BBC News: Sniffer dogs detect lung cancer

Sniffer dogs can be used to reliably detect lung cancer, according to researchers in Germany. Writing in the European Respiratory Journal, they found that trained dogs could detect a tumour in 71% of patients.

However, scientists do not know which chemical the dogs are detecting, which is what they say they need to know to develop a screening programme.

Cancer Research UK said that was still a "long way" off.

It was first suggested that dogs could "sniff out" cancer in 1989 and further studies have shown that dogs can detect some cancers such as those of the skin, bladder, bowel and breast.

Cancer Scent

It is thought that tumours produce "volatile chemicals" which a dog can detect. Researchers trained four dogs - two German shepherds, an Australian shepherd and a Labrador - to detect lung cancer.

Three groups of patients were tested: 110 healthy people, 60 with lung cancer and 50 with chronic obstructive pulmonary disease, a narrowing of the airways of the lungs.

They all breathed into a fleece filled tube, which absorbed any smells.

The dogs sniffed the tubes and sat down in front of those in which they detected lung cancer smells.

They were successful 71% of the time. The researchers showed the dogs were not getting confused by chemicals associated with chronic obstructive pulmonary disease or smoking.

Dr Thorsten Walles, the report's author from Schillerhoehe Hospital, said: "In the breath of patients with lung cancer, there are likely to be different chemicals to normal breath samples and the dogs' keen sense of smell can detect this difference at an early stage of the disease...

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