Some day your doctor may be able to detect the earliest signs of lung cancer just by asking you to exhale -- long before any symptoms develop.

Using DNA recovered from exhaled breath, researchers say they can detect precancerous genetic changes in cells that line the lungs.

Click here to read more: What Causes Lung Cancer?

This could allow doctors to potentially detect lung cancer at an early stage, when treatment may be most successful, says Simon Spivack, MD, MPH, a research physician in the Human Toxicology & Molecular Epidemiology Laboratory at the New York State Department of Health’s Wadsworth Center in Albany.

The approach is innovative and creative, says Louis Weiner, MD, chairman of medical oncology at Fox Chase Cancer Center in Philadelphia and moderator of a news conference at the annual meeting of the American Association for Cancer Research.

Researchers have already shown that genetic patterns in sputum can help determine if a person is at high risk of lung cancer, he explains.

The problem is that most people don’t produce sputum until they are already sick, Weiner says.

“By using exhaled breath, we may someday be able to identify lung cancer early, when we can limit damage."

Click here to read more: Understanding Lung Cancer Surgery

Cooled Breath Yields DNA

The work builds on previous research that showed that trace amounts of DNA could be extracted from cooled exhaled breath.

Using DNA captured from the breath of 33 people, the researchers showed that more tumor suppressor genes had been turned off in people with lung cancer than in those without cancer.

If there is something wrong with this gene, then it may not be able to protect against tumor growth. In fact, there were distinct genetic patterns in the never-smokers, former and current smokers, and those with lung cancer, Spivack tells WebMD.

The next step, he says, is to determine if the genetic patterns seen in DNA from the breath are the same as those in DNA from the lungs.

“People [with more tumor suppressor genes turned off] in their breath DNA may be at higher risk of lung cancer, although that remains to be proven,” Spivack says.

“Down the road, this could prove to be a real winner,” Weiner says. “Keep it on your radar screen.”

Click here to read more: Lung Cancer: Cutting-Edge Treatments

This article was reviewed by Louise Chang, MD.

SOURCES: Annual Meeting of the American Association for Cancer Research, Los Angeles, April 14-18, 2007. Simon Spivack, MD, MPH, research physician, Human Toxicology & Molecular Epidemiology Laboratory, New York State Department of Health’s Wadsworth Center, Albany. Louis Weiner, MD, chairman of medical oncology, Fox Chase Cancer Center, Philadelphia.