title: Cigarette smoking and risk of benign proliferative epithelial disorders of the breast in the Women's Health Initiative.
abstract: OBJECTIVE
  To investigate the association between cigarette smoking and risk of benign proliferative epithelial disorders (BPED) of the breast.
  
  
  METHODS
  We used data from an ancillary study of benign breast disease that is being conducted in the Women's Health Initiative randomized clinical trials among 68,132 postmenopausal women aged 50-79 at recruitment. After following the trial participants for an average of 7.8 years, we had ascertained 294 incident cases with atypical hyperplasia and 1,498 incident cases with non-atypical BPED of the breast. We used Cox proportional hazards models to estimate hazard ratios for the association between cigarette smoking and risk of BPED.
  
  
  RESULTS
  Smoking measures, including duration of smoking, intensity of smoking, pack-years of smoking, age at which smoking commenced, and years since quitting smoking, were not associated with risk of BPED overall or by histological subtypes.
  
  
  CONCLUSIONS
  The null association between cigarette smoking and risk of BPED of the breast suggests that the carcinogenic and antiestrogenic effects of cigarette smoking on the breast might counterbalance each other and that cigarette smoking might have no overall effects on BPED of the breast among postmenopausal women.
authors.affiliation: Department of Epidemiology and Population Health, Albert Einstein College of Medicine, 1300 Morris Park Ave, Belfer 1301, Bronx, NY 10461, USA. rohan@aecom.yu.edu
authors.forename: Yan
authors.initials: Y
authors.lastname: Cui
authors.forename: David L
authors.initials: DL
authors.lastname: Page
authors.forename: Rowan T
authors.initials: RT
authors.lastname: Chlebowski
authors.forename: Judith
authors.initials: J
authors.lastname: Hsia
authors.forename: F
authors.initials: F
authors.lastname: Allan Hubbell
authors.forename: Karen C
authors.initials: KC
authors.lastname: Johnson
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Rohan
mesh_terms: D000368:Aged; D001941:Breast Diseases / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology; D016021:Epidemiologic Studies; D004848:Epithelium / Q000473:pathology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D016730:Program Development; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D014481:United States / Q000453:epidemiology; D016387:Women's Health