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The biggest risk factor for lung cancer is cigarette smoking. Tobacco use accounts for approximately 80 percent of all lung cancers. The longer you have smoked and the more packs you have smoked, the greater your risk of developing cancer. Exposure to secondhand smoke can also increase the odds a person will develop cancer.

Other risk factors include exposure to high levels of radon, an odorless radioactive gas that’s released into the air when uranium, which is found in soil and rocks, breaks down. Radon is found inside every home, and levels can be high if your house was built on soil containing uranium.

Exposure to asbestos fibers, tar, soot, or gasoline is also associated with an increased risk of developing lung cancer. Lung scarring from certain types of pneumonia or a diagnosis of chronic obstructive pulmonary disease (COPD) or emphysema elevates your risk as well.

Perlmutter Cancer Center doctors follow lung cancer screening guidelines, which encourage annual screening in smokers 55 to 80 years old who have a 30-pack-year smoking history, which is equivalent to smoking 1 pack a day for 30 years. Screening can be beneficial even if you quit up to 15 years ago.

Some medical organizations also recommend screening in people who are 50 or older and have a 20-pack-year smoking history, especially if they have additional risk factors for lung cancer, such as COPD or emphysema.

Our pulmonologists and radiologists pioneered the use of low-dose CT scans for lung cancer screening in the 1990s. Based on their work, low-dose CT scans are now the preferred screening method for detecting lung cancer. Our doctors can discuss the benefits and limitations of this form of screening with you.

A low-dose CT scan uses X-rays and a computer to produce detailed, three-dimensional, cross-sectional images of the body. Studies have shown that these scans are more accurate than conventional X-rays in detecting early lung cancers. In addition, a low-dose CT scan has about one-fifth the radiation dose of a standard CT scan, which helps limit radiation exposure in people who need yearly scans.

Suspicious spots or lesions are seen frequently on screening CT scans, especially in people who smoke. However, most of these are not caused by cancer. They are usually scars, enlarged blood vessels, or tiny lymph nodes, which are small glands in the immune system that trap foreign invaders such as bacteria and viruses.

People with suspicious spots in their lungs may need additional CT scans every 6 to 12 months to confirm that the images on the scan don’t change over time. Growths that do change require more testing because they could be cancerous.

Even if the initial screening result is normal, our doctors usually recommend that people at high risk consider annual low-dose CT scans until age 80.

Screening with CT scans should be discontinued after a person hasn’t smoked for 15 years or develops another health problem that decreases his or her life expectancy or the ability to have curative lung surgery.

Perlmutter Cancer Center researchers are part of the National Cancer Institute’s Early Detection Research Network. This is a group of scientists who are working to discover biomarkers, which are measurable substances, structures, or processes in the body that can signal the presence of a disease.

Our researchers study biomarkers that may, either on their own or in combination, aid in the diagnosis of lung cancer and could help streamline diagnosis. This includes whether biomarkers in blood and sputum could help doctors diagnose lung cancer earlier.

The hope is that the combination of a biomarker test and a CT scan could definitively diagnose or show that a particular spot or lesion is highly unlikely to be non-small cell lung cancer.

Your Perlmutter Cancer Center doctor can provide more information about participating in this research.