Dogs that could stop men dying by sniffing out prostate cancer


The first signs something was wrong were barely perceptible, but — unlike many middle-aged men — Brian Harris monitored his health closely and promptly went to his GP.

At first, his doctor told him the mild ache in his groin was a urine infection. But after three courses of antibiotics failed to stop his growing discomfort, he was referred for a blood test which revealed his levels of PSA — the protein the prostate gland produces — were slightly raised. A warning he might have prostate cancer, yes, but far from a conclusive diagnosis.

For this, Brian, 68, needed to undergo a transrectal ultrasound guided biopsy — an invasive procedure in which a needle was inserted into the prostate through the wall of the rectum to remove 12 samples.

That, too, failed to confirm he had cancer. It was only after a second, more invasive biopsy — under general anaesthetic when 24 pieces of tissue were removed — that malignant cells were detected.

Two-and-a-half years after his first symptoms, he was finally given the diagnosis. ‘I thought it was the end of my life,’ admits Brian, who is married to Marian, 68.

In 2007, two months after his diagnosis, Brian underwent surgery to remove his prostate and 12 lymph nodes. Although the cancer returned in 2010, requiring radiotherapy, the father-of-two, who has three grandchildren, is now cancer-free.

But what strikes Brian as much as his good fortune is the time it took for his diagnosis. ‘The biopsies were incredibly intrusive, and there was no guarantee the needle would find anything,’ says Brian, a retired IT consultant from Sittingbourne, Kent. ‘The chances of hitting cancerous tissue are a bit like trying to throw a dart at a bullseye blindfold, and because doctors couldn’t find cancer during that first biopsy, it spread.’

The Mail is campaigning for earlier and easier diagnosis, and Brian knows better than most about an unorthodox but incredibly promising new method being tested. 

His son, Rob, 40, is a trainer for Medical Detection Dogs (MDD), a charity that uses ‘bio-detection dogs’ to sniff out diseases. Dogs have an extraordinary sense of smell — 40 times more powerful than humans — and can detect odours at a concentration of one part per trillion; this means they can smell the distinctive smells that different diseases develop at the very earliest stages.

The diseases the charity’s 31 dogs are being trained to detect range from malaria to Parkinson’s, but the focus is on prostate cancer.

Since 2015, Medical Detection Dogs — led by CEO Dr Claire Guest who set up the charity in 2008 with Dr John Church, a retired orthopaedic surgeon — has been working on a prostate cancer clinical trial with Milton Keynes University Hospital NHS Trust.

‘We hope within a couple of years it will confirm previous studies we have conducted that suggest dogs have a 93 per cent success rate,’ says Dr Guest. ‘The PSA test is problematic because of its false positives: three out of four men who receive a positive result won’t have cancer, and the next diagnostic step is to insert a needle into their prostate. Unsurprisingly, many prefer to assume they don’t have the disease and opt out.

‘If the trial proves our dogs’ reliability in detecting this cancer, it could pave the way for a system to support the current, inadequate system of diagnosing the disease.’

One of the seven dogs assigned to the trial at the charity’s Milton Keynes training centre is Rob’s cocker spaniel, Kizzy, nine.

‘I didn’t know Kizzy when I had cancer, so she hasn’t detected it on me,’ says Brian. ‘But I’ve watched her at work and it’s amazing. If dogs were being used to support the NHS when I got cancer, they could have paved the way for a quicker diagnosis.’

MDD started using its dogs for prostate cancer in 2012 after Dr Guest was contacted by an Italian doctor whose patient had tested negative for the disease, but the doctor had his doubts. Dr Guest recruited Daisy, her Labrador and a trained sniffer dog, to help.

‘Out of eight anonymous urine samples, she detected only his as being cancerous,’ recalls Dr Guest. The doctor called his patient for a second test, which proved positive.

Sadly, Daisy died last month, but with that test she became the charity’s first successful sniffer.

The clinical trial uses anonymous urine samples — some healthy, some cancerous — in glass pots sent from Milton Keynes Hospital.

Each pot is put on a ‘carousel’ — a stainless steel mechanism with eight arms.

‘We’ve trained the dogs to walk around the carousel before stopping and sitting by a sample they sniff cancer in,’ explains Dr Guest. The dogs tend to be Labradors or cocker spaniels, on account of their curious, sociable natures.

They need a minimum six months’ training, which costs the charity £11,000 per dog, after which most can correctly sniff prostate cancer within a minute. Each dog works a minimum of three shifts a week, which each comprise three 20-minute stints at the carousel.

Dr Guest, awarded an honorary Doctorate of Science in 2011 for her pioneering work, isn’t suggesting her dogs take the place of doctors. ‘But,’ she says, ‘they could offer invaluable supporting information to make an initial diagnosis more accurate, as well as helping doctors develop their ultimate aim: a testing machine that mimics a dog’s meticulous sense of smell.’

For Brian, not to mention the thousands of men with prostate cancer, it would be a welcome advance. ‘The current system needs to improve, and if clever dogs such as Kizzy can help doctors, I am in wholehearted support,’ he says.





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