Published in Cancer Detection and Prevention 2002; 26(2).

Risk factors for lung cancer among Canadian women who 4 have never smoked

Jinfu Hu MDa, Yang Mao PhDa, Dagny Dryer MD, FRCPCc, Kathy White BA, BEdb The Canadian Cancer Registries Epidemiology Research Group

a Centre for Chronic Disease Prevention and Control, Population and Public Health Branch. Health Canada, Tunney's Pasture AL060ICI, Ottawa, Ont, Canada KIA OL2 b Strategic Policy Directorate. Population and Public Health Branch. Health Canada, Tunney's Pasture AL060ICI. Ottawa, Ont., Canada KlA OL2 c Prince Edward Island Cancer Registry and Oncology Clinic, Charlottetown, PEl, Canada

Accepted 12 February 2002

Risk factors for lung cancer among women who had never smoked were assessed in a case-control study of 161 newly diagnosed histologically confirmed cases and 483 population controls between 1994 and 1997 in eight Canadian provinces. Measurement included socio-economic status, smoking habits, alcohol use, diet, residential and occupational histories and exposure to environmental tobacco smoke (ETS). Dose-response associations were observed for consumption of tea, adjusted odds ratios (ORs) 0.6 (95% confidence interval (CI) = 0.3-0.9) for 1-7 cups per week and 0.4 (95% CI = 0.2-0.7) for ≥8 cups per week (P = 0.0008), and smoked meat, adjusted ORs 1.3 (95% CI = 0.8-2.3) for 0.5 slice per week and 2.1 (95% CI = 1.1--4.0) for >0.5 slice per week (P = 0.02). Regular use of shortening in cooking was also related to lung cancer. Increased ORs with borderline significance were found for total consumption of meat, eggs or French fries and fried potatoes. Passive exposure to ETS at home (or at work) may be associated with lung cancer risk among never-smoker women; the adjusted ORs were 0.7 (95% CI = 0.2-2.3), 1.2 (95% CI = 0.4-3.2),1.5 (95% CI = 0.5-4.0) for 1-16, 17-30, and 31 or more years of combined residential and/or occupational ETS exposure, respectively, with a similar pattern for smoker-years of ETS exposure.

KEY WORDS: Risk factors, Lung cancer, Never-smokers, Odds ratio, Diet, Logistic regression.