Follow your nose

摘要

HIPPOCRATES, the father of medicine, was known to have used smell as an aid to his work. Generations of doctors followed suit. Syphilis, for instance, is thought to have a characteristic odour; the smell of rotting apples suggests diabetes. Today, things are more sophisticated. All sorts of volatile organic compounds (gases, known as VOCS, that are given off by living organisms) have been identified, in laboratories, as markers of specific diseases from breast cancer to cholera. A paper reported on a "breathprint" for malaria earlier in the month. But despite all this knowledge, a "breathalyser for disease" has stubbornly failed to materialise. The barrier, as so often with new diagnostic tools, is not whether such things are technically possible, but whether they can be proven to work reliably and usefully when used by doctors. Owlstone Medical, based in Cambridge, thinks it has developed just such a gadget. Its breath analyser is the subject of several big trials. One, called Lucid, is recruiting 4,000 patients across Europe to develop a test for the early detection of lung cancer-a disease that is often diagnosed too late to treat. Another, in collaboration with the Warwickshire NHS Trust, is attempting the detection of early-stage colorectal cancer in 1,400 people (existing screening methods are successful only 9% of the time). Cancer Research UK, a charity, is evaluating the breathalyser for early detection of a laundry list of other cancers (specifically bladder, breast, head and neck, kidney, oesophageal, pancreatic, prostate and brain).