Enviromental tobacco smoke and lung cancer risk in nonsmoking women

Background: Exposure to envionmental tobacco smoke (passive smoking )has been suggested to be a cause of lung cancer, although early epidemiologic studies have produced in-consistent result. Purpose: We conducted an epidemilogic case-control study to assess the relation-ship between exposure to envirmental tobacco smoke and lungcancer risk among women who have never smoked (i.e., having smoked for a total of <6 months or having smoked <100 cigrettes in their life-times). Methods: Case patients (n =210) were women with histologically confirmed primary carcinomas of thelung who were lkfetime nonsmokers. They were identified through hospitak tumor registries and the Florida Cancer Data system of the StatewideCancer Registry. Community-based control women (n = 301) were also lifetime nonsmokers and were indentified through randam-digit dialing. Details on childhood and adulthood exposures to enviromental tobacco smoke were ascertained through interviews with the study participants themselves or with surrogate respondents. risks were calculated interms of the reported years of exposure to cigarette smoke from each smoker in the household. Resuts: The risk of lung cancer more than doubled for women who reported 40 or more smoke- years of household exposure during adulthood (odds ratio [OR] = 2.4; 95 confidence interval [CI] =1.1-5.3) or 22 more smoke-years of exposure during childhood and adolescence (OR = 2.4; 95% CI = 1.1-5.4). Risks were higest for non-adenocarcinoma lung cancers, although modest elevations in risk were also observed for adenocarcinomas. When a surrogate respondent other than the patient's husband provided information on exposure, the risk estimates were considerably lower. Conclusion: Thes findings suggest thatlong-term exposure to environmental tobacco smoke increases the risk of lung cancer in women who have never smoked.[J Natl Cancer Inst 84:1417-1422, 1992]