CD44 expression in patients with combined hepatocellular cholangiocarcinoma

Purpose: Combined hepatocellular cholangiocarcinoma (ChC) is a rare type of primary liver cancer, which is thought to have a poorer prognosis than hepatocellular carcinoma (HCC). Cancer stem cells are associated with tumorigenesis, tumor progression, recurrence, metastasis, and poor prognosis in several malignancies including HCC. The aim of this study was to investigate the expression pattern of cancer stem cell markers in ChC and HCC, and to evaluate whether this pattern correlated to patient prognosis. Methods: Thirteen patients who underwent curative hepatic resection for ChC and 13 patients who underwent curative hepatic resection for HCC (matched control cases) were included. Immunohistochemical staining for cancer stem cell markers (cytokeratin [CK]7, CK19, C-kit, cluster of differentiation [CD] 44, CD133, and epithelial cell adhesion molecule) was performed and clinical outcomes were analyzed retrospectively. Results: There was no significant difference in cancer stem cell marker expression between ChC and HCC. In ChC, the group that expressed CD44 showed earlier recurrence than the group that did not express CD44 (P = 0.040). Conclusion: The expression of cancer stem cell markers in ChC did not show a different pattern compared to that found in HCC. The expression of cancer stem cell marker CD44 was associated with poor prognosis in patients with ChC.