Carcinoembryonic antigen (CEA) and CEA-related substances in the bile of patients with biliary diseases.

The levels of carcinoembryonic antigen (CEA) in the bile of 10 patients with biliary cancer and 9 patients with cholelithiasis were examined immunochemically by the Western blot analysis. All samples of bile from the patients with biliary cancer showed three bands that corresponded to CEA, nonspecific crossreacting antigen, and biliary glycoprotein 1, respectively. The upper band (CEA) disappeared from the bile of patients who underwent curative operations, but it persisted in the bile of patients who underwent noncurative operations. All samples of bile from the patients with cholelithiasis did not show the upper band (CEA), even in those samples that had high levels of CEA by the conventional enzyme immunoassay. We suggest that, in order to diagnose the presence of tumor, to assess the therapeutic efficacy of surgery, and to detect any residual tumor, not only should the level of bile CEA be measured but also a Western blot analysis of the bile should be performed since it is more reliable.