Lung Cancer Risk Factors

Many factors increase a person’s risk for lung cancer. These include:

Cigarette Smoking

  • Cigarette smoking is the primary risk factor associated with lung cancer. Tobacco smoke contains over 3000 different chemicals and more than 40 of them are potential carcinogens.
  • The risk for developing lung cancer is related to the number of cigarettes smoked per day and the total number of years of smoking.
  • If a person stops smoking, the risk of lung cancer decreases significantly after 5 years. After 15 years, the risk of developing lung cancer returns close to the risk level of non-smokers.


Passive Smoking

  • Passive smoke is referred to as environmental tobacco smoke (ETS) or secondhand smoke. It is the involuntary exposure of nonsmokers to tobacco smoke.
  • ETS causes 20% of lung cancers in nonsmokers and accounts for 3,000 cases per year.


Other Environmental and Occupational Factors

  • Exposure to cancer-causing agents (including radon, asbestos, arsenic, vinyl chloride, nickel chromates, coal products, mustard gas and chloromethyl ethers)
  • Radiation exposure from occupational, medical and environmental sources
  • Exposure to air pollution
  • A personal or family history of lung cancer
  • Lung scarring which results from some types of pneumonia and tuberculosis.
  • Age over 55

Persons at higher risk should contact their physician to see if screening, such as annual chest x-rays, may be appropriate.