Expression of E-cadherin and beta-catenin in the adenoma-carcinoma sequence of ampulla of Vater cancer.

Objective: Ampullary carcinoma is uncommon but provides a good model for adenoma-carcinoma sequence. During the adenoma-carcinoma transition, the tumor cells should acquire the ability to invade. The E-cadherin-catenin complex connects the adjacent epithelial cells at the zona adherens, and this adhesion interferes with the tumor cell invasion.

Methods: 111 cases of ampullary carcinoma were investigated with E-cadherin and beta-catenin expression with immunohistochemistry and the result was compared with their clinicopathologic and survival results. Forty-nine (44.1%) cases were associated with adenomatous component.

Results: Expressional loss of E-cadherin was detected in 3 (6.1%) adenomas and 73 (65.8%) carcinomas, and the expressional loss was significantly associated with tumor cell differentiation (p<0.05) and survival (p<0.05) in carcinoma. In beta-catenin immunostaining, 4 (8.2%) adenomas and 45 (40.5%) carcinomas showed abnormal staining patterns either as nuclear staining or as a loss of membrane staining. The cases with membranous loss of beta-catenin expression were correlated with poor survival rate.

Conclusions: Alteration of E-cadherin and beta-catenin is a late event during the adenoma-carcinoma sequence in ampullary neoplasms, and the loss of membranous expression of both E-cadherin and beta-catenin is closely correlated with less differentiated histology and poor prognosis.