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Lung Cancer

  • Posted: 07/26/2007

Risk Factors

Doctors cannot always explain why one person develops lung cancer and another does not. However, we do know that a person with certain risk factors may be more likely than others to develop lung cancer. A risk factor is something that may increase the chance of developing a disease.

Studies have found the following risk factors for lung cancer:

  • Tobacco smoke: Tobacco smoke causes most cases of lung cancer. It's by far the most important risk factor for lung cancer. Harmful substances in smoke damage lung cells. That's why smoking cigarettes, pipes, or cigars can cause lung cancer and why secondhand smoke can cause lung cancer in nonsmokers. The more a person is exposed to smoke, the greater the risk of lung cancer. For more information, see the NCI fact sheets Harms of Smoking and Health Benefits of Quitting 1 and Secondhand Smoke and Cancer 2.
  • Radon: Radon is a radioactive gas that you cannot see, smell, or taste. It forms in soil and rocks. People who work in mines may be exposed to radon. In some parts of the country, radon is found in houses. Radon damages lung cells, and people exposed to radon are at increased risk of lung cancer. The risk of lung cancer from radon is even higher for smokers. For more information, see the NCI fact sheet Radon and Cancer 3.
  • Asbestos and other substances: People who have certain jobs (such as those who work in the construction and chemical industries) have an increased risk of lung cancer. Exposure to asbestos, arsenic, chromium, nickel, soot, tar, and other substances can cause lung cancer. The risk is highest for those with years of exposure. The risk of lung cancer from these substances is even higher for smokers.
  • Air pollution: Air pollution may slightly increase the risk of lung cancer. The risk from air pollution is higher for smokers.
  • Family history of lung cancer: People with a father, mother, brother, or sister who had lung cancer may be at slightly increased risk of the disease, even if they don't smoke.
  • Personal history of lung cancer: People who have had lung cancer are at increased risk of developing a second lung tumor.
  • Age over 65: Most people are older than 65 years when diagnosed with lung cancer.

Researchers have studied other possible risk factors. For example, having certain lung diseases (such as tuberculosis or bronchitis) for many years may increase the risk of lung cancer. It's not yet clear whether having certain lung diseases is a risk factor for lung cancer.

People who think they may be at risk for developing lung cancer should talk to their doctor. The doctor may be able to suggest ways to reduce their risk and can plan an appropriate schedule for checkups. For people who have been treated for lung cancer, it's important to have checkups after treatment. The lung tumor may come back after treatment, or another lung tumor may develop.

How To Quit Smoking

Quitting is important for anyone who smokes tobacco -- even people who have smoked for many years. For people who already have cancer, quitting may reduce the chance of getting another cancer. Quitting also can help cancer treatments work better.

There are many ways to get help:

  • Ask your doctor about medicine or nicotine replacement therapy, such as a patch, gum, lozenge, nasal spray, or inhaler. Your doctor can suggest a number of treatments that help people quit.
  • Ask your doctor to help you find local programs or trained professionals who help people stop using tobacco.
  • Call staff at NCI's Smoking Quitline (1-877-44U-QUIT) or instant message them through LiveHelp (http://www.cancer.gov/livehelp). They can tell you about:
    • ways to quit smoking
    • groups that help smokers who want to quit
    • NCI publications about quitting smoking
    • how to take part in a study of methods to help smokers quit
  • Go online to Smokefree.gov (http://www.smokefree.gov), a Federal Government Web site. It offers a guide to quitting smoking and a list of other resources.


Glossary Terms

asbestos (as-BES-tus)
A group of minerals that take the form of tiny fibers. Asbestos has been used as insulation against heat and fire in buildings. Loose asbestos fibers breathed into the lungs can cause several serious diseases, including lung cancer and malignant mesothelioma (cancer found in the lining of the lungs, chest, or abdomen). Asbestos that is swallowed may cause cancer of the gastrointestinal tract.
bronchitis (bron-KY-tis)
Inflammation (swelling and reddening) of the bronchi.
radioactive (RAY-dee-oh-AK-tiv)
Giving off radiation.
risk factor (... FAK-ter)
Something that increases the chance of developing a disease. Some examples of risk factors for cancer are age, a family history of certain cancers, use of tobacco products, being exposed to radiation or certain chemicals, infection with certain viruses or bacteria, and certain genetic changes.
tuberculosis (too-BER-kyoo-LOH-sis)
A disease caused by a specific type of bacteria that spreads from one person to another through the air. Tuberculosis can affect many parts of the body, but most often affects the lungs. A person may not have symptoms of tuberculosis for years, but they may appear when the patient becomes ill with a serious condition like diabetes, AIDS, or cancer. Tuberculosis can usually be treated and cured with antibiotics. Also called TB.

Table of Links

1http://www.cancer.gov/cancertopics/factsheet/Tobacco/cessation
2http://www.cancer.gov/cancertopics/factsheet/Tobacco/ETS
3http://www.cancer.gov/cancertopics/factsheet/Risk/radon