title: Many patients with primary sclerosing cholangitis and increased serum levels of carbohydrate antigen 19-9 do not have cholangiocarcinoma.
abstract: OBJECTIVE
  Patients with primary sclerosing cholangitis (PSC) have an increased incidence of cholangiocarcinoma (CCA). Carbohydrate antigen 19-9 (CA 19-9) is the main serum marker used to diagnose CCA, although increased levels of CA 19-9 are also associated with other hepatic complications. We evaluated the long-term outcomes in patients with PSC and significant increases in levels of CA 19-9.
  
  
  METHODS
  We analyzed data from all Mayo Clinic patients with PSC and serum levels of CA 19-9 greater than 129 U/mL from 2000-2010 (n = 73). We reviewed patients' records for CCA diagnosis, other malignancies, recurrent bacterial cholangitis, and persistent cholestasis.
  
  
  RESULTS
  Thirty-seven percent of patients reviewed had no evidence of CCA after a median follow-up time of 30 months. The initial levels of CA 19-9 from patients without CCA were significantly lower than those from patients with CCA (286 vs 895 U/mL, P < .0001). At the start of the study, patients without CCA were more likely to have cirrhosis, compared with patients with CCA (48% vs 24%, P = .03), and lower levels of bilirubin (2 vs 6.8 mg/dL, P = .003), compared with patients with CCA. No factors known to affect CA 19-9 levels were identified in 33% of patients without CCA; endoscopic treatment and recurrent bacterial cholangitis were associated with levels of CA 19-9 in 26% and 22% of these patients, respectively.
  
  
  CONCLUSIONS
  Thirty-seven percent of patients with PSC who have serum levels of CA 19-9 greater than 129 U/mL do not have CCA. Additional studies should be performed to determine the outcomes of these patients.
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: Emmanouil
authors.initials: E
authors.lastname: Sinakos
authors.forename: Amy K
authors.initials: AK
authors.lastname: Saenger
authors.forename: Jill
authors.initials: J
authors.lastname: Keach
authors.forename: W Ray
authors.initials: WR
authors.lastname: Kim
authors.forename: Keith D
authors.initials: KD
authors.lastname: Lindor
mesh_terms: D000328:Adult; D000368:Aged; D018395:CA-19-9 Antigen / Q000097:blood*; D002241:Carbohydrates; D018281:Cholangiocarcinoma / Q000175:diagnosis* / Q000453:epidemiology*; D015209:Cholangitis, Sclerosing / Q000150:complications / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D044967:Serum / Q000737:chemistry
chemical_list: D018395:CA-19-9 Antigen; D002241:Carbohydrates