Tobacco Smoke

At a Glance

Tobacco smoke contains chemicals that have been linked to cancer, from both active and passive smoking. The use of cigarettes has been linked to stroke, coronary heart disease, and many cancers, including lung cancer and breast cancer.

What is tobacco smoke?

Tobacco smoke is a mixture of gases and chemicals that is sent into the air during the burning of tobacco products or from the smoke that is exhaled by a smoker. The smoke that is present in the environment contains multiple chemicals linked to breast cancer, such as benzene and vinyl chloride, both designated as known carcinogens by the International Agency for Research on Cancer or the National Toxicology Program,[1],[2],[3] as well as 1, 3-butadiene, toluene, and nicotine-derived nitrosamine ketone (NNK) that may cause mammary tumors in animals.[4] NNK is a tobacco-specific carcinogen that studies have shown to increase tumor cell proliferation and the transformation of healthy breast epithelial cells into cancer cells.[5],[6],[7]

Passive smoke is the involuntary exposure to somebody else’s tobacco smoke. Passive smokers inhale secondhand smoke from the exhaled smoke of active smokers, and also from the smoke that emerges from smoldering tobacco.

What evidence links active and passive smoking to breast cancer?

Cigarette smoking causes more than 480,000 deaths each year in the United States alone.[8] Tobacco smoke contains chemicals that have been linked to breast and other cancers.[9]

The California Teachers Study, one of the largest studies to follow participants over time, found an increased risk of breast cancer among smokers. More specifically, the study revealed a heightened risk for those who began smoking during adolescence, those who had smoked for at least 5 years prior to their first full-term pregnancy, and those who were deemed long-term or heavy smokers.[10] This supported earlier studies that suggested that women who began smoking as adolescents had an increased risk of breast cancer.[11],[12],[13],[14],[15] A recent meta-analysis, however, did not find a relationship between initiation of smoking before a first-time pregnancy and breast cancer risk[16]. More research is needed to explore these inconsistent findings.

Multiple studies support increased risk of breast cancer as a result of number of cigarettes smoked, duration of smoking, and age of smoking initiation. Results from the Canadian National Breast Screening Study revealed that smoking for a long period of time and smoking many cigarettes per day were both associated with increased rates of breast cancer.[17] The Nurses’ Health Study and the Women’s Health Initiative Study both indicated similar results, suggesting longer duration of smoking, greater quantities of cigarettes smoked, and younger age when starting to smoke were all positively linked to higher incidence rates of breast cancer.[18],[19]

Researchers from the National Cancer Center in Japan reported an increased risk of breast cancer in pre-menopausal women for both active and passive smoking.[20] Research, however, has provided mixed data on the impact passive smoking has on breast cancer risk. The California Teachers Study, for example, revealed no apparent relationship with passive smoking and increased breast cancer risk,[21] while other studies found a positive association between regular exposure to passive smoke and breast cancer risk.[22],[23],[24] The Women’s Health Initiative found that passive smoke exposure lasting more than 10 years in childhood, 20 or more years for adults at home, and 10 years for adults at work was linked to increased risk of breast cancer.[25]

Who is most likely to be exposed to tobacco smoke?

Those exposed include tobacco smokers, whether they use cigarettes, pipes, or vaping devices, and non-smokers around them who inhale air polluted with tobacco smoke. Current evidence suggests that both active and secondhand exposure can increase breast cancer risk, even though women who are exposed to secondhand smoke receive a much lower dose of carcinogens than do active smokers.[26],[27]

The Women’s Health Study indicated that 88 percent of people who have never smoked were exposed to passive smoking in their lifetime,[28] so most people will be exposed to tobacco smoke during their lifetime.

Who is most vulnerable to the health effects?

Overall, research suggests earlier exposures to tobacco smoke are of greater concern.

  • Some studies indicate smoking before a first full-term pregnancy may increase the risk of a later diagnosis of breast cancer.[29],[30]
  • Smoking during adolescence has been found to be associated with increased breast cancer risk.[31],[32],[33],[34],[35]
  • Studies also suggest increased risk of breast cancer for pre-menopausal women.[36]
  • Individuals who have smoked for a long time or have smoked heavily seemed to have higher risks for breast cancer.[37]

What are the top tips to avoid exposure to tobacco smoke?

  • Stop smoking. Avoid cigarettes and other tobacco products.
  • Avoid secondhand smoke as much as possible.

[1]IARC: International Agency for Research on Cancer (1987):  http://www.inchem.org/documents/iarc/suppl7/benzene.html

[2] National Toxicology Program- U.S. Department of Health and Human Services (13th edition). Vinyl haldies. http://ntp.niehs.nih.gov/ntp/roc/content/profiles/benzene.pdf Retrieved June, 2016.

[3] National Toxicology Program- U.S. Department of Health and Human Services (13th edition). Vinyl haldies. http://ntp.niehs.nih.gov/ntp/roc/content/profiles/vinylhalides.pdf Retrieved June, 2016.

[4] Chen, Z., Liu, C., Chen, F., Li, S., Liang, Q., & Liu, L. (2006). Effects of tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) on the activation of ERK1/2 MAP kinases and the proliferation of human mammary epithelial cells. Environmental Toxicology and Pharmacology, 22(3), 283-291. doi:10.1016/j.etap.2006.04.001

[5] Mei, J., Hu, H., McEntee, M., Plummer (3rd), H., Song, P., & Wang, H. (2003). Transformation of non-cancerous human breast epithelial cell line MCF10A by the tobacco-specific carcinogen NNK. Breast Cancer Res Treat, 79, 95–105.

[6] Chen, Z., An, Y., Wang, Z., Zhang, B., & Liu, L. (2007). Tobacco-specific carcinogen 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanone (NNK) activating ERK1/2 MAP kinases and stimulating proliferation of human mammary epithelial cells. Chem Res Chin Univ, 23, 76–80

[7] Siriwardhana, N., Choudhary, S., & Wang, H. (2008). Precancerous model of human breast epithelial cells induced by NNK for prevention. Breast Cancer Res Treat, 109, 427–441.

[8] US Department of Health and Human Services. The health consequences of smoking—50 years of progress: a report of the Surgeon General. Atlanta, GA: US 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. 2014;17.

[9] OEHHA- Office of Environmental Health Hazard Assessment (2005): http://oehha.ca.gov/media/downloads/air/report/app32005.pdf Retrieved June, 2016.

[10] Reynolds, P., Hurley, S., Goldberg, D., Anton-Culver, H., Bernstein, L., Deapen, D., … Ziogas, A. (2004). Active smoking, household passive smoking, and breast cancer: Evidence from the California Teachers Study. J Natl Cancer Inst, 96, 29-37.

[11] Band PR, Le ND, Fang R, Deschamps M. Carcinogenic and endocrine disrupting effects of cigarette smoke and risk of breast cancer. The Lancet. 2002 Oct 5;360(9339):1044-9.

[12] Calle, E., Miracle-McMahill, H., Thun, M., & Heath, C. (1994). Cigarette smoking and risk of fatal breast cancer. Am J Epidemiol, 139, 1001–1007.

[13] Gram, I., Braaten, T., Terry, P., Sasco, A., Adami, H., Lund, E., & Weiderpass, E. (2005). Breast cancer among women who started smoking as teenagers. Cancer Epidemiol Biomarkers Prev, 14, 61–66.

[14] Johnson KC, Hu J, Mao Y (2000). Passive and active smoking and breast cancer risk in Canada, 1994-1997, The Canadian Cancer Registries Epidemiology Research Group. Cancer Causes Control, 11:211-221.

[15] Marcus, P., Newman, B., Millikan, R., Moorman, P., Baird, D., & Qagish, B. (2000). The associations of adolescent cigarette smoking, alcoholic beverage consumption, environmental tobacco smoke, and ionizing radiation with subsequent breast cancer risk. Cancer Causes Control, 11, 271–278.

[16] DeRoo, LA., Cummings, P., Mueller, BA., (2011). Smoking before the first term pregnancy and the risk of breast cancer: a meta-analysis. AM J Epidemiol, 174, 390-402.

[17] Cui, Y., Miller, A., & Rohan, T. (2006). Cigarette smoking and breast cancer risk: update of a prospective cohort study. Breast Cancer Res Treat, 100, 293.

[18] Xue, F., Willett, W. C., Rosner, B. A., Hankinson, S. E., & Michels, K. B. (2011). Cigarette smoking and the incidence of breast cancer. Arch Inter Med, 171(2), 125–133.

[19] Luo, J., Margolis, K.L., Wactawski-Wende, J. (2011). Association of active and passive smoking with risk of breast cancer among postmenopausal women: a prospective cohort study. BMJ 2011, 342.

[20] Hanaoka, T., Yamamoto, S., Sobue, T., Sasaki, S., & Tsugane, S. (2005). Active and passive smoking and breast cancer risk in middle-aged Japanese women. Int J Cancer, 114, 317–322.

[21] Reynolds, P., Hurley, S., Goldberg, D., Anton-Culver, H., Bernstein, L., Deapen, D., … Ziogas, A. (2004). Active smoking, household passive smoking, and breast cancer: Evidence from the California Teachers Study. J Natl Cancer Inst, 96, 29–37.

[22] Johnson KC, Hu J, Mao Y (2000). Passive and active smoking and breast cancer risk in Canada, 1994-1997, The Canadian Cancer Registries Epidemiology Research Group. Cancer Causes Control, 11:211-221.

[23] Johnson KC, Miller AB, Collishaw NE, Palmer JR, Hammond SK, Salmon AG, Cantor KP, Miller MD, Boyd NF, Millar J, Turcotte F. Active smoking and secondhand smoke increase breast cancer risk: the report of the Canadian Expert Panel on Tobacco Smoke and Breast Cancer Risk (2009). Tobacco control. 2010 Dec 8:tc-2010.

[24] Morabia, A., Bernstein, M., Heritier, S., & Khatchatrian, N. (1996). Relation of breast cancer to active and passive exposure to tobacco smoke. Am J Epidemiol, 143, 918–928.

[25] Luo, J., Margolis, K.L., Wactawski-Wende, J. (2011). Association of active and passive smoking with risk of breast cancer among postmenopausal women: a prospective cohort study. BMJ 2011, 342.

[26] Ambrosone, C., Freudenheim, J., Graham, S., Marshall, J., Vena, J., Brasure, J., … Shields, P. (1996). Cigarette smoking, N-acetyltransferase 2 polymorphisms, and breast cancer risk. J Am Med Assoc, 276, 1494–1501.

[27] Morabia, A., Bernstein, M., Heritier, S., & Khatchatrian, N. (1996). Relation of breast cancer to active and passive exposure to tobacco smoke. Am J Epidemiol, 143, 918–928.

[28] Luo, J., Margolis, K.L., Wactawski-Wende, J. (2011). Association of active and passive smoking with risk of breast cancer among postmenopausal women: a prospective cohort study. BMJ 2011, 342.

[29] Cui, Y., Miller, A., & Rohan, T. (2006). Cigarette smoking and breast cancer risk: update of a prospective cohort study. Breast Cancer Res Treat, 100, 293.

[30] Xue, F., Willett, W. C., Rosner, B. A., Hankinson, S. E., & Michels, K. B. (2011). Cigarette smoking and the incidence of breast cancer. Arch Inter Med, 171(2), 125–133.

[31] Band PR, Le ND, Fang R, Deschamps M. Carcinogenic and endocrine disrupting effects of cigarette smoke and risk of breast cancer. The Lancet. 2002 Oct 5;360(9339):1044-9.

[32] Calle, E., Miracle-McMahill, H., Thun, M., & Heath, C. (1994). Cigarette smoking and risk of fatal breast cancer. Am J Epidemiol, 139, 1001–1007.

[33] Gram, I., Braaten, T., Terry, P., Sasco, A., Adami, H., Lund, E., & Weiderpass, E. (2005). Breast cancer among women who started smoking as teenagers. Cancer Epidemiol Biomarkers Prev, 14, 61–66.

[34] Johnson KC, Hu J, Mao Y (2000). Passive and active smoking and breast cancer risk in Canada, 1994-1997, The Canadian Cancer Registries Epidemiology Research Group. Cancer Causes Control, 11:211-221.

[35] Marcus, P., Newman, B., Millikan, R., Moorman, P., Baird, D., & Qagish, B. (2000). The associations of adolescent cigarette smoking, alcoholic beverage consumption, environmental tobacco smoke, and ionizing radiation with subsequent breast cancer risk. Cancer Causes Control, 11, 271–278.

[36] Hanaoka, T., Yamamoto, S., Sobue, T., Sasaki, S., & Tsugane, S. (2005). Active and passive smoking and breast cancer risk in middle-aged Japanese women. Int J Cancer, 114, 317–322.

[37] Reynolds, P., Hurley, S., Goldberg, D., Anton-Culver, H., Bernstein, L., Deapen, D., … Ziogas, A. (2004). Active smoking, household passive smoking, and breast cancer: Evidence from the California Teachers Study. J Natl Cancer Inst, 96, 29–37.