RT Journal Article
SR Electronic
T1 Occupational exposure to asbestos and risk of cholangiocarcinoma: a population-based case–control study in four Nordic countries
JF Occupational and Environmental Medicine
JO Occup Environ Med
FD BMJ Publishing Group Ltd
SP oemed-2017-104603
DO 10.1136/oemed-2017-104603
A1 Andrea Farioli
A1 Kurt Straif
A1 Giovanni Brandi
A1 Stefania Curti
A1 Kristina Kjaerheim
A1 Jan Ivar Martinsen
A1 Pär Sparen
A1 Laufey Tryggvadottir
A1 Elisabete Weiderpass
A1 Guido Biasco
A1 Francesco Saverio Violante
A1 Stefano Mattioli
A1 Eero Pukkala
YR 2017
UL http://oem.bmj.com/content/early/2017/11/13/oemed-2017-104603.abstract
AB Objectives To assess the association between occupational exposure to asbestos and the risk of cholangiocarcinoma (CC).Methods We 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.Results We 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.Conclusions Our 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.