Immunohistochemical Comparison of Malignancy Between Radial Invasion and Mucosal Extension in Hilar Cholangiocarcinoma

To compare the cells of mucosal extension (ME) and radial invasion (RI) in hilar cholangiocarcinoma (HCCA) for optimal resection. Forty-six patients underwent surgery for HCCA between 1992 and 2004. Immunohistochemical expressions of p53, Ki-67, matrix metalloproteinase-7 (MMP7), mucin 1 (MUC1), and E-cadherin were assessed at five different sites of the tumour and compared between the recurrence and non-recurrence groups. Expression of E-cadherin was significantly lower in RI cells than in ME cells, and that of MMP7 and MUC1 was significantly higher in RI cells than in ME cells. Ki-67 expression was higher in ME cells than in RI cells. During the 11-year follow-up, recurrence in patients with R0 resection was associated with significantly lower E-cadherin, higher MMP7, and higher Ki-67 expression. Removal of as many RI cells as possible should be a priority in resection of HCCA, followed by removal of ME cells. E-Cadherin appears to be associated with recurrence of HCCA.