This summary table contains detailed information about research studies. While viewing summary tables offers an informative glimpse at the science behind many breast cancer guidelines and recommendations, they should be viewed with some caution. There are a number of concepts you must understand to be able to successfully read and interpret research tables. To get some background information about understanding research tables, please see How to Read a Research Table.
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Introduction: Although smoking causes many types of cancer (including cancers of the lung, kidney and pancreas) there is little evidence that it increases the risk of breast cancer [1]. Several studies have shown smoking before a first childbirth may increase risk of breast cancer [2-5]. However, a recent meta-analysis of 11 studies that looked at smoking before the birth of a first child and risk of breast cancer, found no link between the two [6]. Although smoking can cause many types of cancer and other diseases, more research is needed before solid conclusions can be drawn about a potential link to breast cancer.
For information on the secondhand smoke exposure (also called passive smoking), see Table 22.
Find more information on 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: Available 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
|
Canadian National Breast Screening Study [2]
|
89,835
(4,445 cases) |
16.1 |
Current vs. never |
1.18 (1.09-1.27) |
Nurses' Health Study [7]
|
78,206
(3,140 cases) |
14 |
Current vs. never |
1.04 (0.94-1.15) |
| California Teachers Study [3] |
116,544
(2,005 cases)
|
5 |
Current vs. never |
1.32 (1.10-1.57) |
Iowa Women's Health Study [4]
|
37,105
(1,995 cases) |
13 |
Current vs. never |
1.19 (1.03-1.37)
|
Norwegian-Swedish Cohort Study [5]
|
102,098
(1,130 cases) |
9.3 |
Current vs. never |
1.17 (0.95-1.45) |
Nurses' Health Study II [8]
|
112,844*
(1,007 cases) |
10 |
Current vs. never |
1.12 (0.92-1.37) |
| Ha et al. [9] |
56,042
(906 cases)
|
15 |
Current vs. never |
1.13 (0.96-1.32) |
Norwegian study [10]
|
14,269
(603 cases)
|
27
|
Current vs. never
|
1.0 (0.8-1.2)
|
Japan Collaborative Cohort Study for Evaluation of Cancer Risk [11]
|
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 [12]
|
48 studies
|
|
Current vs. never
|
0.99NS
|
NS = No statistically significant increase or decrease in risk.
* Participants were mainly premenopausal during time period.
† 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. 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.
3. 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.
4. 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.
5. 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.
6. 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.
7. Egan KM, Stampfer MJ, Hunter D, et al. for the Nurses’ Health Study. Active and passive smoking in breast cancer: prospective results from the Nurses' Health Study. Epidemiology. 13(2):138-45, 2002.
8. 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.
9. 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.
10. 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.
11. 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.
12. 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. 2002 Nov 18;87(11):1234-45, 2002.
Updated 09/12/09
