Lung Cancer Screening

What is Lung Cancer?

Lung cancer is a disease in which malignant (cancer) cells form in the tissues of the lung.

Lung cancers are usually grouped into two main types called small cell and non-small cell. These types of lung cancer grow differently and are treated differently. Non-small cell lung cancer is more common than small cell lung cancer, while small-cell lung cancer is fast growing, or more aggressive.

Facts and Figures

In Missouri, lung cancer is the most common type of non-skin cancer among both men and women.  It is the leading cause of cancer death, so catching it early is especially important.

Screening Recommendation

The United States Preventive Services Task Force recommends yearly lung cancer screening with low-dose computed tomography for people who are 50 to 80 years old; do not have signs or symptoms of lung cancer; have not had lung cancer before; currently smoke or have smoked in the last 15 years; or are current or former heavy smokers.

Heavy smoking means having a smoking history of 20 pack years or more. A pack year is smoking an average of one pack of cigarettes per day for one year. For example, a person could have a 20 pack-year history by smoking one pack a day for 20 years or two packs a day for 10 years.

Lung cancer screening is recommended only for adults who have no symptoms but who are at high risk for developing the disease because of smoking history and age.

Those thinking about getting screened should talk to a doctor, who can give a referral to a high quality screening facility.

Screening Test

The only recommended screening test for lung cancer is low-dose computed tomography, also called a low-dose CT scan or LDCT. In this test, an x-ray machine scans the body and uses low doses of radiation to make detailed pictures of the lungs.

Lung Cancer Prevention

Lung cancer prevention involves avoiding risk factors that are known to increase the chance of developing lung cancer, as well as implementing actions that have been found to decrease lung cancer risk.  Some risk factors cannot be controlled, such as age, gender, race or family history.  However, there are actions that can be taken to reduce lung cancer risk.

Avoid Tobacco

The best way to prevent lung cancer is to not smoke.

Tobacco smoking is the most important risk factor for lung cancer. Cigarette, cigar, and pipe smoking all increase the risk of lung cancer. Tobacco smoking causes about 9 out of 10 cases of lung cancer in men and about 8 out of 10 cases of lung cancer in women.  Studies have shown that smoking low tar or nicotine cigarettes does not lower the risk of lung cancer.

Studies also show that the risk of lung cancer from smoking cigarettes increases with the number of cigarettes smoked per day and the number of years smoked. People who smoke have about 20 times the risk of lung cancer compared to those who do not smoke.

Smokers can decrease the risk of lung cancer by quitting. In smokers who have been treated for lung cancer, quitting smoking lowers the risk of new lung cancers. Counseling, the use of nicotine replacement products, and antidepressant therapy have helped smokers quit for good.
In a person who has quit smoking, the chance of preventing lung cancer depends on how many years and how much the person smoked and the length of time since quitting. After a person has quit smoking for 10 years, the risk of lung cancer decreases by 30 to 50%.

Lung Cancer Prevention Resources

The Missouri Tobacco Quitline can help current smokers quit by assigning registered participants with a trained quit coach to make a plan to stop smoking.  The Quitline can be accessed by dialing 1-800-QUIT-NOW or at

Limit Exposure to Secondhand Smoke

Being exposed to secondhand tobacco smoke is also a risk factor for lung cancer. Secondhand smoke is exhaled by smokers and comes from the burning end of a cigarette or other tobacco product. People who inhale secondhand smoke are exposed to the same cancer-causing agents as smokers, although in smaller amounts. Inhaling secondhand smoke is called involuntary or passive smoking.

Lower Radon Exposure

Radon is a radioactive gas that comes from the breakdown of uranium in rocks and soil. It seeps up through the ground, and leaks into the air or water supply. Radon can enter homes through cracks in floors, walls, or the foundation, and levels of radon can build up over time.

Studies show that high levels of radon gas inside the home or workplace increase the number of new cases of lung cancer and the number of deaths caused by lung cancer. The risk of lung cancer is higher in smokers exposed to radon than in nonsmokers who are exposed to it.  About 26% of deaths caused by lung cancer in people who have never smoked have been linked to being exposed to radon.

Lowering radon levels may reduce the risk of lung cancer, especially among cigarette smokers. High levels of radon in homes may be reduced by taking steps to prevent radon leakage, such as sealing basements.

For more information on radon risk, testing and prevention, visit the Missouri Department of Health and Senior Services at

Lower Exposure to Workplace Risk Factors

Studies show that being exposed to the following substances increases the risk of lung cancer:

  • asbestos;
  • arsenic;
  • chromium;
  • nickel;
  • beryllium;
  • cadmium; and
  • tar and soot.

These substances can cause lung cancer in people who are exposed to them in the workplace and have never smoked.  As the level of exposure to these substances increases, the risk of lung cancer also rises. The risk of lung cancer is even higher in people who are exposed and also smoke.  Limiting exposure to these substances and chemicals can reduce lung cancer risk.

Sources / Resources