Occupational exposures and lung cancer risk : an analysis of the CARTaGENE study
Background. Smoking is the strongest risk factor for lung cancer; however, other factors like the combinations of genetic predisposition, environmental exposures, and other lifestyle factors may also contribute to risk. This study aims to determine associations between prevalent occupational exposures and lung cancer risk. Methods. A case-cohort design was nested within the CARTaGENE study. Cases included all participants with an incident diagnosis of lung cancer from 2009-2016 (n=147). A sub-cohort of 1,032 individuals was sampled at baseline. The Canadian Job Exposure Matrix was used to determine occupational exposures in participants’ longest-held job. Twenty-eight agents with ≥5 exposed cases were retained for analysis. Separate multivariable logistic regression models with robust variance estimators were used to estimate odds ratios (OR) and 95% confidence intervals (CI) for the associations between each agent and lung cancer risk while controlling for established risk factors.  Results. Increased lung cancer risk was found among those exposed to ashes (OR=4.42; 95% CI: 1.75-11.15), calcium sulfate (OR=4.13; 95% CI: 1.20-14.20), hydrogen chloride (OR=3.79; 95% CI: 1.07-13.41), formaldehyde (OR=3.73; 95% CI: 1.51-9.19), cooking fumes (OR=2.92; 95% CI: 1.33-6.42), alkanes (OR=4.33; 95% CI:1.41-13.29), aliphatic aldehydes (OR=3.94; 95% CI: 1.41-10.98), and cleaning agents (OR=2.60; 95% CI: 1.50-4.52). A decrease in lung cancer incidence was found among participants exposed to carbon monoxide (OR=0.29; 95% CI:0.12-0.74) and polycyclic aromatic hydrocarbons from petroleum (OR=0.18; 95% CI: 0.05-0.60).  Conclusion.  Our findings support the role of several occupational agents, for which we have limited knowledge, in contributing to lung cancer risk.
Lung cancer Occupational exposure risk factor