Cigarette smoking and the incidence of breast cancer

January 01, 0001

Cigarette smoking and the incidence of breast cancer

Tobacco smoke contains carcinogens, which may increase the risk of breast cancer (BC). Conversely, cigarette smoking also has antiestrogenic effects. These US authors report results from the prospective cohort of 111,140 participants of the Nurses' Health Study from 1976 to 2006 for active smoking and 36,017 women from 1982 to 2006 for passive smoking.

They found: "During 3,005,863 person-years of follow-up, 8772 incident cases of invasive BC were reported. After adjustment for potential confounders, the hazard ratio (HR) of BC was 1.06% for ever smokers relative to never smokers. Breast cancer incidence was associated with a higher quantity of current and past smoking, younger age at smoking initiation, longer duration of smoking, and more pack-years of smoking. Premenopausal smoking was associated with a slightly higher incidence of BC (HR, 1.11 for every increase of 20 pack-years), especially smoking before first birth (1.18 for every increase of 20 pack-years). Conversely, the direction of the association between postmenopausal smoking and BC was inverse (0.93 for every increase of 20 pack-years). Passive smoking in childhood or adulthood was not associated with BC risk."

The authors concluded: "Active smoking, especially smoking before the first birth, may be associated with a modest increase in the risk of BC."

Yet another cancer risk associated with smoking.

For the full abstract, click here.

Arch Intern Med 171(2):125-133, 24 January 2011
© 2011 to the American Medical Association
Cigarette Smoking and the Incidence of Breast Cancer. Fei Xue, Walter C. Willett, Bernard A. Rosner, Susan E. Hankinson, Karin B. Michels. Correspondence to Dr.Xue: [email protected]

Category: Z. Social Problems. Keywords: cigarette smoking, tobacco, breast cancer, prospective cohort study, journal watch.
Synopsis edited by Dr Linda French, Toledo, Ohio. Posted on Global Family Doctor 8 February 2011

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