Who Should Be Screened for Lung Cancer?

Lung cancer is the leading cause of cancer death in the United States in both men and women. The earlier it’s diagnosed, the better the outcome. Lecia Sequist, MD, MPH, a medical oncologist at Mass General Cancer Center, discusses who should be screened for lung cancer and the role family history can play in the disease.

What is the screening criteria for lung cancer?

Not all lung cancer is related to tobacco smoking, but current screening for lung cancer is only proven in people with a tobacco use history. Lung cancer screening guidelines were updated in March, 2021 to allow more people to be eligible.

“Research shows that detecting lung cancer earlier helps improve outcomes. The new guidelines lower the minimum age and lower the required tobacco history, allowing more people access to be screened,” says Dr. Sequist. “Another goal of updating the guidelines was to help reduce disparities in lung cancer screening. Under the old guidelines, people of color and women were less likely to be able to be screened compared to white people and men.”

Lung cancer screening is now recommended for people who:

• Are 50 to 80 years old
• Currently smoke or have quit smoking within the last 15 years
• Have smoked at least 20-pack-years

Pack years are calculated by multiplying the number of years smoked times the number of packs smoked per day. Twenty pack years means they smoked the equivalent of a pack a day for 20 years, or they smoked 2 packs a day for 10 years, etc.

What are the risk factors for lung cancer?

Researchers are still uncovering the causes and risk factors of lung cancer. “One of the biggest risk factors is smoking, even if you used to smoke and don’t anymore,” says Dr. Sequist. “But people who have never smoked can still get lung cancer, and we’re studying why that is.”

Known risk factors include:

• Smoking
• Exposure to second-hand smoke
• Exposure to air pollution
• Exposure to asbestos
• Family history
• Exposure to fumes and chemicals in certain workplaces, like firefighters, military personnel, transportation or construction workers, farmers, and others
• Exposure to radon
• Prior history of radiation
• Chronic use of some immune suppressing medications

“If you have any of these risk factors, you should talk to your doctor and discuss the warning signs for lung cancer that you should watch out for,” Dr. Sequist says.

What are the symptoms of lung cancer?

“Lung cancer symptoms usually only appear when the disease is more advanced,” says Dr. Sequist. “Fortunately, the number of people who die from lung cancer is decreasing, thanks to advances in early detection and treatment.”

Lung cancer symptoms to watch out for include:

• A cough that lingers for weeks or months
• Coughing up blood
• Losing weight without trying

What is the screening process for lung cancer?

The recommended screening test for lung cancer is a low-dose CT (computerized tomography) scan. This scan uses a computer to combine images taken at different angles to create more detailed pictures of your body. There is no preparation before the scan, and no needles are placed into your body. The entire test takes under 5 minutes.

“If we detect lung cancer earlier with a CT scan, we can treat the disease more effectively and have higher chances of a cure,” explains Dr. Sequist. “CT scans for lung cancer screening are very safe and keep radiation exposure to a minimum.”

A radiologist interprets the CT scan and gives the scan a risk category level, based on whether they see any nodules. Nodules in the lungs are small spots, which are usually scars or inflammation, but could also be a sign of cancer. For high-risk scans, your health care provider may recommend you have a closer follow-up, get a more specialized scan, or undergo a biopsy. A biopsy is a minor procedure that removes a small piece of tissue or sample of cells from your body for further testing in a lab. For low-risk scans, your provider may recommend a follow-up scan at a later date.

Are lung nodules a sign of cancer?

“The majority of lung nodules are not cancer,” Dr. Sequist explains. Benign nodules can be caused by:

• A prior infection
• Acid reflux
• Inflammation
• Certain autoimmune conditions like rheumatoid arthritis
• Scarring from past smoking or pollution exposure

“Regular lung cancer screening is so important because those nodules can change over time, and that is often how we determine someone might have cancer. One of the best things you can do to reduce your risk of getting lung cancer is to quit smoking,” says Dr. Sequist.

How will lung cancer screening change in the future?

Given that many cases of lung cancer occur in patients who smoked only a small amount, quit many years ago, or never used tobacco, researchers are trying to find new screening methods that could apply to even more people.

“New advancements in genetic testing and artificial intelligence are moving us closer to providing truly personalized cancer screenings,” Dr. Sequist says. “In the near future, we may be able to diagnose cancer at even earlier stages.”