Font Size

Non-Small-Cell Lung Cancer (cont.)

Non–Small-Cell Lung Cancer Causes

Tobacco smoking

  • Tobacco smoking is the cause of lung cancer in as many as 90% of cases.

  • A person who smokes is 13.3 times as likely to develop lung cancer as is a person who has never smoked. The risk also varies with the number of cigarettes smoked per day; people who smoke more than 20 cigarettes per day have a much greater risk of developing lung cancer than do those who smoke fewer than 20 cigarettes per day.

  • Once a person quits smoking, the risk of lung cancer increases for the first 2 years and then gradually decreases, but the risk never returns to the same level as that of a person who has never smoked.

  • Not all people who smoke develop lung cancer, and not all people with lung cancer smoke. Clearly, other factors, including genetic predisposition, also play a role.
Passive smoking (secondhand smoke)
  • As many as 15% of lung cancer cases involving nonsmokers may be caused by secondhand smoke.

  • The Environmental Protection Agency has recognized passive smoking as a potential cause of cancer.
  • Asbestos exposure has been linked to lung cancer and other lung diseases.

  • The silicate type of asbestos fiber is an important carcinogen.

  • Asbestos exposure increases the risk of lung cancer by as much as 5 times.

  • People who both smoke and have been exposed to asbestos are at an especially high risk of developing lung cancer.
  • Radon is a gas produced as a result of uranium decay. Radon exposure is a risk factor for lung cancer in uranium miners.

  • Radon exposure is believed to account for about 2-3% of lung cancers each year.

  • Household exposure to radon has never been clearly shown to cause lung cancer.
Other environmental agents
Exposures to the following agents account, at least partly, for some cases of lung cancer: 

Medical Author:
Medical Editor:
Medical Editor:
Medical Editor:

Must Read Articles Related to Non-Small-Cell Lung Cancer

Small-Cell Lung Cancer
Small-Cell Lung Cancer When cells of the lung start growing rapidly in an uncontrolled manner, the condition is called lung cancer. Lung cancer can affect any part of the lung. Lung c...learn more >>
Lung Cancer Medications
Understanding Lung Cancer Medications Medical therapy options for lung cancer include surgery, radiation, and/or chemotherapy. These treatments help decrease tumor growth and size. When tumor growth...learn more >>

Read What Your Physician is Reading on Medscape

Lung Cancer, Non-Small Cell »

Worldwide, bronchogenic carcinoma is the most common cause of cancer death in both men and in women.

Read More on Medscape Reference »

Medical Dictionary