Pandey, IMisra, VPandey, ATVerma, A.2023-08-102023-08-102022-03Pandey I, Misra V, Pandey AT, Verma A.. Expression of HER2/neu in gastric adenocarcinoma and its correlation with serum HER2/neu level and E-cadherin expression. Indian Journal of Pathology & Microbiology. 2022 Mar; 65(1): 35-410377-49290974-5130http://imsear.searo.who.int/handle/123456789/223236Aim: To assess HER2/neu expressions and correlate with E-cadherin and Serum HER2 level in gastric carcinoma. Method: 31 gastric biopsies and 1 resected specimen were taken in the study with patient details and stained with H and E for histopathological details following Lauren's classification. Immunohistochemistry for HER2 and E-cadherin expression was conducted followed by serum HER2/neu ELISA. Result: Adenocarcinoma with 61% diffuse, 29% intestinal, and 10% other type were observed with predominant HER2 immunoexpression in intestinal-type than in diffuse-type adenocarcinoma. Other observations marked 44% as 3+/positive and 56% as 2+/equivocal in intestinal type while 26% cases as 3+/positive, 69% as 2+/equivocal, and 1% as 1+/negative were observed in diffuse type. The data presented 33% membranous positivity and 67% both membranous + cytoplasmic positivity in intestinal type while 2% showed membranous positivity, 47% both membranous + cytoplasmic, and 42% only cytoplasmic positivity in diffused type. On comparing the localization pattern of HER2 and E-cadherin, 25% of cases showed membranous staining while 50% of cases showed membranous with cytoplasmic staining for both. No cytoplasmic HER2 staining as well as no any staining for E-cadherin was shown by 6% cases. Conclusion: Thus, it can be concluded that cytoplasmic expression of HER2 in gastric adenocarcinoma (mainly diffuse type) may be due to shedding of its extracellular domain, leading to loss of membranous E-cadherin expression on immunohistochemistry. The loss of membranous expression of E-cadherin and increased serum HER2 ELISA were correlated well with these findings.E-cadheringastric adenocarcinomaHER2/neuimmunohistochemistryserum ELISAJournal ArticleIndiaDepartment of Pathology, MotiLal Nehru Medical College, Prayagraj, Uttar Pradesh, IndiaCentre of Biotechnology, University of Allahabad, Prayagraj, Uttar Pradesh, IndiaBioorganic and Medicinal Chemistry Research Laboratory, Department of Pharmaceutical Sciences, SHUATS, Prayagraj, Uttar Pradesh, India