U.S. researchers have developed a breath test that detects lung cancer. Researchers say the test is more sensitive than high-tech imaging, especially for distinguishing benign tumors from cancerous ones.
When an X-ray scan of a patient's lungs reveals a nodule or tiny mass, the challenge for doctors is determining whether the growth is benign, or a sign of early stage cancer. Investigators say the breath analysis could help when used in conjunction with PET scans or other imaging modalities.
Researchers conducted a trial involving 107 patients with lung cancer, 40 people with benign lung nodules, and seven individuals whose cancer had spread to other parts of their body. The results were compared to a group of 88 healthy individuals.
The breath analysis was almost as sensitive as high-tech imaging at identifying patients with lung cancer, and it was twice as accurate at distinguishing benign lung disease, dramatically reducing the rate of so-called “false positives.”
Michael Bousrama is an associate professor at the University of Louisville medical school and the study’s lead author. He says lung spots are often detected on an X-ray or CT (computed tomography) scan when a patient goes to the doctor complaining of shortness of breath or chest pain.
“In this day and age what you do is you do a biopsy; either you stick a needle through the skin and into the lung, into the mass, or you do a bronchoscopy; or you might get a PET scan to determine whether or not it’s more or less likely to be cancer. All of those things are expensive and the CT-guided biopsy and the bronchoscopy are invasive procedures. They have complications and pain associated with them. So the concept of being able to analyze somebody’s breath to help determine whether a given pulmonary nodule is cancer or not could be very appealing," said Bousrama.
Bousrama says the breath test, which can be done in the doctor’s office, has the potential to quickly put a patient’s mind at ease in determining that a growth is benign.
The test is designed to measure levels of four specific substances called carbonyl compounds, which are found in the breath of people with malignant tumors. The majority of patients in the study with benign nodules had at most only one elevated carbonyl compound compared to people with stage IV lung cancer. They had three or four elevated cancer markers.
Bousrama envisions using the breath analysis to confirm an initial diagnosis of lung cancer using high-tech imaging. He says the test won’t be available for a number of years.
Michael Bousrama described the breath analysis test at a meeting of the American Association for Thoracic Surgery in Toronto, Canada.