The testing device, which contains 36 spots impregnated with chemically sensitive compounds, works by detecting patterns of volatile organic compounds in exhaled breath. These spots change colors when exposed to particular chemicals.

The goal of the study reported in the medical journal Thorax was to determine if various color patterns could be identified that accurately detect lung cancer.

The study included 49 patients with non-small-cell lung cancer, 73 with various other, non-malignant lung diseases, and 21 healthy "controls." Data from 70 percent of the subjects were used to identify a pattern that indicated the presence of lung cancer, which was then tested in the remaining 30 percent.

The predictive pattern identified by the researchers was able to spot 73 percent of cancers, while it incorrectly identified 28 percent of nonmalignant conditions as cancerous.

"Further work may clarify the nature of the distinct breath constituents," conclude Dr. Peter J. Mazzone, from The Cleveland Clinic, Ohio, and colleagues. "This would help to guide refinement of the sensor array and breath collection system to maximize the diagnostic accuracy of the test."