Enhanced expression of mucin 6 glycoprotein in cholangiocarcinoma tissue from patients in Thailand as a prognostic marker for survival

Background and Aim: Cholangiocarcinoma (CCA) is a mucin‐producing cancer that has poor prognosis. Mucin 6 (MUC6) is a mucin that is normally co‐expressed with the trefoil factor family‐2 (TFF2) trefoil peptide. Both MUC6 and TFF2 have been reported to be involved in the progression of many types of cancers. The aim of this study was to determine the expression of MUC6 and TFF2 in CCA tissues and associate these results with clinical data. Methods: MUC6 and TFF2 were detected in CCA tissues by immunohistochemistry. The correlations of MUC6 and TFF2 expressions with clinical data were analyzed. Results: We determined the significant co‐expression of both proteins in serial CCA tissues. The high expressions of MUC6 and TFF2 were demonstrated in 37% and 31% of patients, respectively. The expression levels decreased in the advanced stage of CCA when clinical metastasis was exhibited. The high expression of either protein showed a correlation with prolonged postoperative survival time, but only a high expression of MUC6 is significantly correlated with a 5‐year survival rate. A multivariate Cox regression analysis revealed that a low expression of MUC6, high expression of TFF2, age of patients >56 years, tumor size >5 cm, and poorly‐differentiated histological type were independent, poor prognostic indicators for CCA. Conclusion: MUC6 showed a good correlation with the survival of CCA patients. It may be of value to propose that MUC6 is a good prognostic marker for CCA management.