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Lung Cancer Screening

Can Lung Cancer Be Found Early?


In the United States, lung cancer is the second most common cancer in both men and women. It’s also the leading cause of death from cancer.

Lung cancer can be serious. However, some people with early stage lung cancer can be successfully treated. This is because tests and treatments for cancer are being studied and improved. If lung cancer is found at an earlier stage when it is small and before it has spread, people have a better chance of living longer.

Current and former smokers are at a higher risk of getting lung cancer as they get older. If they quit, smokers can lower their risk of getting and dying from lung cancer.

Usually symptoms of lung cancer don’t appear until the disease is already at an advanced, non-curable stage. Even if lung cancer does cause symptoms, many people may mistake them for other problems, such as an infection or long-term effects from smoking. This may delay the diagnosis.

Some lung cancers are found early by accident as a result of tests for other medical conditions. For example, lung cancer may be found by tests done for other reasons in people with heart disease, pneumonia, or other lung conditions. A small portion of these people do very well and may be cured of lung cancer.

Screening is the use of tests or exams to find a disease in people who don’t have symptoms. Regular chest x-rays have been studied for lung cancer screening, but they did not help most people live longer. In recent years, a test known as a low-dose CAT scan or CT scan (LDCT) has been studied in people at a higher risk of getting lung cancer. LDCT scans can help find abnormal areas in the lungs that may be cancer. Research has shown that using LDCT scans to screen people at higher risk of lung cancer saved more lives compared to chest x-rays. For higher risk people, getting yearly LDCT scans before symptoms start helps lower the risk of dying from lung cancer.

Guidelines for Lung Cancer Screening


Updated as of May 23, 2022.

The most recent version of the American Cancer Society (ACS) lung cancer screening guideline [from 2018] is being taken down while we review new scientific evidence to be included in the next update. While this important update is being completed, the ACS advises that health care providers, and people at increased risk for lung cancer, follow the recently updated recommendations for annual lung cancer screening from the US Preventive Services Task Force (USPSTF), the American Academy of Family Physicians (AAFP), or the American College of Chest Physicians.

These organizations recommend yearly lung cancer screening with LDCT scans for people who:

  • Are 50 to 80 years old and in fairly good health,

  • Currently smoke or have quit in the past 15 years,

  • Have at least a 20 pack-year smoking history. (This is the number of packs of cigarettes per day multiplied by the number of years smoked. For example, someone who smoked 2 packs a day for 10 years [2 x 10 = 20] has 20 pack-years of smoking, as does a person who smoked 1 pack a day for 20 years [1 x 20 = 20].)

In addition, it’s important that people who are going to be screened:

  • Receive counseling to quit smoking if they currently smoke,

  • Have been told by their doctor about the possible benefits, limits, and harms of screening with LDCT scans,

  • Can go to a center that has experience in lung cancer screening and treatment.

For Patients


The main benefit of screening is a lower chance of dying of lung cancer, which accounts for many deaths in current and former smokers. Still, it’s important to be aware that, like with any type of screening, not everyone who gets screened will benefit.


Screening with LDCT will not find all lung cancers, and not all of the cancers that are found will be found early. Even if a cancer is found by screening, you may still die from lung cancer. Also, LDCT often finds things that turn out not to be cancer, but have to be checked out with more tests to know what they are. You might need more CT scans, or even invasive tests such as a lung biopsy, in which a piece of lung tissue is removed with a needle or during surgery. These tests have risks of their own.

If you are at a higher risk, your doctor can explain your risk and how you fit into the ACS lung cancer screening guideline. Your doctor can also talk with you about what happens during screening and the best places to get the yearly screening test. Lung cancer screening is covered by Medicare and by many private health insurance plans. Your health care team can help you find out if your insurance will provide coverage. 

Screening should only be done at facilities that have the right type of CT scanner and that have a lot of experience in LDCT scans for lung cancer screening. The facility should also have a team of specialists that give patients the appropriate care and follow-up if there are abnormal results on the scans. You might not have the right kind of facility nearby, so you may need to travel some distance to be screened.

If you are at higher risk and should be screened, you should get a LDCT every year until you reach the age of 80, as long as you are still in good health.

If you smoke, you should get counseling about stopping. You should be told about your risk of lung cancer and referred to a smoking cessation program. Screening is not a good alternative to stopping smoking. 

What Does in "Fairly Good Health" Mean?

Screening is meant to find cancer in people who do not have symptoms of the disease. People who already have symptoms that might be caused by lung cancer may need tests such as CT scans to find the underlying cause, which in some cases may be cancer.


But this kind of testing is for diagnosis and is not the same as screening. Some of the possible symptoms of lung cancer that kept people out of the NLST were coughing up blood and weight loss without trying.

To get the most benefit from screening, patients need to be in good health. For example, they need to be able to have surgery and other treatments to try to cure lung cancer if it is found. Patients who need home oxygen therapy probably couldn’t withstand having part of a lung removed, and so are not candidates for screening. Patients with other serious medical problems that would shorten their lives or keep them from having surgery might not benefit enough from screening for it to be worth the risks, and so should also not be screened.

Metal implants in the chest (like pacemakers) or back (like rods in the spine) can interfere with x-rays and lead to poor quality CT images of the lungs. People with these types of implants were also kept out of the NLST, and so should not be screened with CT scans for lung cancer according to the ACS/ACCP/ASCO guidelines.

If Something Abnormal is Found during Screening

Sometimes screening tests will show something abnormal in the lungs or nearby areas that might be cancer. Most of these abnormal findings will turn out not to be cancer, but more CT scans or other tests will be needed to be sure. 

CT scans of the lungs can also sometimes show problems in other organs that just happen to be in the field of view of the scans. Your doctor will discuss any such findings with you if they are found.

For more information on lung cancer screening, please click to learn more.

Content provided by the American Cancer Society.

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