CCA Association With Occupations Examined

A systematic review appears to support the hypothesis that certain occupations place workers at heightened risk of developing cholangiocarcinoma (CCA), researchers report.

The authors of the study published in the Asian Pacific Journal of Cancer Prevention noted, “A cluster of occupational cases among Japanese workers at a small offset printing plant led to the hypotheses that occupational exposure was the root cause of this cancer,” possibly attributable to exposure to carcinogens that are often found at industrial work sites.

The investigators searched several databases for reports between 1980 and 2020 of cases of CCA, intrahepatic CCA (distinct from hepatocellular carcinoma), and extrahepatic CCA excluding the gallbladder, as well as reports on specific carcinogens or surrogates associated with occupations or industry titles. They identified 10 observational studies that met all the eligibility criteria.

“The possible carcinogens statistical significantly related to the incidence or mortality of CCA risk included 1,2-dichloropropane (the highest RR = 32.40, 95%CI=6.40-163.90), asbestos (the highest OR=4.81, 95 % CI =1.73-13.33), [and] endocrine-disrupting compounds (the highest OR =2.00, 95% CI=1.10-3.70),” the authors reported. These carcinogens are classified as International Agency for Research on Cancer (IARC) class 1, meaning there is strong evidence that they cause cancer, and 2A. Rotating shift work (the highest HR =1.97, 95%CI=1.02-3.79) was also found to be statistically significant in relation to mortality and incidence of CCA.

“ Despite the limited number of studies reviewed, the hypothesis of occupational risk for CCA was supported,” the authors wrote. “Occupational health and safety measures may decrease exposure to these carcinogens, and surveillance in high-risk occupations or industries is urgently needed to prevent and control CCA.”

—Rebecca Mashaw

Reference:

Seeherunwong A, Chaiear N, Khuntikeo N, Ekpanyaskul C, Cholangiocarcinoma attributed to occupation: a systematic review. Asian Pac J Cancer Prev. 2022;23(6):1837-1845.

DOI: 10.31557/APJCP.2022.23.6.1837