title: Active and passive smoking and breast cancer risk in middle-aged Japanese women.
abstract: To examine the hypothesis that tobacco smoke is associated with the risk of female breast cancer, we estimated the relative risks of active and passive smoke in middle-aged Japanese women in a population-based prospective study. The cohort consisted of residents in 4 public health center areas, aged 40 to 59 years. A self-administered questionnaire survey was conducted in 1990. This analysis included 21,805 subjects, 180 of whom had developed breast cancer by December 31, 1999. When the reference was defined as never-active smokers without passive smoking, adjusted relative risks (RRs) were 1.9 (95% confidence interval [CI] = 1.0-3.6) in current active smokers, 1.2 (95% CI = 0.4-4.0) in ex-active smokers and 1.2 (95% CI = 0.8-1.6) in never-active smokers with passive smoking. The elevated risk for ever-smokers was clearly observed in premenopausal women at baseline (RR = 3.9, 95% CI = 1.5-9.9) but not in postmenopausal women (RR = 1.1, 95% CI = 0.5-2.5). In never-active smokers, the adjusted RR for passive smoking, residential or occupational/public tobacco smoke exposure was 1.1 (95% CI = 0.8-1.6). In premenopausal women, passive smoking increased the risk (RR = 2.6; 95% CI = 1.3-5.2) but not in postmenopausal women (RR = 0.7; 95% CI = 0.4-1.0). We conclude that tobacco smoking increases the risk of female breast cancer in premenopausal women.
authors.affiliation: Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo 104-0045, Japan. thanaoka@gan2.res.ncc.go.jp
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Hanaoka
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Tomotaka
authors.initials: T
authors.lastname: Sobue
authors.forename: Satoshi
authors.initials: S
authors.lastname: Sasaki
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Tsugane
mesh_terms: D001943:Breast Neoplasms / Q000453:epidemiology*; D005260:Female; D006306:Health Surveys; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008875:Middle Aged; D017698:Postmenopause; D017697:Premenopause; D012306:Risk; D012907:Smoking / Q000009:adverse effects*; D011795:Surveys and Questionnaires; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
chemical_list: D014028:Tobacco Smoke Pollution