Portal de Periódicos da CAPES

Asbestos, Asbestosis, Smoking, and Lung Cancer. New Findings from the North American Insulator Cohort

2013; American Thoracic Society; Volume: 188; Issue: 1 Linguagem: Inglês

10.1164/rccm.201302-0257oc

1535-4970

Steven Markowitz, Stephen M. Levin, Albert Miller, Alfredo Morabia,

Interstitial Lung Diseases and Idiopathic Pulmonary Fibrosis

Rationale: Asbestos, smoking, and asbestosis increase lung cancer risk in incompletely elucidated ways. Smoking cessation among asbestos-exposed cohorts has been little studied.Objectives: To measure the contributions of asbestos exposure, asbestosis, smoking, and their interactions to lung cancer risk in an asbestos-exposed cohort and to describe their reduction in lung cancer risk when they stop smoking.Methods: We examined lung cancer mortality obtained through the National Death Index for 1981 to 2008 for 2,377 male North American insulators for whom chest X-ray, spirometric, occupational, and smoking data were collected in 1981 to 1983 and for 54,243 non–asbestos-exposed blue collar male workers from Cancer Prevention Study II for whom occupational and smoking data were collected in 1982.Measurements and Main Results: Lung cancer caused 339 (19%) insulator deaths. Lung cancer mortality was increased by asbestos exposure alone among nonsmokers (rate ratio = 3.6 [95% confidence interval (CI), 1.7–7.6]), by asbestosis among nonsmokers (rate ratio = 7.40 [95% CI, 4.0–13.7]), and by smoking without asbestos exposure (rate ratio = 10.3 [95% CI, 8.8–12.2]). The joint effect of smoking and asbestos alone was additive (rate ratio = 14.4 [95% CI, 10.7–19.4]) and with asbestosis, supra-additive (rate ratio = 36.8 [95% CI, 30.1–45.0]). Insulator lung cancer mortality halved within 10 years of smoking cessation and converged with that of never-smokers 30 years after smoking cessation.Conclusions: Asbestos increases lung cancer mortality among nonsmokers. Asbestosis further increases the lung cancer risk and, considered jointly with smoking, has a supra-additive effect. Insulators benefit greatly by quitting smoking.