Who Should Be Screened for Lung Cancer?

Lung cancer is the second most common type of cancer in the United States, killing more people each year than breast, colon, and prostate cancers combined. The earlier it’s diagnosed, the better the outcome. Inga Lennes, MD, MPH, MBA, 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? 

Lung cancer screening guidelines were updated in March, 2021 to include a wider range of ages and smoking history. “Research showed that we could identify more lung cancers if the age range was extended and the smoking history lowered,” says Dr. Lennes. “Black patients tend to get lung cancer earlier and with less of a smoking history. One point of making that change was to reduce disparities in lung cancer screening.”

Lung cancer screening is now recommended for patients who:

• Are 50 to 80 years old
• Currently smoke or have quit smoking within the last 15 years
• Have a 20-pack-year smoking history

Pack years measure how much and how often someone has smoked. 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. “If you have smoked, you should definitely get screened, but there are some things we have yet to discover that will tell us more about why patients who have never smoked get lung cancer,” says Dr. Lennes.

Known risk factors include:

• Smoking
• Exposure to second-hand smoke
• Exposure to airborne pollutants like asbestos
• Exposure to radon
• Family history
• Prior history of radiation

“If you have a strong family history of lung cancer, you should discuss it with your doctor to talk through the warning signs for lung cancer,” Dr. Lennes says.

What are the symptoms of lung cancer?

“Unfortunately, half or more lung cancers are diagnosed at advanced stages,” Dr. Lennes. “Patients with a history of smoking should be screened as soon as they’re eligible.”

Other 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. 

“To examine the lungs, we need less radiation energy than we do to see other structures in the body,” explains Dr. Lennes. “CT scans are very safe, but it’s great to minimize radiation exposure wherever we can.” 

A radiologist reads the CT scan and gives the scan a risk category level, based on the patient’s medical history and if the scans show any nodules. Nodules are small clumps of cells in the lungs that are mostly benign, but can 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?

“There are lots of reasons why you can have a nodule that isn’t cancer,” Dr. Lennes 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

“My biggest message is the overwhelming majority of nodules are not cancer, and the most important information we need to know about nodules is how they change over time. That’s why screening exams are so important. The best thing that patients can do to reduce their risk of getting lung cancer is to stop smoking,” says Dr. Lennes 

How will lung cancer screening change in the future?

Given that many cases of lung cancer occur in patients who don’t smoke, researchers are trying to find new screening methods. “There’s a lot of research on what we call biomarkers for disease. These might be compounds or chemicals found in our breath, blood, or urine,” Dr. Lennes says. “In the future, these could be paired with a CT scan to help diagnose cancer at earlier stages.”