Cancer-smelling canines

Man's best friend could also be a lifesaver in the fight against cancer as scientists claim dogs can be used to detect bladder cancer by smelling urine.

There is already anecdotal evidence of dogs alerting their unsuspecting owners of skin cancer by persistently sniffing suspicious moles which were later diagnosed as malignant. Now, in research published in the British Medical Journal, scientists have shown dogs can identify bladder cancer by detecting chemicals in urine emitted by cancerous cells. "Dogs can be trained to detect some odour characteristics for bladder cancer," Dr Carolyn Willis, of Amersham Hospital in Buckingham in Central England, said. Cancer cells are thought to give off organic compounds with distinctive odours that dogs can detect even in very small quantities. Willis and her colleagues trained six dogs of varying breeds and ages to identify urine samples from 36 bladder cancer patients among 108 healthy volunteers. Each dog did nine tests which involved selecting the urine from a cancer patient from six other samples by lying down next to it. The dogs had an average success rate of 41%, which Willis said is significant by it would have been 14% by chance alone. During the training phase of the study, the dogs consistently identified a urine sample from a healthy control patient as cancerous. Further tests confirmed the volunteer did in fact have the disease. Willis believes dogs could play an important role in helping scientists identify the compounds emitted by cancerous cells, which could then be used to develop better tests.