This summary table contains detailed information about research studies. Summary tables offer an informative look at the science behind many breast cancer guidelines and recommendations. However, they should be viewed with some caution. In order to read and interpret research tables successfully, it is important to understand some key concepts. Learn how to read a research table.
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Introduction: Smoking causes many types of cancer (including cancers of the lung, kidney and pancreas). However, findings on a possible link to breast cancer are mixed [1]. Some studies show smoking increases risk, while others do not.
Several studies have shown smoking before a first childbirth may increase the risk of breast cancer [2-7]. However, a meta-analysis of 11 studies that looked at smoking before the birth of a first child and breast cancer risk, found no link between the two [8].
More research is needed before solid conclusions can be drawn about a potential link between smoking and breast cancer.
Find information on secondhand smoke exposure (also called passive smoking) and the risk of breast cancer.
Learn about the strengths and weaknesses of different types of studies.
See how this risk factor compares with other risk factors for breast cancer.
Study selection criteria: Prospective cohort studies with at least 200 breast cancer cases and meta-analyses.
Table note: Relative risk above 1 indicates increased risk. Relative risk below 1 indicates decreased risk.
Study
|
Study Population
(number of participants)
|
Follow-up
(years)
|
Smoking exposure comparisons
|
Relative Risk of Breast Cancer in Smokers Compared to Nonsmokers,
RR (95% CI)
|
Prospective cohort studies
|
Nurses' Health Study [2]
|
111,140
(8,772 cases)
|
30
|
Current vs. never
|
1.09 (1.02-1.17)
|
Canadian National Breast Screening Study [3]
|
89,835
(4,445 cases)
|
16.1
|
Current vs. never
|
1.18 (1.09-1.27)
|
Women’s Health Initiative Observational Study [4]
|
79,990
(3,520 cases)
|
10.3
|
Current vs. never
|
1.16 (1.00-1.34)
|
California Teachers Study [5]
|
116,544
(2,005 cases)
|
5
|
Current vs. never
|
1.32 (1.10-1.57)
|
Iowa Women's Health Study [6]
|
37,105
(1,995 cases)
|
13
|
Current vs. never
|
1.19 (1.03-1.37)
|
Norwegian-Swedish Cohort Study [7]
|
102,098
(1,130 cases)
|
9.3
|
Current vs. never
|
1.17 (0.95-1.45)
|
Nurses' Health Study II [9]
|
112,844*
(1,007 cases)
|
10
|
Current vs. never
|
1.12 (0.92-1.37)
|
Ha et al. [10]
|
56,042
(906 cases)
|
15
|
Current vs. never
|
1.13 (0.96-1.32)
|
Norwegian study [11]
|
14,269
(603 cases)
|
27
|
Current vs. never
|
1.0 (0.8-1.2)
|
Japan Collaborative Cohort Study for Evaluation of Cancer Risk [12]
|
34,401
(208 cases)
|
7.9‡
|
Current vs. never
|
0.67 (0.32-1.38)
|
Meta-analyses
|
Collaborative Group on Hormonal Factors in Breast Cancer [13]
|
48 studies
|
|
Current vs. never
|
0.99NS
|
NS = No statistically significant increase or decrease in risk.
* Participants were mainly premenopausal.
† Estimated from person-years of follow-up time.
References
1. U.S. Department of Health and Human Services. The health consequences of smoking: A report of the Surgeon General. Atlanta, GA. U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health, 2004.
2. Xue F, Willett WC, Rosner BA, Hankinson SE, Michels KB. Cigarette smoking and the incidence of breast cancer. Arch Intern Med. 171(2):125-133, 2011.
3. Cui Y, Miller AB, Rohan TE. Cigarette smoking and breast cancer risk: update of a prospective cohort study. Breast Cancer Res Treat. 100(3):293-9, 2006.
4. Luo J, Margolis KL, Wactawski-Wende J, et al. Association of active and passive smoking with risk of breast cancer among postmenopausal women: a prospective cohort study. BMJ. 342:d1016, 2011.
5. Reynolds PR, Hurley S, Goldberg DE, et al. Active smoking, household passive smoking, and breast cancer: evidence from the California Teachers Study. J Natl Cancer Inst. 96(1):29-37, 2004.
6. Olson JE, Vachon CM, Vierhant RA, et al. Prepregnancy exposure to cigarette smoking and subsequent risk of postmenopausal breast cancer. Mayo Clin Proc. 80(11):1423-8, 2005.
7. Gram IT, Braaten T, Terry PD, et al. Breast cancer risk among women who start smoking as teenagers. Cancer Epidemiol Biomarkers Prev. 14(1):61-6, 2005.
8. Lawlor DA, Ebrahim S, Davey Smith G. Smoking before the birth of a first child is not associated with increased risk of breast cancer: findings from the British Women's Heart and Health Cohort Study and a meta-analysis. Br J Cancer. 91(3):512-8, 2004.
9. Al-Delaimy WK, Cho E, Chen WY, Colditz GA, Willet WC. A prospective study of smoking and risk of breast cancer in young adult women. Cancer Epidemiol Biomarkers Prev. 13(3):398-404, 2004.
10. Ha M, Mabuchi K, Sigurdson AJ, et al. Smoking cigarettes before first childbirth and risk of breast cancer. Am J Epidemiol. 166(1):55-61, 2007.
11. Engeland A, Andersen A, Haldorsen T, Tretli S. Smoking habits and risk of cancers other than lung cancer: 28 years' follow-up of 26,000 Norwegian men and women. Cancer Causes Control. 7(5):497-506, 1996.
12. Lin L, Kikuchi S, Tamakoshi K, et al. for the Japan Collaborative Cohort Study Group for Evaluation of Cancer Risk. Active smoking, passive smoking, and breast cancer risk: findings from the Japan Collaborative Cohort Study for Evaluation of Cancer Risk. J Epidemiol. 18(2):77-83, 2008.
13. Hamajima N, Hirose K, Tajima K, et al. for the Collaborative Group on Hormonal Factors in Breast Cancer. Alcohol, tobacco and breast cancer--collaborative reanalysis of individual data from 53 epidemiological studies, including 58,515 women with breast cancer and 95,067 women without the disease. Br J Cancer. 87(11):1234-45, 2002.
Updated 01/23/12
