title: Cigarette smoking and breast cancer.
abstract: OBJECTIVE
  To investigate cigarette smoking in relation to the risk of breast cancer.
  
  
  METHODS
  Interviews with women referred for mammography.
  
  
  METHODS
  Hjørring District Hospital, a public, population based hospital in Denmark.
  
  
  METHODS
  3240 women aged 15-92 years referred for mammography during 1 June 1989 to 1 November 1991.
  
  
  METHODS
  Smoking, parity, age, reason for referral, breast cancer.
  
  
  RESULTS
  In a multiple logistic regression analysis adjusted for six variables a pronounced increased risk of breast cancer was found in women who had smoked for over 20 years, and this was significant in women who had smoked for over 30 years (odds ratio 1.6, 95% confidence interval 1.1 to 2.3). The median age of women with breast cancer was 59 (range 31-81) years for smokers and 67 (38-92) years for nonsmokers. The difference of eight years between the median ages was significant (P < 0.01).
  
  
  CONCLUSIONS
  Smoking may increase the risk of breast cancer after 30 years of smoking.
authors.affiliation: Department of Radiology, Hjørring District Hospital, Denmark.
authors.forename: K
authors.initials: K
authors.lastname: Bennicke
authors.forename: C
authors.initials: C
authors.lastname: Conrad
authors.forename: S
authors.initials: S
authors.lastname: Sabroe
authors.forename: H T
authors.initials: HT
authors.lastname: Sørensen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology*; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D016015:Logistic Models; D008327:Mammography; D008875:Middle Aged; D015995:Prevalence; D012017:Referral and Consultation; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*