Many patients with primary sclerosing cholangitis and increased serum levels of carbohydrate antigen 19-9 do not have cholangiocarcinoma.

Background & Aims 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 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.