morbidity and mortality worldwide. It is the
fourth most commonly diagnosed cancer and the second most common cause of cancer related deaths globally. With
increasing understanding of the molecular biology of HER2, and the availability of genomics and proteomics analysis, it
has now been recognized that HER2 is implicated in other severe forms of cancers, notably gastric cancers. The
objective of the study was to evaluate the frequency of over-expression of HER2 in patients of gastric adenocarcinoma.
Methodology: A retrospective cross sectional study was carried out in Head Office Chughtai Lab, Lahore from 1st July
2024 to 31st December 2024. Atotal of 65 diagnosed cases of gastric adenocarcinoma of both genders were included in
the study. All autolyzed/poorly fixed specimens and metastatic gastric adenocarcinomas were excluded. The
histological preparation was performed by classic method for inclusion in paraffin followed by hematoxylin and eosin
staining. The immunohistochemical analysis was performed on serial sections using immune-enzymatic soluble
complex method. The antibody used was HER2 polyclonal antibodies from DAKO. HER2 scoring was conducted as 0, +1,
+2 and +3.
Results: Age range in this study was from 30 to 70 years with mean age of 56.492±11.91 years. Male gender was
dominant (61.5%) as compare to females (38.5%). Over-expression of Her 2 was seen in 24.6% patients with gastric
adenocarcinoma. Moreover, HER2 overexpression was found to be an independent prognostic factor in well to
moderately differentiated adenocarcinomas with intestinal sub-type.
Conclusion: HER2 overexpression is a poor prognostic indicator in well to moderately differentiated, intestinal
subtype-, early stage gastric adenocarcinomas. Therefore, IHC 3+ and 2+ cases should be further analyzed by FISH to
assess HER2/neu gene status.