Cautious welcome for lung cancer 'breath test'

In collaboration with the Press Association

News of a prototype breath test that could one day be used to detect lung cancer when the disease is at its most treatable has been cautiously welcomed by Cancer Research UK.

The device, which is inexpensive to produce and is around the size of a coin, is not yet reliable enough for clinical use, however, achieving a 75 per cent accuracy rate in trials.

Researchers from the Cleveland Clinic in the US and private medical firm ChemSensing said that they hoped to be able to improve these results through further testing.

One of the reasons that lung cancer can be so resistant to treatment is that it is often not found until it has reached an advanced stage.

Ed Yong, senior health information officer at Cancer Research UK, commented: "This new method has only been tested in 143 people and must go through larger trials before it could ever be used routinely.

"The scientists would also need to show that it doesn't cause too many false alarms, which would lead to unnecessary worry in people who don?t actually have lung cancer.

"Although there is a long way still to go, the prospect of an easy, inexpensive test for this disease is exciting," he added.

Lung tumours emit volatile organic compounds (VOCs). Because they are in the lungs, the VOCs are likely to carried on the breath where they can be detected.

Previously this required expensive, specialist devices and trained staff, but using a device called a "colorimetric sensor array" the breath-test can detect cancer within minutes.

During trials, 143 patients were asked to breathe into the key-fob shaped device for 12 minutes.

The test correctly diagnosed 73 per cent of the patients with lung cancer and cleared 72 per cent of the non-lung cancer patients. Ed Yong added: "It's worth remembering however, that most lung cancers are preventable, with nine in ten cases caused by smoking. Quitting smoking is the best present you can give yourself."

The study is published in the journal Thorax.