Relationship between β-catenin expression and prognostic parameters of colorectal carcinomas

Colorectal carcinomas are the most frequent tumors of the gastrointestinal tract. β-catenin, which is related to cadherins, is a cytoplasmic protein responsible for intercellular adhesion. It is also an important component in the Wnt signal pathway. Recent studies have shown structural alterations in the APC gene and axin in patients with colorectal carcinoma, along with β-catenin. We aimed to compare β-catenin expression, which is a prognostic factor itself, with other prognostic parameters.

A total of 70 patients who had surgical intervention for colorectal malignancies between January 1994 and December 2003 were included in the study. Fift y-nine of the patients (84.3%) were male, 11 of the patients (15.7%) were female; their ages varied between 24 and 82 (mean 60.3 ±15.2) years. Paraff in blocks were immunohistochemically stained for β-catenin. The number of stained cell nuclei was assessed according to the stage of disease using the TNM classification, histological grade, lymphatic invasion, vascular invasion and tumor's local invasion.

When groups constituted according to tumor histologic grade were compared for prognostic parameters in terms of stain density for β-catenin and number of stained cell nuclei, stain density was mild (+) and the number of stained nuclei was smaller in well-differentiated groups while stain density was strong (+++) and the number of stained nuclei was higher in poorly differentiated groups. There was a relation between β-catenin expression and differentiation grade, lymph node metastasis, stage and tumor size but not with vascular invasion.

These data indicate that β- catenin, with functions in cell homeostasis and relations with the APC gene, has a substantial role in colorectal carcinogenesis.