Risk of bile duct cancer among printing workers exposed to 1,2‐dichloropropane and/or dichloromethane

Abstract

related to cumulative exposure to 1,2-DCP, but there remains some possibility that a portion of the risk is due to other unidentified substances. . Here, we report the risk of bile duct cancer among the same workers according to the cumulative years of exposure to two chemicals, dichloromethane (DCM) and 1,2-dichloropropane (1,2-DCP), using the standardized incidence rate (SIR) with reference to the nationwide incidence. Our goal was to evaluate separately the effect of DCM and 1,2-DCP on the risk of bile duct cancer and further evaluate these doseresponse relationships. In addition, we examined retrospectively patterns of the risk of bile duct cancer according to the calendar year in which observation started. Subjects and Methods Study populationWe identified this study population based on employee lists including one for vital status confirmation and information for current and former workers at a printing company in Osaka, Japan, which we obtained from the Ministry of Health, Labour and Welfare, Japan, and the printing company. The Abstract: Risk of bile duct cancer among printing workers exposed to 1,2-dichloropropane and/or dichloromethane: Tomotaka SOBUE, et al.

Cholangiocarcinoma Trends, Incidence, and Relative Survival in Khon Kaen, Thailand From 1989 Through 2013: A Population-Based Cancer Registry Study

“…32 Since O. viverrini infection is believed to be one of the risk factors of cholangiocarcinogenesis in Thailand, 33 a process that takes decades, time was also needed to evaluate the effectiveness of O. viverrini infection control (Figure 3 14,31 Our data show that, while the elderly continue to eat raw fish, the younger generations are avoiding eating it. The results indicate that O. viverrini infection occurred predominantly in the elderly over younger age groups.…”

Modifying effects of 1,2-dichloropropane on N-nitrosobis(2-oxopropyl)amine-induced cholangiocarcinogenesis in male Syrian hamsters

“…In addition, given that the occupational cholangiocarcinomas that occurred in the Japanese off-set printing plants were associated with inhalation exposure to 1,2-DCP, inhalation carcinogenicity studies are also needed to clarify the cholangiocarcinogenic potential of 1,2-DCP in hamsters. It remains unclear whether the occupational cholangiocarcinoma that occurred in Japan can be attributed to 1,2-DCP alone as workers with cholangiocarcinoma were exposed to more than 20 different chemicals (BenbrahimTallaa et al, 2014;Sobue et al, 2015). Dichloromethane (DCM) is another haloalkane associated with the occupational cholangiocarcinoma cases and was therefore classified as probably carcinogenic to human (Group 2A) (Benbrahim-Tallaa et al, 2014;Sobue et al, 2015).…”

“…It remains unclear whether the occupational cholangiocarcinoma that occurred in Japan can be attributed to 1,2-DCP alone as workers with cholangiocarcinoma were exposed to more than 20 different chemicals (BenbrahimTallaa et al, 2014;Sobue et al, 2015). Dichloromethane (DCM) is another haloalkane associated with the occupational cholangiocarcinoma cases and was therefore classified as probably carcinogenic to human (Group 2A) (Benbrahim-Tallaa et al, 2014;Sobue et al, 2015). In terms of cholangiocarcinogenicity in experimental rodents, similarly to 1,2-DCP, DCM did not induce cholangiocarcinogenesis in inhalation or drinking water carcinogenicity studies in mice, rats, or hamsters (Burek et al, 1984;Serota et al, 1986aSerota et al, , 1986b, while it induced hepatocellular tumors and lung tumors in inhalation carcinogenicity studies in mice (NTP, 1986b).…”

“…In terms of cholangiocarcinogenicity in experimental rodents, similarly to 1,2-DCP, DCM did not induce cholangiocarcinogenesis in inhalation or drinking water carcinogenicity studies in mice, rats, or hamsters (Burek et al, 1984;Serota et al, 1986aSerota et al, , 1986b, while it induced hepatocellular tumors and lung tumors in inhalation carcinogenicity studies in mice (NTP, 1986b). Given the fact that so far there is no experimental evidence for 1,2-DCP or DCM cholangiocarcinogenicity when administered alone and the possibility that the occurrence of occupational cholangiocarcinomas in Japan might be attributed to exposure to multiple chemicals (Benbrahim-Tallaa et al, 2014;Sobue et al, 2015), studies are needed to determine the carcinogenic effects of concurrent exposure to 1,2-DCP and DCM or other organic solvents contained in the stripers to which the workers with cholangiocarcinoma were exposed.…”

A trial to find appropriate animal models of dichloropropane‐induced cholangiocarcinoma based on the hepatic distribution of glutathione S‐transferases

“…Furthermore, GSTT1 has been reported to be overexpressed in the nuclei of mouse hepatocytes and is not expressed in the bile duct, while in humans, GSTT1 is expressed in the epithelial cells of the bile duct and some hepatocytes, in both the nucleus and cytoplasm 15) . Although DCP did not induce cholangiocarcinoma (CCA) after exposure of mice and rats for 2 years, it was thought to be the most probable cause of CCA in a case series in Japanese offsetcolor-proof printing workers 16) . These findings were attributed to the possible differences in GSTT1 distribution between rats/mice and humans as mentioned above.…”