Association of Human Epidermal Growth Factor Receptor-2 (HER2) Over Expression with Subtype and Grade of Gastric Adenocarcinoma

Background & Objective: Gastric cancer is associated with substantial morbidity and mortality worldwide. It is thefourth most commonly diagnosed cancer and the second most common cause of cancer related deaths globally. Withincreasing understanding of the molecular biology of HER2, and the availability of genomics and proteomics analysis, ithas now been recognized that HER2 is implicated in other severe forms of cancers, notably gastric cancers. Theobjective 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 July2024 to 31st December 2024. Atotal of 65 diagnosed cases of gastric adenocarcinoma of both genders were included inthe study. All autolyzed/poorly fixed specimens and metastatic gastric adenocarcinomas were excluded. Thehistological preparation was performed by classic method for inclusion in paraffin followed by hematoxylin and eosinstaining. The immunohistochemical analysis was performed on serial sections using immune-enzymatic solublecomplex 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 wasdominant (61.5%) as compare to females (38.5%). Over-expression of Her 2 was seen in 24.6% patients with gastricadenocarcinoma. Moreover, HER2 overexpression was found to be an independent prognostic factor in well tomoderately differentiated adenocarcinomas with intestinal sub-type.Conclusion: HER2 overexpression is a poor prognostic indicator in well to moderately differentiated, intestinalsubtype-, early stage gastric adenocarcinomas. Therefore, IHC 3+ and 2+ cases should be further analyzed by FISH toassess HER2/neu gene status.