Passive smoking at home and cancer risk: a population-based prospective study in Japanese nonsmoking women.
OBJECTIVE
To investigate the relationship between passive smoking at home and the incidence of various cancers in a population-based prospective study.


METHODS
The subjects were 9675 Japanese lifelong nonsmoking women aged over 40 years who lived in three municipalities of Miyagi Prefecture, and completed a self-administration questionnaire in 1984. During 9 years of follow-up, 426 cancers were identified by record linkage to the population-based cancer registry. The data were analyzed using the Cox proportional hazards model.


RESULTS
The age-adjusted relative risks (RR) and 95% confidence intervals (CI) of smoking-related cancers and lung cancer for women who had smoking husbands, compared with women whose husbands did not smoke, were 1.7 (0.94 2.9, p = 0.079) and 1.9 (0.81-4.4, p = 0.14), respectively. In contrast, a significant inverse association was observed for breast cancer, the RR (95% CI) was 0.58 (0.34-0.99, p = 0.047). After multivariate adjustment for confounding factors, the risks of smoking-related cancers and breast cancer were materially unchanged.


CONCLUSIONS
These results show that passive smoking may affect the risk of cancers other than lung cancer.
Nishino
Y
Y
Department of Social Medicine, Tohoku University, Graduate School of Medicine, Sendai, Japan. ynishino@mail.cc.tohoku.ac.jp
Tsubono
Y
Y
Tsuji
I
I
Komatsu
S
S
Kanemura
S
S
Nakatsuka
H
H
Fukao
A
A
Satoh
H
H
Hisamichi
S
S
D000367:Age Factors; D001943:Breast Neoplasms / Q000453:epidemiology / Q000209:etiology; D005191:Family Characteristics; D005260:Female; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008175:Lung Neoplasms / Q000453:epidemiology / Q000209:etiology; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology / Q000209:etiology*; D011446:Prospective Studies; D012004:Rectal Neoplasms / Q000453:epidemiology / Q000209:etiology; D012306:Risk; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
D014028:Tobacco Smoke Pollution