Occupational exposure to endotoxins and lung cancer risk: results of the ICARE Study

Abstract

ObjectivesTo investigate the role of occupational exposure to endotoxins in lung cancer in a French population-based case–control study (ICARE (Investigation of occupational and environmental causes of respiratory cancers)).MethodsDetailed information was collected on the occupational history and smoking habits from 2926 patients with histologically confirmed lung cancer and 3555 matched controls. We evaluated each subject’s endotoxin exposure after cross referencing International Standard Classification of Occupations (ISCO) codes (for job tasks) and Nomenclature d'Activités Françaises (NAF) codes (for activity sectors). Endotoxin exposure levels were attributed to each work environment based on literature reports. ORs and 95% CIs were estimated using unconditional logistic regression models and controlled for main confounding factors.ResultsAn inverse association between exposure to endotoxins and lung cancer was found (OR=0.80, 95% CI 0.66 to 0.95). Negative trends were shown with duration and cumulative exposure, and the risk was decreased decades after exposure cessation (all statistically significant). Lung cancer risk was particularly reduced among workers highly exposed (eg, in dairy, cattle, poultry, pig farms), but also in those weakly exposed (eg, in waste treatment). Statistically significant interactions were shown with smoking, and never/light smokers were more sensitive to an endotoxin effect than heavy smokers (eg, OR=0.14, 95% CI 0.06 to 0.32 and OR=0.80, 95% CI 0.45 to 1.40, respectively, for the quartiles with the highest cumulative exposure, compared with those never exposed). Pronounced inverse associations were shown with adenocarcinoma histological subtype (OR=0.37, 95% CI 0.25 to 0.55 in the highly exposed).ConclusionsOur findings suggest that exposure to endotoxins, even at a low level, reduces the risk of lung cancer.

<p>In Patients with Mild-to-Moderate COPD, Tobacco Smoking, and Not COPD, Is Associated with a Higher Risk of Cardiovascular Comorbidity</p>

“…6 In addition, the protective role of farming on comorbidities such as lung cancer has also been previously reported. 26 A survival bias is however not excluded in this population.…”

Agriculture Occupational Exposures and Factors Affecting Health Effects

“…Another investigation assessing the impact of occupational endotoxin exposure and lung cancer risk also identified a protective effect for farming exposures. In this ICARE Study (Investigation of occupational and environmental causes of respiratory cancers; a French population-based study), high exposure settings, including dairy, cattle, swine, and poultry farms, were associated with reduced risk for disease even decades after exposures ceased, with greater exposure durations also associated with greater reductions in lung cancer risk [46]. Similar to the findings of the AGRICAN cohort, the strongest inverse relationships were with lung adenocarcinomas.…”

Occupational exposure to textile dust and lung cancer risk: Results from the ICARE Study

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