ROME, Italy, May 8 -- Researchers at the University of Rome have developed an electronic nose they say can identify people with lung cancer simply by sniffing their breath, the New Scientist reported this week. They hope it could lead to the development of a simple breath test for the early detection of the disease.
"A variety of conditions can lead to specific compounds turning up in the breath," reported the New Scientist. "For example, aliphatic acids show up in the breath of people with liver cirrhosis, while di- and tri-methylamine are found in the breath of those with failing kidneys. Lung cancer patients exhale a cocktail of alkanes and benzene derivatives, though no one is yet sure why."
Electronic noses are already used for quality control in the food industry. Gas chromatography and mass spectrometry are typically used to analyse gas mixtures, but these techniques are too expensive and elaborate to provide a practical diagnostic test, the article said.
"The electronic nose uses an array of quartz crystal sensors, each coated with a slightly different metalloporphyrin that binds to a different range of volatile organic chemicals," the New Scientist reported. "The crystals' natural vibration frequency is related to their weight. This changes as molecules from the sample stick to their coated surfaces, so a complex gas sample such as human breath will create a unique profile of vibrations from an array of crystals."
The team will next attempt to increase the nose's sensitivity in order to detect tumors at a much earlier stage. Doctors currently use an invasive procedure to detect lung cancer, using a bronchoscope to look inside a patient's lungs and remove tissue for a biopsy.
Skeptics say a clinical study conducted by the Roman research team was too small to be reliable, and the method could never replace blood tests or scans for lung tumors, especially secondary tumors, which are harder to detect.
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