title: CD44 expression in patients with combined hepatocellular cholangiocarcinoma.
abstract: OBJECTIVE
  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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Surgery, Korea Cancer Center Hospital, Korea Institute of Radiological & Medical Sciences, Seoul, Korea.
authors.forename: Ryounggo
authors.initials: R
authors.lastname: Kim
authors.affiliation: Department of Surgery, Korea Cancer Center Hospital, Korea Institute of Radiological & Medical Sciences, Seoul, Korea.
authors.forename: Sang Bum
authors.initials: SB
authors.lastname: Kim
authors.affiliation: Department of Surgery, Korea Cancer Center Hospital, Korea Institute of Radiological & Medical Sciences, Seoul, Korea.
authors.forename: Eung-Ho
authors.initials: EH
authors.lastname: Cho
authors.affiliation: Department of Pathology, Korea Cancer Center Hospital, Korea Institute of Radiological & Medical Sciences, Seoul, Korea.
authors.forename: Sun Hoo
authors.initials: SH
authors.lastname: Park
authors.affiliation: Department of Surgery, Kangwon National University Hospital, Chuncheon, Korea.
authors.forename: Sung Bae
authors.initials: SB
authors.lastname: Park
authors.affiliation: Department of Surgery, Kangwon National University Hospital, Chuncheon, Korea.
authors.forename: Seong Kweon
authors.initials: SK
authors.lastname: Hong
authors.affiliation: Department of Surgery, Kangwon National University Hospital, Chuncheon, Korea.
authors.forename: Gibong
authors.initials: G
authors.lastname: Chae
keywords: Cholangiocarcinoma; Cluster of Differentiation 44 (CD44); Hepatocellular carcinoma; Neoplastic stem cells