Newly published study results demonstrate an intriguing potential for the use of breath tests to identify and characterize lung cancer, according to researchers at the Cleveland Clinic.

Metabolomx, a diagnostic company focused on the detection of the metabolomics signature of cancer from exhaled breath, tested its first-generation colorimetric sensor array, reporting an accuracy exceeding 80 percent in lung cancer detection, which is comparable to CT scan performance.

Results also showed the sensor could identify the subtype of lung cancer, whether it be small cell, adenocarcinoma, or squamous cell, with near 90 percent accuracy.

"Our research shows that breath testing may help identify patients with lung cancer, as well as provide us with information that can help with treatment decisions, such as the type of lung cancer, its stage, and prognosis,” said lead researcher Dr. Peter Mazzone. “The accuracy of these non-invasive tests can be further augmented when combined with existing clinical predictors, such as health status and age."

The sensor detects the unique pattern of volatile organic compounds, or the metabolic biosignature, present in exhaled breath. For the study, breath samples were drawn from 229 individuals, 92 with biopsy-proven, untreated lung cancer and 137 either at a risk for developing lung cancer or with indeterminate lung nodules.

The results come as the National Cancer Institute calls for wider CT screening of high-risk patients. In June, NCI published data from the National Lung Screening Trial, which showed 20 percent reduction in lung cancer mortality with low-dose CT compared to chest X-ray.

"These results show that the first generation of our breath test technology compares well with CT scans,” said Paul Rhodes, PhD, Founder and CEO of Metabolomx. “Detection of the metabolomic signature of lung cancer in exhaled breath is non-invasive, rapid, and inexpensive, and will become a valuable adjunct to help assess an indeterminate CT, and may come to have a central role in early detection and differentiation of lung cancer, while lowering costs to the healthcare system."

Mazzone is quite familiar with colorimetric sensory arrays. In 2007, he led a study at the Cleveland Clinic on another sensor, this from a company called ChemSensing, whose system was first developed to identify and measure levels of potentially deadly gas exposures. The “proof of principle” study found that the sensor could distinguish between patients with lung cancer and healthy subjects, albeit not with the success seen in the Metabolomx trial.

In 2007, Mazzone noted, “I do not know if this type of device will ever develop into something clinically useful. But what we've seen holds out enough promise that we want to continue to pursue this line of study."

The article, "Exhaled Breath Analysis with a Colorimetric Sensor Array for the Identification and Characterization of Lung Cancer," is published in the current, online issue of the Journal of Thoracic Oncology, the official journal of the International Association for the Study of Lung Cancer.

Initial results from the study were presented at the American College of Chest Physicians conference in November 2010.