May 14, 2014
News Review From Harvard Medical School -- U.S. Women Understate Lung Cancer Risk
Few American women realize that lung cancer is more likely to kill them than any other type of cancer, a new survey shows. Asked to pick the top killer of women from a list of cancers, 51% picked breast cancer. Only 22% picked lung cancer. The American Lung Association (ALA) did the survey. It included 1,000 women. About half of them said they were not concerned about lung cancer because they didn't smoke. Among lifelong nonsmokers, two-thirds were not concerned. But about 10% of lung cancer cases occur among those who have never smoked. And 20% of women who die of lung cancer are nonsmokers. Other causes of lung cancer include long-term exposure to radon, asbestos or secondhand smoke. If just the lung cancers not related to smoking were counted separately, they would still rank among the top 10 U.S. cancers, an ALA official told HealthDay News. Early screening for lung cancer is recommended only for long-term, heavy smokers ages 55 through 80. HealthDay wrote about the study May 13.
By Howard LeWine, M.D.
Harvard Medical School
What Is the Doctor's Reaction?
Lung cancer kills almost twice as many American women each year as breast cancer. But most women don't know it. That's because women constantly hear about breast cancer. They hear about it through fund-raising events and public promotions, such as urging women to get mammograms.
Lung cancer should be a special concern for women. Women have never smoked in the same numbers as men. Yet they account for nearly half the new cases. And although lung cancer deaths have dropped steadily in men since 1990, they continued to rise in women for the next 15 years. The reason: Women continued to smoke in the 1960s and 1970s, when men were starting to quit.
What worries many experts is that smoking increased in women even after its dangers became known. One reason is that many women believe smoking helps them control their weight. Another reason is that women have a harder time quitting than men do. And too many teens, girls as well as boys, are still taking up the smoking habit.
Smoking is by far the most common cause of lung cancer. Even today, it accounts for 80% of lung cancer deaths in women. But 20% of the women who die of lung cancer are nonsmokers. And among nonsmokers, women have a higher risk of developing lung cancer than men.
Scientists aren't sure why nonsmoking women have a higher risk than men. Some of the differences in risk may be explained by genes and hormones, possibly in combination.
Women are more likely than men to have certain genetic mutations linked with lung cancer risk. Some may be inherited. Others may result from greater sensitivity to tobacco smoke. So it's possible that secondhand smoke affects women more than men.
Estrogen may fuel cancer cell growth or interact with genes that boost the effects of secondhand smoke or other cancer-causing substances, such as asbestos and radon. Some studies suggest that early menopause, which causes a drop in estrogen levels, is linked to a lower risk of lung cancer. Women who take the estrogen blocker tamoxifen for treatment or prevention of breast cancer may also have a decreased chance of developing lung cancer.
What Changes Can I Make Now?
Of course, not smoking and limiting exposure to secondhand smoke is the best way to prevent lung cancer. Here are some other things you can do that may help:
- Change your diet. Although it's unproven, there is some evidence that eating lots of fruits and vegetables may reduce lung cancer risk.
- Install radon detectors in your home. If the alarm sounds, have trained professionals handle the problem. Radon exposure can increase the risk of lung cancer.
- Have your home inspected for asbestos, which also can cause lung cancer.
- Follow recommended safety procedures if you work in a job that may expose you to asbestos, vinyl chloride, uranium or coal products.
- Consider drinking green tea. It may reduce the risk of lung cancer in both smokers and nonsmokers.
Finding lung cancers when they are small improves the odds of a cure. Small cancers have the greatest chance of complete removal with surgery.
For both women and men, talk with your doctor about screening for lung cancer with a CT scan if:
- Your age is between 55 and 79.
- You currently smoke or you quit less than 15 years ago. (Your risk of lung cancer is much lower if you have already quit for 15 years or more.)
- Your total smoking equals 30 pack-years or more. Pack-years is the number of packs smoked per day times the number of years you smoked.
- Your health is good enough to withstand surgery and other treatment for lung cancer.
If you have symptoms that might be related to lung cancer, see your doctor right away. These include:
- A cough that won't go away, especially if you cough up any blood
- Wheezing or shortness of breath
- Chest pain
- Repeated bouts of pneumonia
- Unexplained weight loss or poor appetite (especially along with the symptoms above)
What Can I Expect Looking to the Future?
Efforts to help more smokers quit will continue. This will result in fewer lung cancer deaths caused by smoking.
However, the same can't be said for lung cancer in nonsmokers. The number of new cases and deaths has not changed. Prevention and treatment of lung cancer in nonsmokers remains a significant challenge that will require much more research.