Search

Objectives: This study aimed to evaluate the relationship between cumulative exposure to 1,2-dichloropropane (1,2-DCP) and incidence risk of cholangiocarcinoma among workers in the offset proof-printing section of a small printing company in Osaka, Japan., Methods: We identified 95 workers of a printing company (78 men and 17 women) who had been exposed to 1,2-DCP between 1987 and 2006, and calculated the standardised incidence ratio (SIR) of cholangiocarcinoma from 1987 to 2012. We estimated cumulative exposure to 1,2-DCP and calculated SIRs in four exposure categories. We also calculated incidence rate ratios (RRs) adjusted by sex, age, calendar year and dichloromethane (DCM) exposure for three exposure categories using Poisson regression analysis., Results: Cumulative exposures to 1,2-DCP ranged from 32 to 3433 ppm-years (mean, 851 ppm-years) and the SIR was 1171 (95% CI 682 to 1875). In the analysis of the four exposure categories, SIRs increased significantly in the three highest exposure categories, but not in the lowest category. Adjusted RRs in the middle and high exposure categories were 14.9 (95% CI 4.1 to 54.3) and 17.1 (95% CI 3.8 to 76.2), respectively, in the analysis without lag time, and were 11.4 (95% CI 3.3 to 39.6) and 32.4 (95% CI 6.4 to 163.9), respectively, in the analysis with a 5-year lag. The trend analysis revealed a significant increase in RR in association with increasing cumulative exposure to 1,2-DCP. DCM exposure was not significantly associated with the development of cholangiocarcinoma., Conclusions: The present study demonstrated an exposure-response relationship between exposure to 1,2-DCP and the development of cholangiocarcinoma., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Objectives: We conducted a retrospective cohort study to examine the risk of bile duct cancer among current and former workers in the offset color proof printing department at a printing company in Osaka, Japan., Methods: Standardized incidence ratios (SIRs) between January 1, 1985, and December 31, 2012, were estimated for the cumulative years of exposure to two chemicals, dichloromethane (DCM) and 1,2-dichloropropane (1,2-DCP), using the national incidence level as a reference. In addition, we examined risk patterns by the calendar year in which observation started., Results: Among 106 workers with a total of 1,452.4 person-years of exposure, 17 bile duct cancer cases were observed, resulting in an estimated overall SIR of 1,132.5 (95% confidence interval (CI): 659.7-1,813.2). The SIR was 1,319.9 (95% CI: 658.9-2,361.7) for those who were exposed to both DCM and 1,2-DCP, and it was 1,002.8 (95% CI: 368.0-2,182.8) for those exposed to 1,2-DCP only. SIRs tended to increase according to years of exposure to 1,2-DCP but not DCM when a 5-year lag time was assumed. The SIRs were higher for the cohorts in which observation started in 1993-2000, particularly in cohorts in which it started in 1996-1999, compared with those in which it started before or after 1993-2000., Conclusions: We observed an extraordinarily high risk of bile duct cancer among the offset color proof printing workers. Elevated risk may be 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.

Background: An outbreak of cholangiocarcinoma occurred among workers in the offset color proof-printing department at a printing company in Japan. The aim of this study was to clarify the characteristics of the patients with cholangiocarcinoma., Methods: This was a retrospective study conducted in 13 Japanese hospitals between 1996 to 2013. The clinicopathological findings of cholangiocarcinoma developed in 17 of 111 former or current workers in the department were investigated. Most workers were relatively young., Results: The cholangiocarcinoma was diagnosed at 25-45 years old. They were exposed to chemicals, including dichloromethane and 1,2-dichloropropane. The serum γ-glutamyl transpeptidase activity was elevated in all patients. Dilated intrahepatic bile ducts without tumor-induced obstruction were observed in five patients. The cholangiocarcinomas arose from the large bile ducts. The precancerous or early cancerous lesions, such as biliary intraepithelial neoplasia and intraductal papillary neoplasm of the bile ducts, as well as non-specific bile duct injuries, such as fibrosis, were observed in various sites of the bile ducts in all eight patients for whom operative specimens were available., Conclusions: The present results showed that cholangiocarcinomas occurred at a high incidence in relatively young workers of a printing company, who were exposed to chemicals including chlorinated organic solvents., (© 2014 Japanese Society of Hepato-Biliary-Pancreatic Surgery.)