CLEVELAND — November is Lung Cancer Awareness month. The disease is the leading cause of cancer death around the world, and according to the American Lung Association, nearly a quarter of a million Americans may be diagnosed this year and nearly 50,000 of them had never smoked.
Routine screenings are still limited to certain groups at risk, but Cleveland Clinic is researching whether a blood test can find cases earlier.
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While smoking is the main cause of most lung cancers, it's not the only cause.
"Family history — parents, brothers and sisters had lung cancer, your risk is a little bit higher," Cleveland Clinic pulmonologist and researcher Dr. Peter Mazzone said. "Other exposures [include] if you handled and worked with asbestos as part of your career, if you're exposed to radon gases in your home."
Currently, low dose radiation CT scans are used to find lung cancer, but mainly for those who fit certain risk criteria — those age 50-80 with a pack-a-day-for-20-years smoking history who either still smoke or quit within the last 15 years.
"This has been standard of care for a well-defined high-risk group for the last eight years or so," Mazzone explained. "I wish more people who were eligible were coming to get those screening scans done, because we'd be able to save a lot more lives."
Only about 10% of those eligible get screened. That's why Mazzone is researching a test that could detect lung cancer DNA in the blood.
"Technologies nowadays can detect that little bit of DNA in the blood compared to all the DNA from normal cells and notice differences in it," he said. "It may be differences in the size — we call fragment length — of that DNA, it may be differences in the genes or in how those genes get signaled. Tests that can identify those really low levels of DNA in the blood may be able to tell us that somebody has an early-stage lung cancer, prompting them to go get a CAT scan of their chest and find that cancer before they get sick with it."
Mazzone and his team studied 813 adult patients aged 50-80 years who smoked greater than or equal to 20 years — about 188 patients with a confirmed lung cancer diagnosis and 625 without. The blood test was able to detect early-stage lung cancer with a sensitivity of about 91-92%, meaning it correctly identified cancer in these cases 91-92% of the time.
These preliminary findings show the potential of this blood test to detect early-stage lung cancer with high sensitivity, which could improve implementation and effectiveness of lung cancer screening. Mazzone thinks we may not have to wait too long for the test to become available.
"I wouldn't be surprised if a lung cancer screening blood test was available within the next year or two," he told 3News, "and there will be more to come with even more and more accurate tests available over the next five years."