title: Elevation of serum KL-6 mucin levels in patients with cholangiocarcinoma.
abstract: OBJECTIVE
  KL-6 mucin is a type of MUC1 mucin. Previous immunohistochemical studies by the authors revealed that, in liver cancer tissues, KL-6 mucin expressed only in intrahepatic cholangiocarcinoma (CC) but not in hepatocellular carcinoma (HCC). The current study performed serological analysis to evaluate KL-6 mucin levels in sera from various liver cancer patients and healthy individuals.
  
  
  METHODS
  Enzyme-linked immunosorbent assay was used to measure KL-6 mucin levels in sera from 8 CC patients, 27 HCC patients, 30 metastatic liver cancer (MC) patients, and 19 healthy individuals.
  
  
  RESULTS
  Serum KL-6 mucin levels were significantly higher in CC patients than in healthy individuals (p<0.0001), HCC patients (p<0.0001), and MC patients (p<0.001). Receiver operating characteristic analysis determined the cut-off level of serum KL-6 mucin levels to be 240 U/mL (CC vs. healthy, p<0.001) or 248 U/mL (CC vs. HCC, p<0.001). Using 248 U/mL as a cut-off value, the positive rate for CC patients, healthy individuals, and HCC patients was 100.0%, 15.8%, and 18.5%, respectively.
  
  
  CONCLUSIONS
  Elevation of serum KL-6 levels was detectable in CC patients. Thus, KL-6 might be a useful serological marker to distinguish CC patients from HCC patients.
authors.affiliation: Hepato-Biliary-Pancreatic Surgery Division, Department of Surgery, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
authors.forename: Huanli
authors.initials: H
authors.lastname: Xu
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Inagaki
authors.forename: Wei
authors.initials: W
authors.lastname: Tang
authors.forename: Qian
authors.initials: Q
authors.lastname: Guo
authors.forename: Fengshan
authors.initials: F
authors.lastname: Wang
authors.forename: Yasuji
authors.initials: Y
authors.lastname: Seyama
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Midorikawa
authors.forename: Ruoyan
authors.initials: R
authors.lastname: Gai
authors.forename: Noribim
authors.initials: N
authors.lastname: Kokudo
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Sugawara
authors.forename: Munehiro
authors.initials: M
authors.lastname: Nakata
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Makuuchi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008099:Liver / Q000378:metabolism; D008113:Liver Neoplasms / Q000097:blood*; D008297:Male; D008875:Middle Aged; D018396:Mucin-1 / Q000097:blood*; D012372:ROC Curve
chemical_list: C060192:MUC1 protein, human; D018396:Mucin-1