Time Course of Blood Parameters in Printing Workers with Cholangiocarcinoma

Time Course of Blood Parameters in Printing Workers with Cholangiocarcinoma: Shinji KUMAGAI, et al. Department of Occupational and Environmental Management, University of Occupational and Environmental Health, Japan— Objectives We previously reported a cluster of cholangiocarcinoma patients among proof‐printing workers who were exposed to 1,2‐DCP for a long term. The present study was conducted to evaluate blood parameters in these proof‐printing workers during and after exposure. Methods Health examination records during employment and after retirement were obtained for ten cholangiocarcinoma patients to analyze their blood parameters. The patients and/or their relatives were also interviewed about lifestyle and occupational history. Results All study patients were exposed to 1,2‐DCP for 6−17 years. Red blood cells, hemoglobin, hematocrit, total cholesterol, triglycerides, and fasting plasma glucose were within the standard ranges for almost all patients, but the γ‐glutamyl transpeptidase (γ‐GTP) levels exceeded the standard range during 1,2‐DCP exposure for six patients. Two of the six patients were diagnosed with cholangiocarcinoma during 1,2‐DCP exposure, and the other four patients were diagnosed 1−9 years after termination of exposure. The remaining four patients had γ‐GTP levels within the standard range during 1,2‐DCP exposure, but had increased γ‐GTP levels thereafter, and were diagnosed with cholangiocarcinoma 4−10 years after termination of exposure. Aspartate aminotransferase and alanine aminotransferase levels started to increase following the increase in γ‐GTP levels. Conclusions Workers exposed to 1,2‐DCP should be provided with periodic health examinations during and after exposure. In the examination, even small increases in γ‐GTP levels should be considered a signal of early development of cholangiocarcinoma.