Expression of Smad7 in Cholangiocarcinoma: Prognostic Significance and Implications for Tumor Metastasis

Background: There are few molecular markers known to predict cholangiocarcinoma (CCA) prognosis.Smad7 has a certain relationship with epithelial-mesenchymal transition (EMT), but its relevance to CCA inunclear. Therefore expression and clinical significance of Smad7 in CCA was the focus of this study.
Methods:Expression of Smad7, E-cadherin and vimentin was assessed in 41 patients with CCA by immunohistochemistryand analyzed for associations with clinical parameters.
Results: Smad7 and vimentin expression in the CCA tissuewas dramatically higher than that in adjacent tissues. In addition, Smad7, vimentin and E-cadherin expressionwas significantly associated with CCA lymph node metastasis and perineural invasion(P≤0.05), but not otherfactors, such as gender, age, tumor location, tumor type and tumor differentiation degree (P>0.05). The overallsurvival and relapse-free survival rate was significantly higher in patients with negative Smad7 expression thanthose with positive Smad7 expression.
Conclusion: EMT phenomena may occur in the process of CCA invasionand metastasis. Smad7, which was highly expressed in CCA, may be considered to be one feedback regulatorin late stages and could have potential as a prognostic indicator for clinical assessment.