E-cadherin Immunoexpression Patterns in Gastric Carcinoma Histological Subtypes: A Hospital-based Descriptive Study

Introduction: Gastric carcinoma is the second common Gastrointestinal (GIT) malignancy. Based on Global Cancer Observatory (GLOBOCAN) 2020 data, it is the 5th most common neoplasm and the 4th most common cause of death. Epithelial-cadherin (E-cadherin) is a transmembrane glycoprotein which plays a crucial role in maintaining cell-cell adhesion. Loss of E-cadherin contributes to enhanced invasion and metastasis in human cancers.

Aim: To study E-cadherin immunohistochemical expression in tumour cells and its association with gastric carcinoma histotypes.

Materials and Methods: It is a hospital-based descriptive study conducted at Department of Pathology, Osmania General Hospital, Hyderabad, Telangana, India from January 2010 to December 2012 as it was my dissertation. Routine histopathology and immunohistochemistry for E-cadherin were done on the sections. E-cadherin immunohistochemical staining and expression in tumour cells were evaluated according to the study by Jawhari A et al., Scores (0-3) were applied: 0-No staining; 1-Only cytoplasmic staining; 2-Cytoplasmic and membranous staining in the same case, 3-Normal membranous immunoexpression. Staining was evaluated based on absence of membranous expression scores (0 and 1) versus the presence of membranous expression (scores 2 and 3). Statistical analysis of the data was done by Chi-square test using Epi Info software.

Results: Total 70 cases were studied, of which 48 were gastric biopsies and 22 were gastrectomies. Gastric adenocarcinomas were classified as intestinal 40 cases (57.14%) and diffuse 30 cases (42.85%) according to Lauren’s classification. Membranous staining of E-cadherin was seen in 34/40 cases (85%) of intestinal gastric cancer and 9/30 cases (30%) of diffuse intestinal cancer whereas non membranous or absent E-cadherin was seen in 6/40 cases (15%) of intestinal gastric cancer and 21/30 cases (70%) of diffuse gastric cancer. In this study, significant association was found between membranous E-cadherin expression (score 2 or 3) and intestinal histotype and absence of membranous expression (scores 0 or 1) and the diffuse histotype of gastric cancer.

Conclusion: Normal gastric mucosa shows strong membranous E-cadherin positivity. There is a change in the pattern of E-cadherin expression from membranous in intestinal type gastric adenocarcinoma to non membranous expression of E-cadherin in diffuse type of gastric carcinoma.