Reduced expression of components of the cell-cell adhesive cadherin-catenin complex has been related to the invasive phenotype in many malignancies, but the prognostic value of altered expression of its separate components varies in colon cancer. Our objective was evaluation of the cadherin-catenin complex, considered as a functional unit, in colon carcinomas and its relationship to patient outcome.
Tumours from 206 patients operated for colon adenocarcinoma were analysed using immunohistochemistry of E-cadherin, alpha, beta, and gamma-catenins, and p120ctn. The sum of proteins with altered membranous expression was calculated as an overall adhesion score (ranging from 0 to 5) for each patient. The results were correlated with patient outcome.
Of the tumours included in the analysis 0.5% had score 0, 4.9% had score 1, 13.6% had score 2, 31.6% had score 3, 33.0% had score 4, and 16.5% tumours had score 5. None of the proteins examined had individual, independent prognostic value. However, an increase in the number of proteins in the cadherin-catenin complex with altered expression was associated with an increased risk of cancer death (univariate P=0.002; multivariate P=0.007, HR 1.48, 95% CI 1.11-1.96).
An increase in the number of adhesion proteins with altered expression in the primary tumour is associated with increasingly impaired prognosis for patients operated for colon carcinoma. The results reveal that the entire cadherin-catenin complex should be evaluated when assessing its prognostic value in the disease.