High prevalence of asbestos exposure in bile duct cancer patients

Background: Asbestos exposure is a well recognized risk factor in mesothelioma and lung cancer development but the association with other tumors, such as gastrointestinal and bile ducts cancers (BTC), is uncertain and has not been univocally demonstrated. Asbestos fibers can cross the alveolar barrier after inhalation and penetrate the gastrointestinal mucosa by ingestion. Than they can reach the interstitial environment, the circulatory system and are finally delivered to all tissues, including liver and bile ducts. This work aims at evaluating the potential correlation between previous asbestos exposure and BTC occurrence. Methods: Over the previous year, we carefully interviewed 70 consecutive BTC patients using a standardized questionnaire asking about their exposure to asbestos and other known risk factors linked to bile duct carcinogenesis. Results: In addition to the association with known risk factors for the onset of BTC, we observed occupational or household exposure to asbes-tos in 25 patients (36%), 11 of whom were intrahepatic (ICC), 8 extrahepatic (ECC) and 6 patients had gallbladder cancer (GBC). 11 patients did not have other certain risk factors. The remaining 14 patients presented HCV chronic infection, exposure to proven or suspected carcinogenic compounds, or primary sclerosing cholangitis. Occupational exposure occurred in 5/11 ICC and 4/8 ECC; household exposure was noticed in 7/11 ICC, 4/8 ECC and 6/6 GBC. Only one ICC patient had both exposure type. Conclusions: A substantial proportion of BTC patients had an history of asbestos exposure. Further studies could clarify this putative relation and perhaps explain the increasing incidence of ICC in Western countries observed during the last decades.