Serum Tumor Markers for the Diagnosis of Cholangiocarcinoma in Primary Sclerosing Cholangitis

Background/aims: The diagnosis of cholangiocarcinoma in primary sclerosing cholangitis (PSC), even with the use of current imaging techniques and brush cytology, is difficult and particularly important in patients being assessed for liver transplantation. This study investigated the accuracy of serum levels of a combination of the tumor markers carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) in the diagnosis of cholangiocarcinoma in patients with PSC.

Methods: Seventy-four patients with PSC were studied. Fifteen patients had tumors (11 occult on imaging), 22 had severe PSC that necessitated transplantation (with explanted liver known to be free of tumor), and 37 patients had stable PSC.

Results: An index of the two serum tumor markers [using the formula CA19-9 + (CEA x 40)] gave an accuracy of 86% in diagnosis of cholangiocarcinoma, with 10 of the 15 cases of cholangiocarcinoma having an increased value compared with none in a group of 22 comparable cases with no tumor. In addition, 6 of the 11 patients with occult tumors had abnormal values. Ultrasonography, computerized tomographic scanning, and endoscopic retrograde cholangiopancreatography were poor predictors of the presence of tumor.

Conclusions: A combination of serum tumor markers will identify most occult tumors and will improve selection of appropriate cases for orthotopic liver transplantation.