Aim: The E-cadherin-catenin complex is important for cell-cell adhesion of epithelial cells. Impairment of one or more components of this complex is associated with poor differentiation and increased invasiveness of carcinomas. We evaluated the expression pattern of E-cadherin and beta-catenin in gastric carcinoma and dysplasia and analyzed their relationship with tumor clinicopathological features and patient survival.
Methods: Immunohistochemical staining of E-cadherin and beta-catenin was performed from paraffin specimens of 163 gastric carcinomas, 44 gastric mucosal dysplasia, and 25 intestinal metaplasia, 28 atrophic gastritis and 12 healthy controls.
Results: Normal membrane staining was observed in intestinal metaplasia, atrophic gastritis and control biopsy specimens for E-cadherin and beta- catenin. 36 % and 16 % of gastric dysplasia were stained abnormally for E-cadherin and beta- catenin respectively. Abnormal expression of E-cadherin and beta- catenin was demonstrated in 46 % and 44 % of gastric carcinoma respectively. Abnormal expression of E-cadherin and beta- catenin occurred more significantly in Borrmann III/IV than in Borrmann I/II type (P<0.005, respectively). A significantly higher proportion of signet-ring,mucinous and tubular adenocarcinomas were abnormally expressed for E-cadherin and beta- catenin as compared with papillary adenocarcinomas (chi(2)=8.47,P<0.005, and chi(2)=7.05, P<0.01, respectively). Morever, abnormal E-cadherin and beta- catenin staining occurred more frequently in diffuse than in intestinal type of tumor (chi(2)=18.18 and 17.79, P<0.005, respectively). There was a significant correlation between abnormal beta- catenin expression and positive lymph node metastasis. A survival advantage was noted in tumors retaining normal membranous expression of beta-catenin, independent of type, grade, or stage of the disease (P<0.0005).
Conclusion: Abnormal expression of the E-cadherin- catenin complex occurs frequently in gatric carcinoma, closely related to its histogenesis. Abnormal expression of the E-cadherin- catenin complex in gastric dysplasia may be an early event in the tumorigenesis. The close correlation with poor survival suggests that abnormal beta-catenin may be a useful prognostic marker.