U of L researchers developing a breath test for lung cancer

Lung cancer victims often don’t notice any symptoms before it’s too late, and Kentucky suffers from the highest rate of the disease — 3,500 deaths per year. Smoking, the leading cause of lung cancer, is the nation’s highest among Kentucky adults — 28.3 percent. Experts say approximately 85 percent of lung cancer cases or linked to smoking.

Now University of Louisville scientists are among those working on a test to detect the disease sooner, by analyzing exhaled breath.  The scientists use a specially designed microchip to test the breath of patients who have suspicious lung lesions, Laura Ungar reports for The Courier-Journal.

“Patients are very enthusiastic about it. The concept of having a painless method to tell if you’ve got cancer is really appealing,” Dr. Michael Bousamra told Ungar. Bousamra and his colleague Xiao-An Fu said the test might be available to the public in five years or less to ascertain who should undergo possibly dangerous biopsies.

“Instead of sending patients for invasive biopsy procedures when a suspicious lung mass is identified, our study suggests that exhaled breath could identify which patients may be directed for an immediate” sugical treatment, Bousamra said. While the current method of diagnosis, the PET scan, can cost more than $2,000, the breath analysis could cost $50 or less.

Lung cancer is the deadliest form of cancer; it kills 158,000 Americans every year, and the National Cancer Institute statistics show that the five-year survival rate for people whose lung cancer has spread to different organs is less than 4 percent — but is 54 percent when the cancer is only in the lung. “Dr. Norman Edelman, a Long Island pulmonologist who is a senior medical adviser for the American Lung Association, said he’s encouraged by the U of L study and a growing body of research looking at exhaled breath,” Ungar writes. “We’re delighted to see this type of research going on. It’s important,” Edelman told her. “The survival rate depends critically on early detection.”

Researchers hold breath test bag and microchip (U of L photo)

Researchers tested 150 patients with possible or diagnosed lung cancer and 85 healthy patients. Each patient exhaled a liter of air into a bag. A vacuum pulled the air across a specially coated silicone microchip, which analyzed specific compounds of the breath with a mass spectrometer, which measures the mass of a molecule to identify it. “Two of the four compounds they found in lung-cancer patients were previously known to be associated with the disease, but Fu discovered that the two others were also linked to lung cancer,” Ungar reports.

Bousamra said patients with high levels of all four compounds always had cancer. Three or four elevated compounds was predictive of the disease of 95 percent of patients with a mass, and two elevated compounds was predictive of the disease in two-thirds of patients. The absence of elevated compounds predicted a non-canercous mass 80 percent of the time. “High levels of the compounds among those with lung cancer returned to normal after doctors removed the mass,” Ungar writes.

Similar research is happening in other places as well. Edelman said this research will help doctors “make real strides against the disease,” but people need to remember that quitting tobacco is a key factor, too. “Half the people who are regular smokers will die of smoking-related disease,” he said. “The cure is very simple.” (Read more)