title: Assessment of KL-6 as a tumor marker in patients with hepatocellular carcinoma.
abstract: OBJECTIVE
  To investigate the clinical significance of KL-6 as a tumor marker of HCC in two different ethnic groups with chronic liver disease consecutively encountered at outpatient clinics.
  
  
  METHODS
  Serum KL-6 was measured by the sandwich enzyme immunoassay method using the KL-6 antibody (Ab) as both the capture and tracer Ab according to the manufacturer's instructions (Eisai, Tokyo, Japan). Assessment of alpha fetoprotein (AFP) and protein induced vitamin K deficiency or absence (PIVKA-II) was performed in both groups using commercially available kits.
  
  
  RESULTS
  A significantly higher mean serum KL-6 (556+/-467 U/L) was found in HCC in comparison with non-HCC groups either with (391+/-176 U/L; P<0.001) or without (361+/-161 U/L; P<0.001) liver cirrhosis (LC). Serum KL-6 level did not correlate with either AFP or PIVKA-II serU/Levels. Using receiver operating curve analysis for KL-6 as a predictor for HCC showed that the area under the curve was 0.574 (95%CI = 0.50-0.64) and the KL-6 level that gave the best sensitivity (61%) was found to be 334 U/L but according to the manufacturer's instructions; a cut-off point of 500 U/L was used that showed the highest specificity (80%) in comparison with AFP and PIVKA-II (78% vs 72% respectively). Combining the values of the three markers improved specificity of AFP for HCC diagnosis from 78% for AFP alone; 93% for AFP plus PIVKA-II to 99% for both plus KL-6 value (P<0.001). Mean serum alkaline phosphatase level was significantly higher in KL-6 positive (564+/-475) in comparison with KL-6 negative (505+/-469) HCC patients (P = 0.021), but such a difference was not found among non-HCC corresponding groups.
  
  
  CONCLUSIONS
  KL-6 is suggested as a tumor for HCC. Its positivity may reflect HCC-associated cholestasis and/or local tumor invasion.
authors.affiliation: Second Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto 390-8621, Japan.
authors.forename: Amal
authors.initials: A
authors.lastname: Gad
authors.forename: Eiji
authors.initials: E
authors.lastname: Tanaka
authors.forename: Akihiro
authors.initials: A
authors.lastname: Matsumoto
authors.forename: Moushira Abd-el
authors.initials: MA
authors.lastname: Wahab
authors.forename: Abd el-Hamid
authors.initials: Ael-H
authors.lastname: Serwah
authors.forename: Fawzy
authors.initials: F
authors.lastname: Attia
authors.forename: Khalil
authors.initials: K
authors.lastname: Ali
authors.forename: Howayda
authors.initials: H
authors.lastname: Hassouba
authors.forename: Abd el-Raoof
authors.initials: Ael-R
authors.lastname: el-Deeb
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Ichijyo
authors.forename: Takeji
authors.initials: T
authors.lastname: Umemura
authors.forename: Hidetomo
authors.initials: H
authors.lastname: Muto
authors.forename: Kaname
authors.initials: K
authors.lastname: Yoshizawa
authors.forename: Kendo
authors.initials: K
authors.lastname: Kiyosawa
mesh_terms: D000328:Adult; D000368:Aged; D000941:Antigens / Q000097:blood*; D000951:Antigens, Neoplasm / Q000097:blood; D015415:Biomarkers / Q000097:blood; D014408:Biomarkers, Tumor / Q000097:blood*; D006528:Carcinoma, Hepatocellular / Q000097:blood* / Q000175:diagnosis / Q000473:pathology; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D004534:Egypt; D005006:Ethnicity; D005260:Female; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D007124:Immunoenzyme Techniques; D007564:Japan; D008107:Liver Diseases / Q000097:blood; D008113:Liver Neoplasms / Q000097:blood* / Q000175:diagnosis / Q000473:pathology; D008297:Male; D008875:Middle Aged; D018396:Mucin-1; D009077:Mucins / Q000097:blood*; D011237:Predictive Value of Tests; D011498:Protein Precursors / Q000097:blood; D011516:Prothrombin; D012372:ROC Curve; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D000509:alpha-Fetoproteins / Q000378:metabolism
chemical_list: D000941:Antigens; D000951:Antigens, Neoplasm; D015415:Biomarkers; D014408:Biomarkers, Tumor; D006023:Glycoproteins; C060192:MUC1 protein, human; D018396:Mucin-1; D009077:Mucins; D011498:Protein Precursors; D011933:Reagent Kits, Diagnostic; D000509:alpha-Fetoproteins; C008208:acarboxyprothrombin; D011516:Prothrombin