Occupational exposure to asbestos and risk of cholangiocarcinoma: a population-based case–control study in four Nordic countries

• Published in: Occupational and environmental medicine (London, England) Vol. 75; no. 3; pp. 191 - 198
• Main Authors: Farioli, Andrea, Straif, Kurt, Brandi, Giovanni, Curti, Stefania, Kjaerheim, Kristina, Martinsen, Jan Ivar, Sparen, Pär, Tryggvadottir, Laufey, Weiderpass, Elisabete, Biasco, Guido, Violante, Francesco Saverio, Mattioli, Stefano, Pukkala, Eero
• Format: Journal Article
• Language: English
• Published: England BMJ 01.03.2018; BMJ Publishing Group LTD; BMJ Publishing Group
• Series: Original article
• Subjects: Aged; Aged, 80 and over; Alcohol; Asbestos; Asbestos - adverse effects; Bile Duct Neoplasms - chemically induced; Bile Duct Neoplasms - epidemiology; Cancer; Case studies; Case-Control Studies; Censuses; Cholangiocarcinoma; Cholangiocarcinoma - chemically induced; Cholangiocarcinoma - epidemiology; Codes; Disease; Emigration; Epidemiology; Exposure; Female; Finland - epidemiology; Health risk assessment; Humans; Iceland - epidemiology; Logistic Models; Male; Medicin och hälsovetenskap; Mesothelioma; Middle Aged; Mortality; Norway - epidemiology; Occupational exposure; Occupational Exposure - adverse effects; Occupational Exposure - statistics & numerical data; Occupational health; Occupations; Odds Ratio; ORIGINAL ARTICLE; Population; Population studies; Population-based studies; Printing industry; Publishing - statistics & numerical data; Regression analysis; Regression models; Risk Factors; Studies; Sweden - epidemiology; VOCs; Volatile organic compounds; Workers; Workplace; Sweden; Norway; Iceland; Finland; Denmark
• ISSN: 1351-0711; 1470-7926; 1470-7926
• DOI: 10.1136/oemed-2017-104603

ObjectivesTo assess the association between occupational exposure to asbestos and the risk of cholangiocarcinoma (CC).MethodsWe conducted a case–control study nested in the Nordic Occupational Cancer (NOCCA) cohort. We studied 1458 intrahepatic CC (ICC) and 3972 extrahepatic CC (ECC) cases occurring among subjects born in 1920 or later in Finland, Iceland, Norway and Sweden. Each case was individually matched by birth year, gender and country to five population controls. The cumulative exposure to asbestos (measured in fibres (f)/ml × years) was assessed by applying the NOCCA job-exposure matrix to data on occupations collected during national population censuses (conducted in 1960, 1970, 1980/81 and 1990). Odds ratios (OR) and 95% CI were estimated using conditional logistic regression models adjusted by printing industry work.ResultsWe observed an increasing risk of ICC with cumulative exposure to asbestos: never exposed, OR 1.0 (reference category); 0.1–4.9 f/mL × years, OR 1.1 (95% CI 0.9 to 1.3); 5.0–9.9 f/mL × years, OR 1.3 (95% CI 0.9 to 2.1); 10.0–14.9 f/mL × years, OR 1.6 (95% CI 1.0 to 2.5); ≥15.0 f/mL × years, OR 1.7 (95% CI 1.1 to 2.6). We did not observe an association between cumulative asbestos exposure and ECC.ConclusionsOur study provides evidence that exposure to asbestos might be a risk factor for ICC. Our findings also suggest that the association between ECC and asbestos is null or weaker than that observed for ICC. Further studies based on large industrial cohorts of asbestos workers and possibly accounting for personal characteristics and clinical history are needed.