Premium
Active and passive smoking and breast cancer risk in middle‐aged Japanese women
Author(s) -
Hanaoka Tomoyuki,
Yamamoto Seiichiro,
Sobue Tomotaka,
Sasaki Satoshi,
Tsugane Shoichiro
Publication year - 2004
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.20709
Subject(s) - medicine , passive smoking , relative risk , breast cancer , confidence interval , tobacco smoke , prospective cohort study , cohort study , cohort , population , gynecology , cancer , obstetrics , demography , environmental health , sociology
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. © 2004 Wiley‐Liss, Inc.