BILIARY CARCINOEMBRYONIC ANTIGEN LEVELS ARE A MARKER FOR CHOLANGIOCARCINOMA

BACKGROUND: Cholangiocarcinoma develops in 5% to 15% of patients with choledochal cysts, sclerosing cholangitis, and intrahepatic stones. Th e detection of cholangiocarcinoma in patients with premalignant biliar y conditions has been difficult. Serum levels of carcinoembryonic anti gen (CEA) have been neither sensitive nor specific for the diagnosis o f cholangiocarcinoma. However, CEA has been shown to be present in cho langiocarcinomas by immunohistochemical staining. Therefore, we measur ed the level of CEA excreted in bile in patients with benign stricture s, premalignant biliary diseases, and cholangiocarcinoma. PATIENTS AND METHODS: Bile was obtained from transhepatic stents in patients with benign biliary strictures (34), choledochal cysts (5), primary scleros ing cholangitis (6), intrahepatic cholelithiasis (5), and perihilar ch olangiocarcinoma (25). Samples were analyzed for CEA using a solid pha se, two-site immunoenzymetric assay. RESULTS: Biliary CEA levels were significantly elevated (P<0.01) in patients with cholangiocarcinoma (5 0.2 +/- 5.8 ng/mL) and intrahepatic cholelithiasis (57.4 +/- 10.4 ng/m L) compared with patients with benign strictures (10.1 +/- 3.9 ng/mL). Patients with sclerosing cholangitis (21.6 +/- 3.9 ng/mL) and choledo chal cysts (20.0 +/- 16.5 ng/mL) had intermediate levels. In 5 patient s undergoing resection of perihilar cholangiocarcinomas, the mean bili ary CEA level decreased from a preoperative level of 46.8 +/- 6.7 ng/m L to a postoperative level of 11.3 +/- 5.6 ng/mL (P<0.02). In 4 patien ts with progression of cholangiocarcinoma, biliary CEA increased from a mean of 53.3 +/- 6.9 ng/mL to 98.3 +/- 12.2 ng/mL (P<0.02) over a me an interval of 9.5 months. CONCLUSIONS: Increased levels of CEA can be detected in the bile of patients with chlolangio-carcinoma. Monitorin g these levels may have a role in the management of cholangiocarcinoma as well as premalignant biliary conditions such as choledochal cysts and sclerosing cholangitis.