Active and Passive Smoking and Breast Cancer Risk in Middle-Aged Japanese Women

Int J Cancer. 2005 Mar 20;114(2):317-22. doi: 10.1002/ijc.20709.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Breast Neoplasms / epidemiology*
  • Female
  • Health Surveys
  • Humans
  • Japan / epidemiology
  • Middle Aged
  • Postmenopause
  • Premenopause
  • Risk
  • Smoking / adverse effects*
  • Surveys and Questionnaires
  • Tobacco Smoke Pollution / adverse effects*

Substances

  • Tobacco Smoke Pollution