Women exposed to tobacco smoke are 2.6 times more likely to contract breast cancer

Women exposed to tobacco smoke are 2.6 times more likely to contract breast cancer, according to the results of a survey conducted by the Japanese Ministry of Health, Labor and Welfare.  Adverse effects from passive smoking were particularly damaging among premenopausal women.

The research team led by Shoichiro Tsugane, a division chief of the National Cancer Center, surveyed about 20,000 women in their 40s and 50s. The group researched relationships between lifestyle and such diseases as cancer from 1990 for about 10 years.

The results of the survey showed that the incidence of breast cancer among premenopausal female smokers was 3.6 times higher than that for postmenopausal female nonsmokers, while passive smoking was found to increase the risk of contracting breast cancer among nonsmokers by 260 percent.

As female hormones linked with oncogenesis in breasts are more active before menopause, women who have not undergone the process are seen as more likely to suffer detrimental effects from passive smoking. 

Tomoyuki Hanaoka, section head of the cancer center's epidemiology and prevention division and a member of the team, said, "The survey results have shown that avoiding passive smoking as well as active smoking is a preventive measure against breast cancer."

Courtesy Joseph W. Cherner at:

Parts Excerpted from the Yomiuri Shimbun, 12/5/04