Xue Fei, Willett Walter C, Rosner Bernard A, Hankinson Susan E, Michels Karin B
Obstetrics and Gynecology Epidemiology Center, Department of Obstetrics and Gynecology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
Arch Intern Med. 2011 Jan 24;171(2):125-33. doi: 10.1001/archinternmed.2010.503.
Tobacco smoke contains carcinogens, which may increase the risk of breast cancer (BC). Conversely, cigarette smoking also has antiestrogenic effects, which may reduce the risk of BC. The association between smoking and BC remains controversial.
Prospective cohort study 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.
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% (95% confidence interval [CI], 1.01%-1.10%) for ever smokers relative to never smokers. Breast cancer incidence was associated with a higher quantity of current (P for trend = .02) and past (P for trend = .003) smoking, younger age at smoking initiation (P for trend = .01), longer duration of smoking (P for trend = .01), and more pack-years of smoking (P for trend = .005). Premenopausal smoking was associated with a slightly higher incidence of BC (HR, 1.11; 95% CI, 1.07-1.15 for every increase of 20 pack-years), especially smoking before first birth (1.18; 1.10-1.27 for every increase of 20 pack-years). Conversely, the direction of the association between postmenopausal smoking and BC was inverse (0.93; 0.85-1.02 for every increase of 20 pack-years). Passive smoking in childhood or adulthood was not associated with BC risk.
Active smoking, especially smoking before the first birth, may be associated with a modest increase in the risk of BC.
烟草烟雾中含有致癌物，可能会增加患乳腺癌（BC）的风险。相反，吸烟也具有抗雌激素作用，可能会降低患BC的风险。吸烟与BC之间的关联仍存在争议。
对1976年至2006年护士健康研究中的111140名参与者进行主动吸烟的前瞻性队列研究，以及对1982年至2006年的36017名女性进行被动吸烟的前瞻性队列研究。
在3005863人年的随访期间，报告了8772例浸润性BC病例。在对潜在混杂因素进行调整后，曾经吸烟者患BC的风险比（HR）相对于从不吸烟者为1.06%（95%置信区间[CI]，1.01%-1.10%）。乳腺癌发病率与当前吸烟量（趋势P值=0.02）和过去吸烟量（趋势P值=0.003）增加、开始吸烟时年龄较小（趋势P值=0.01）、吸烟持续时间较长（趋势P值=0.01）以及吸烟包年数较多（趋势P值=0.005）有关。绝经前吸烟与BC发病率略高相关（HR，1.11；每增加20包年，95%CI为1.07-1.15），尤其是首次生育前吸烟（每增加20包年，1.18；1.10-1.27）。相反，绝经后吸烟与BC之间的关联方向相反（每增加20包年，0.93；0.85-1.02）。儿童期或成年期的被动吸烟与BC风险无关。
主动吸烟，尤其是首次生育前吸烟，可能与BC风险适度增加有关。
