A very large research study published in the British Medical Journal found that cigarette smoking -- either past or present -- increases breast cancer risk in postmenopausal women. Exposure to second-hand smoke also increases breast cancer risk.
This study looked at information from the Women's Health Initiative Observational Study (WHI). The WHI aims to find links between lifestyle factors and health problems such as cancer. The researchers looked at the health histories of 79,990 women in the WHI between 1993 and 1998. The researchers were particularly interested in whether the women had ever smoked and for how long, when they started smoking, and their exposure to second-hand smoke. By 2009, after more than 10 years of follow-up, 3,520 women were diagnosed with breast cancer.
- 41,022 women never smoked; 1,692 of them (4.1%) were diagnosed with breast cancer
- 38,968 women smoked or had a history of smoking; 1,828 of them (4.7%) were diagnosed with breast cancer
Overall, women who smoked were 16% more likely to be diagnosed with breast cancer, compared to women who never smoked.
Women who smoked the longest had the greatest increase in breast cancer risk:
- women who smoked for 50 years or more were 35% more likely to be diagnosed compared to non-smokers
- women who started smoking before their first pregnancy were 21% more likely to be diagnosed compared to non-smokers
- women who started smoking before the age of 15 were 12% more likely to be diagnosed compared to non-smokers
More than 88% of the women who never smoked said they had been exposed to second-hand smoke. Women who had the longest lifetime exposure to second-hand smoke -- 10 or more years in childhood, 20 or more years as an adult, or 10 or more years at work -- were 32% more likely to be diagnosed with breast cancer compared to women who had less or no exposure to second-hand smoke.
Smoking is bad for your health, including your breast health. If you don't smoke, don't start. If you do smoke, use every resource you can find to help you quit. Knowing about all of the problems associated with smoking isn't always enough to make you quit. Smoking is a habit that's very hard to break. Fortunately, if you're serious about trying, you have lots of help:
- The American Lung Association offers a free online smoking cessation program. The American Cancer Society also has a quit smoking program. You can also call the ACS "quitline," at 1-800-ACS-2345, to get support and free advice on how to stop smoking from trained counselors.
- Medicines to help you quit can be taken as a pill, chewed as gum, or worn as a patch on the skin. Ask your doctor if one of these might be right for you.
- Acupuncture and meditation may help ease cigarette cravings.
- It's also easier if you have a friend who's also quitting or who can cheer you on when you're feeling you can't make it on your own.