Screening and surveillance for occupational cholangiocarcinoma in workers exposed to organic solvents

Purpose: This study aimed to establish an efficient strategy for screening and surveillance for occupational cholangiocarcinoma. Methods: We evaluated the consecutive changes in laboratory findings during regular health examinations and in abdominal ultrasonography findings before the diagnosis of occupational cholangiocarcinoma in nine patients. The results of laboratory tests and abdominal ultrasonography at the time of diagnosis were also examined. Results: In all patients, the serum γ-glutamyl transpeptidase (γ-GTP) activity increased several years before the diagnosis of cholangiocarcinoma. The serum alanine aminotransferase (ALT) activity also increased several years before the diagnosis, following an increase in the serum aspartate aminotransferase (AST) activity in most patients. Abdominal ultrasonography before the diagnosis revealed regional dilatation of the bile ducts, which continued to enlarge. At the time of diagnosis, the γ-GTP, AST, and ALT activities were increased in nine, seven, and seven patients, respectively. The regional dilatation of bile ducts without tumor-induced stenosis, dilated bile ducts due to tumor-induced stenosis, space-occupying lesions, and/or lymph node swelling were observed. The serum concentrations of carbohydrate antigen 19-9 (CA 19-9) and/or carcinoembryonic antigen (CEA) were increased in all patients. Conclusions: Regular health examinations with a combination of ultrasonography and laboratory tests including the γ-GTP, AST, ALT, CA 19-9, and CEA levels are useful for screening and surveillance for occupational cholangiocarcinoma.