The Proportion of Occupationally Related Cholangiocarcinoma: A Tertiary Hospital Study in Northeastern Thailand

Abstract

Northeastern Thailand registers the highest worldwide incidence of cholangiocarcinoma (CCA). Most of the cases are associated with liver flukes, while unknown causes comprise approximately 10–30% of cases, and these could be due to occupational exposures. Our aim was to determine the magnitude of occupational causes of CCA in a tertiary hospital in northeastern Thailand. We conducted a cross-sectional study with a sample of 220 patients between March and November 2021. Descriptive statistics were used to analyze the findings. Clinical information and telephone interviews were used to explore significant occupational histories. An occupational consensus meeting was held with an occupational physician, hepatobiliary surgeon, and industrial hygienist to decide on the final diagnosis. The response rate was 90.9% (200/220). Based on the medical records and telephone interviews, researchers found that 11 participants had significant exposure. After occupational consensus, it was agreed that the eleven had possible occupational causes, 5.5% (11/200)–54.5% (6/11) being due to asbestos fibers, 45.5% (5/11) due to dichloromethane, and 9.1% (1/11) due to 1,2-dichloropropane. Only 4% (8/200) had occupational histories collected by their treating physicians. Taken together, occupationally related CCA appears to have been underestimated, so improving occupational history taking is needed to properly identify and classify work-related CCA—both for patient treatment and occupational hazard prevention.

Mutational Landscape of Cholangiocarcinoma According to Different Etiologies: A Review

“…Notably, it was observed that iCCA incidence increased with cumulative exposure to 1,2-DCP (adjusted RR = 14.9, 95% CI 4.1-54.3 for middle-exposure category, and adjusted RR = 17.1, 95% CI 3.8-76.2 for high-exposure category), suggesting an exposure-response relationship [70]. The potential association between CCA development and 1,2-DCP and/or DCM exposure has been reinforced by further epidemiological studies reporting the occurrence of this malignancy in an additional 13 printing workers of other Japanese companies [71,72] and in 6 out of 11 Thai workers occupationally exposed to these substances [73].…”

“…Similarly, a second study nested in the Nordic Occupational Cancer (NOCCA) cohort and including 5430 CCA cases, reported an increased risk of CCA in subjects exposed to asbestos, with a stronger association for iCCA than eCCA [82]. More recently, a cross-sectional study in Thai CCA patients reported that 11 (5.5%) out of 200 cases had a possible occupational cause, with 6 (54.5%) cases related to asbestos exposure [73].…”