Tobacco-related urinary biomarkers and lung cancer risk in women, a case-cohort analysis.

Abstract

The constituents of tobacco smoke that specifically contribute to lung cancer risk have yet to be fully identified. We evaluated associations between biomarkers of potentially harmful constituents-polycyclic aromatic hydrocarbons (PAHs), tobacco-specific nitrosamines (TSNAs), nicotine, and volatile organic compounds (VOCs)-and lung cancer incidence among US women. In a case-cohort study nested within the Sister Study (women aged 35 to 74 years at baseline, enrolled 2003 to 2009), data were obtained for a random subcohort and all remaining incident lung cancers through September 2017 (median follow-up 9.6 years), stratified by race and ethnicity (Hispanic, non-Hispanic Black, non-Hispanic White, others) and smoking status (current, former, never). The analytic sample included 356 cases and 433 non-cases. We quantified 30 biomarkers in baseline urine samples and calculated hazard ratios (HRs) for associations between one-unit increase in biomarker concentrations (log-scale) and lung cancer incidence using weighted Cox regression models adjusted for urinary creatinine and demographic, health, and lifestyle factors. Among women who were currently smoking at enrolment, positive associations were observed for biomarkers of PAHs (naphthalene, phenanthrene, pyrene, fluorene; HRs 1.4 to 5.3), TSNAs (particularly 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK); HRs : 1.3-2.2), and VOCs (xylene, acrylamide, acrylonitrile, 1,2-dibromoethane/vinyl-chloride/ethylene-oxide/acrylonitrile, acrolein, styrene/ethylbenzene, benzene, dimethylformamide/methylisocyanate, 1,3-butadiene, crotonaldehyde, isoprene; HRs : 1.6-4.4). Associations with biomarkers of most PAHs, NNK, xylene, and dimethylformamide/methylisocyanate remained after additional adjustment for smoking frequency, duration, and nicotine metabolites. In women who did not smoke, positive associations were observed for styrene/ethylbenzene and dimethylformamide/methylisocyanate biomarkers. Exposure to PAHs, TSNAs and several VOCs through tobacco smoking were associated with increased lung cancer risk among women.