title: Is a raised CA 19-9 level diagnostic for a cholangiocarcinoma in patients with no history of sclerosing cholangitis ?
abstract: OBJECTIVE
  A cholangiocarcinoma, the second most common primary hepatic malignancy, can present with diagnostic dilemmas. The aim of this study is to assess the role of CA 19-9 in patients with a cholangiocarcinoma without primary sclerosing cholangitis.
  
  
  METHODS
  The prospectively collected information on patients with biopsy-proven cholangiocarcinomas who had the CA 19-9 level measured was obtained (n = 68) from our computer database and medical records. These patients were compared with patients who had benign liver tumours (n = 25) and benign bile duct strictures (n = 13) who also had their CA 19-9 concentration measured.
  
  
  RESULTS
  Sensitivity and specificity of CA 19-9 in the diagnosis of a cholangiocarcinoma were 77.9 and 76.3%, respectively, when using a cut-off value of 35 kU/l, while sensitivity and specificity were 67.5 and 86.8%, respectively, when the cut-off value was raised to 100 kU/l. The specificity was found to be higher in patients with peripheral cholangiocarcinomas (96%) using a CA 19-9 cut-off value >100 kU/l. A CA 19-9 value >600 kU/l was associated with non-resectable tumours (p = 0.05).
  
  
  CONCLUSIONS
  This study demonstrates that CA 19-9 is a useful adjunct in the diagnosis of cholangiocarcinomas without primary sclerosing cholangitis, especially in the diagnosis of peripheral cholangiocarcinomas. However, it does not provide a reliable guide for the pathological staging of these tumours.
authors.affiliation: Liver Unit, Queen Elizabeth Hospital, University Hospital Birmingham NHS Foundation Trust, Birmingham, UK.
authors.forename: Abraham R
authors.initials: AR
authors.lastname: John
authors.forename: Koroush S
authors.initials: KS
authors.lastname: Haghighi
authors.forename: Phillippe
authors.initials: P
authors.lastname: Taniere
authors.forename: M Emad
authors.initials: ME
authors.lastname: Esmat
authors.forename: Yu Meng
authors.initials: YM
authors.lastname: Tan
authors.forename: Simon R
authors.initials: SR
authors.lastname: Bramhall
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000097:blood*; D001653:Bile Ducts, Intrahepatic; D014408:Biomarkers, Tumor / Q000097:blood; D001706:Biopsy; D018395:CA-19-9 Antigen / Q000097:blood*; D018281:Cholangiocarcinoma / Q000097:blood*; D015209:Cholangitis, Sclerosing; D006801:Humans; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor; D018395:CA-19-9 Antigen