Understanding the Connection Between Smoking and Breast Cancer

The precise connection between smoking and breast cancer is still unclear, but there does appear to be some sort of link. Let's examine this interesting relationship more closely and explore what it means for you and your health.

Illustration by Laura Porter for Verywell Health

Cancer-Containing Chemicals in Cigarette Smoke

The link between smoking and cancers, in general, is undeniable. Cigarette smoke contains cancer-causing chemicals that are absorbed into your body and affect your present and future health. Here are just a few of the 3,000 chemicals in tobacco smoke that are related to cancer:

  • Tar – a sticky substance that is created as tobacco burns. Inhaling while smoking pulls tar into your lungs, where it accumulates over time and causes tissue destruction.
  • Nicotine – an extremely addictive drug that helps cancers grow
  • Nitrosamine – a carcinogenic compound that occurs in tobacco—it has been used in cosmetics, processed meats, pesticides, and latex products.

The Link Between Breast Cancer and Smoking

Chronic, heavy smoking is linked to a higher risk of breast cancer, according to the American Cancer Society. This risk may be highest in women who start smoking before having their first full-term pregnancy, according to a 2011 study in the Archives of Internal Medicine. This may be because breast development is completed during the third trimester of a woman's pregnancy. At this point, a woman's breast cells may be less vulnerable to the carcinogens of tobacco smoke.​

In addition, certain women may be more vulnerable to smoking's effects on the breast than other women, based on their genetic makeup. This means that having a certain gene or genes may put a woman more at risk of developing breast cancer when exposed to smoke.

The link between secondhand smoke and an increased risk of breast cancer is a bit more controversial—but scientific data suggest avoiding secondhand smoke is also wise.

It's interesting to note that smoking after menopause may slightly decrease a woman's risk of breast cancer, according to the 2011 study in Archives of Internal Medicine. The authors suggest that smoking potentially has a small anti-estrogen effect. This effect is too little to be noticed in premenopausal women who have higher estrogen levels, but more significant in postmenopausal women, who already have low estrogen levels.

What Should You Do? 

Stop smoking—easier said than done, but certainly possible. In addition to benefiting your breast health, stopping smoking will help protect you from a number of other cancers and also protect your heart.

Get help to quit smoking, and avoid breathing secondhand smoke.

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention (US); National Center for Chronic Disease Prevention and Health Promotion (US); Office on Smoking and Health (US). How Tobacco Smoke Causes Disease: The Biology and Behavioral Basis for Smoking-Attributable Disease: A Report of the Surgeon General. Atlanta (GA): Centers for Disease Control and Prevention (US); 5, Cancer.

  2. Hecht SS, Hoffmann D. Tobacco-specific nitrosamines, an important group of carcinogens in tobacco and tobacco smoke. Carcinogenesis. 1988;9(6):875-84. doi:10.1093/carcin/9.6.875

  3. Health Risks of Smoking Tobacco. American Cancer Society.

  4. Xue F, Willett WC, Rosner BA, Hankinson SE, Michels KB. Cigarette smoking and the incidence of breast cancerArch Intern Med. 2011;171(2):125–133. doi:10.1001/archinternmed.2010.503

  5. Betts KS. Secondhand suspicions: breast cancer and passive smokingEnviron Health Perspect. 2007;115(3):A136–A143. doi:10.1289/ehp.115-a136

  6. Kim AS, Ko HJ, Kwon JH, Lee JM. Exposure to Secondhand Smoke and Risk of Cancer in Never Smokers: A Meta-Analysis of Epidemiologic StudiesInt J Environ Res Public Health. 2018;15(9):1981. Published 2018 Sep 11. doi:10.3390/ijerph15091981

  7. Toll BA, Rojewski AM, Duncan LR, et al. "Quitting smoking will benefit your health": the evolution of clinician messaging to encourage tobacco cessationClin Cancer Res. 2014;20(2):301–309. doi:10.1158/1078-0432.CCR-13-2261

Additional Reading

By Pam Stephan
Pam Stephan is a breast cancer survivor.