A study found that breast cancer risk increased the most in postmenopausal women with heavy exposure to second-hand smoke as adults. Overall, exposure to second-hand smoke seemed to have little effect on breast cancer risk.
Doctors suspect that smoking and breast cancer risk are linked, but research results have been mixed. A large study on smoking and breast cancer risk reported in April 2009 found that both smoking and exposure to second-hand smoke raise breast cancer risk.
This study looked at the history of second-hand smoke exposure for 57,523 women who never smoked. Over 10 years, 1,754 of the women were diagnosed with breast cancer. Overall, there was a very small increase in breast cancer risk associated with second-hand smoke exposure. The increase in risk wasn't statistically significant, which means that it could have been due to chance and not because of second-hand smoke exposure. The strongest link between breast cancer risk and second-hand smoke exposure was in postmenopausal women with very heavy second-hand smoke exposure after age 20.
Smoking and second-hand smoke exposure can affect your health and increase your risk of several cancers, including breast cancer. If you don't smoke, don't start. If you or someone close to you does smoke, find a program or system for help quitting. Quitting may be tough, but it's definitely worth it. The American Lung Association offers a free online smoking cessation program. Local chapters of the American Cancer Society offer the Fresh Start program to help people quit smoking. You also can call the ACS "Quitline" at 1-800-ACS-2345 to get support and free advice on how to stop smoking from trained counselors.