Lung Cancer: Risk Factors

According to the National Cancer Institute, 221,200 new cases of lung cancer (non-small cell and small cell combined) were identified in the United States, in 2015.

Lung cancer is the leading cause of cancer deaths for both men and women, generally affecting older people. An estimated two out of three patients are 65 or older, when diagnosed. Fewer than two percent of all cases occur in people who are younger than 45.

A man’s chance of developing lung cancer in his lifetime is about one in 13; a woman’s one in 16. (These numbers include both smokers and non-smokers.) While the incidence of lung cancer is greater in men than in women, women appear to be catching up. Women also tend to be slightly younger, by about two years, at the age of diagnosis.

While there are certain known risk factors for lung cancer, many individuals who fall into the categories below will not get lung cancer.

  • Smoking: Tobacco use, and even second-hand smoke, can increase a patient’s risk of developing lung cancer. Cigarette smoking has been linked to roughly 90 percent of lung cancers. Those who smoke are 15 to 30 times more likely to get lung cancer than non-smokers. The longer an individual smokes, the more the risk of lung cancer increases. Quitting reduces that risk, but not to the level of those who have never smoked.
  • Marijuana use: Because this substance is primarily illegal, it may contain pesticides, in addition to having a higher level of tar than most cigarettes.
  • Race: Black males are about 20 percent more likely to develop lung cancer than white males.
  • Exposure to radon: Radon is a colorless, odorless, tasteless gas found naturally in the environment and is toxic because of its radioactivity. Radon gas can accumulate in buildings, especially in confined areas like attics and basements, and can also be found in some spring waters and hot springs.
  • Workplaceexposure to carcinogens (cancer-causing substances): These include radioactive ores, arsenic, asbestos, chromium and nickel, vinyl chloride, coal products. mustard gas and chloromethyl ethers.
  • Talcum powderused in industrial processes: No increased risk of lung cancer has been found from the use of cosmetic talcum powder, yet some studies of talc miners and millers suggest a higher risk of lung cancer associated with exposure to industrial grade talc.
  • A family member with lung cancer: If a parent, sibling or child has been diagnosed with lung cancer, an individual’s risk for developing lung cancer may increase.
  • Excessive use of alcohol: More than one drink a day for women, or two drinks a day for men—may increase risk of lung cancer.
  • Other smoking-related diseases: A diagnosis of emphysema or COPD (chronic obstructive pulmonary disease) may also increase lung cancer risk.
  • Genetics: Exposure to cigarette smoke, radon gas or asbestos may cause a mutation in the body’s genetic material or DNA, setting the stage for other cellular changes that lead to lung cancer, and may even increase its likelihood of spreading.