Biliary carcinoembryonic antigen in the diagnosis of occult hepatic metastases from colorectal cancer

Background and Objectives: Twenty five percent of patients who undergo radical surgical treatment for colorectal cancer have occult hepatic metastases that become evident during the follow-up period. We evaluated whether biliary carcinoembryonic antigen (CEA) measurements could be used in these patients to diagnose occult hepatic metastases. Methods: Three groups of patients were enrolled in the study. The first group consisted of patients treated for lithiasis of the common bile duct, the second group was affected by colorectal cancer and evident hepatic metastases, and the third group of patients underwent radical surgical treatment for colorectal cancer but had no evident hepatic metastases. Results: In the first study group, mean biliary CEA level was 0.52 ng/mL (normal value: 0-5 ng/mL) (diagnostic accuracy: 100%), 83.3 ng/mL in the second group (diagnostic accuracy: 91%) and 3.9 ng/mL in the third group. We registered only one false-positive result in the third group, whereas biliary CEA level was above normal values in the three patients in whom hepatic metastases developed (diagnostic accuracy: 89.5%). Conclusions: This study suggests that biliary CEA determination could represent an important method to select patients affected by occult hepatic metastases for inclusion in appropriate treatment protocols.