The dogs being trained to sniff out cancer The UK has one of the worst cancer survival rates in Europe, mainly due to widespread late diagnosis. A Milton […]

The UK has one of the worst cancer survival rates in Europe, mainly due to widespread late diagnosis.

A Milton Keynes charity is hoping to change all that, by training up dogs of all breeds to sniff out cancerous cells, potentially saving thousands of lives.

Medical Detection Dogs was founded in 2008, after a report – in collaboration with the Buckinghamshire NHS Trust – provided the first robust evidence that dogs could be trained to smell and identify cancer reliably.

The charity’s CEO Claire Guest had heard anecdotal stories for years of people expressing the belief that their pet dogs could smell cancer.

For her, the story started when a friend had a similar experience, and her dog warned her of a malignant melanoma on her calf.

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“These stories were reported in the medical journal, The Lancet, on two occasions,” she says. “And it got us thinking, ‘could we actually train dogs to identify the odour of cancer?'”

Life-saving warnings

The charity works with two different kinds of dogs.

Bio-Detection dogs are trained to find the odour of diseases, such as cancer, in samples such as urine, breath and swabs.

Medical Alert Assistant Dogs specialise in detecting minute changes in an individual’s personal odour, triggered by their disease, and alert them to an impending medical event. These dogs live and work with their owners, in the same way a guide dog would.

Guest has her own story to share.

While she was working on research into dogs sniffing out bladder cancer, her pet dog Daisy began acting very strangely around her, and was consistently nudging her in the chest.

This pushed Guest to go and see her GP, and she was subsequently diagnosed with a deep-seated breast cancer.

“If it hadn’t been for Daisy, it would have taken years to find the lump and the prognosis could have been very poor,” she says.

Daisy was awarded the Blue Cross Medal for her pioneering work in the field of cancer detection.

She has sniffed over 6,500 samples and detected over 550 cases of cancer.

How does it work?

“A cancer alert dog is not trained to go and identify cancer on the actual person themselves,” explains Guest.

While humans have five million sensory receptors, dogs have around 300 million. It is estimated that the percentage of a dog’s brain devoted to analysing odour is 40 times larger than that of a human.

“A cancer alert dog does not go and sit beside someone who has cancer. What these dogs are trained to do is to recognise the odour signature – this is the volatile pattern or smell that cancer cells give off in samples.

“So the dogs are trained to recognise and screen samples of either breath or urine.”

There are two ways, Guest claims, in which dogs could make a huge difference in the way that cancer is diagnosed in the future.

“Firstly, if a machine could be designed that mimics the dog’s nose, this means that it could change the way that cancer is screened,” she says.

“Using a nano sensor that would look for the same volatile patterns the dogs use would mean that there was cheap, non-invasive, reliable ways of diagnosing cancer early and therefore saving thousands of lives.

“And this isn’t science fiction. Since 2004 there have already been three electronic nose systems designed, stemming from the work of the dogs, which has indicated that this is a true possibility.”

Second line screening

In the shorter term, these dogs are providing second line screening for cancers that are difficult to identify.

Early diagnosis of prostate cancer is one of the most effective ways of tackling the disease, but the current way of screening it has a 75% false positive rate, often resulting in unnecessary biopsies.

A major new trial from the charity is teaching the dogs to sniff out cancer from urine samples provided by a local hospital. So far they have had a 93% success rate.

The other major cancer that the dogs are working to identify is breast cancer – currently the most common in the UK with around 50,000 women being diagnosed each year.

Research is underway to find out whether breast cancer can be detected on a breath sample. If this is possible, it could revolutionise the way we diagnose and treat it in the UK.

In addition to urological cancers and breast cancer, the charity is currently exploring the possibility that the dogs can detect a number of other cancers and diseases, including: Lung cancer

Colorectal cancer

Bowel cancer

Animal cancers

Parkinson’s Disease

For more information visit www.medicaldetectiondogs.org.uk