Levels of Tobacco-specific Metabolites among Non-smoking Lung Cancer Cases at Diagnosis: Case-control Findings

Abstract

<b>Background:</b> Environmental tobacco smoking (ETS) significantly contributes to morbidity and mortality and isa known risk factor for lung cancer development in lifelong nonsmokers. The metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and its glucuronides (NNAL-Glucs) have now emerged as leading biomarkersfor the study of carcinogen exposure in non-smokers exposed to ETS. Materials and <br/><b>Methods</b>: We carried outour study on NNAL in the urine of non-smokers exposed to ETS and the association between ETS and lungcancer. Subjects were enrolled from 2008-2010. NNAL was analyzed for 74 non-smoking lung cancer and 85healthy controls. The main objective of this study was to provide an estimate of the risk of lung cancer fromexposure to ETS in the Korean population. <br/><b>Results</b>: The mean NNAL concentration in urine was significantlylower in non-smoking patient groups (n=74) than in control groups (n=85) (4.7±15.0 pg/mg, 6.5±17.9 pg/mg,respectively, Mann-Whitney U test, p<0.001). <br/><b>Conclusions</b>: The urine NNAL of non-smoking patients with lungcancer was not elevated with regard to the non-smoking control group. This may be due to life-style changesafter diagnosis. A prospective study will be needed to evaluate the association of NNAL and non-smoking lungcancer.