Women at high risk of breast cancer could be screened for the disease by simply breathing into a tube which is then sniffed by a specially trained dog, in a new clinical trial after UK scientists found the animals are highly accurate at detecting other cancers.
A charity is now embarking on a landmark trial to establish if the dogs can accurately detect breast cancer from samples of breath which if proven would ‘revoluntionise’ how doctors think about the diagnosis of all cancers, the researchers said.
The animals working for Medical Detection Dogs in Buckinghamshire have already been shown to be more reliable at detecting prostate cancer than current blood tests, with 93 per cent accuracy when sniffing urine samples.
The results of the prostate cancer trial were published in the British Medical Journal and other reputable scientific publications so now the team are moving on to breast cancer.
Dr Claire Guest, a behavioural psychologist and founder of the charity, said her dog Daisy alerted her to her own breast cancer when they were working on the prostate cancer trial.
Daisy, a fox red labrador, persisted in jumping at Dr Guest’s chest and after medical tests, a deep seated early tumour was found.
Daisy has worked on 6,000 urine samples and has been found to be 93 per cent reliable in detecting prostate cancer.
Early studies, published in medical literature, have suggested dogs can detect bowel and lung cancer in breath samples.
Now six other dogs will be trained to sniff for breast cancer in breath samples for the new trial, which has alreday begun.
The best four will taken forward and tested in the trial using samples from 1,500 women.
Dr Guest said: “We use high drive, working breeds of dogs, like labradors and spaniels. They work for treats and biscuits but they genuinely love to work. They all live in people’s homes, they come in to work in a lab and then go home at the end of the day.”
The dogs are trained to stare intently at the sample when they believe it is positive for cancer.
It is thought the dogs, which can detect scent in one part per trillion, are sniffing out volatile substances given off by cancerous cells.
Dr Guest said: “It is logical that the dogs can detect prostate, bladder and renal cancer in urine samples but detecting breast cancer in breath is something different.
“I genuinely do not know what we are going to find. It is a question that needs answering. If it is found that dogs can detect it, it will change what we know about the diagnosis of all cancers. After all the blood flows around the tumour and then around the lungs.
“If proven it would have a significant impact on what we consider possible in the diagnosis of cancer.
“High risk young women, who are too young for routine, regular mammograms could breathe into a tube every six months and find out quickly and painlessly if they have cancer.”
In the long-term it is hoped the substances that the dogs are detecting can be identified and electronic noses created to pick them up.
But in the medium-term dogs can be used, Dr Guest said.
The charity also trains dogs for use by diabetic patients as they can spot signs their blood sugar is dipping and prompt them to take action. There are 50 medical assist dogs working in this way in the UK at present.
Sally Greenbrook, senior policy officer at Breakthrough Breast Cancer, said: “We know that work has been ongoing in this area for some time and we welcome any research that could improve the early detection of breast cancer.
“We will be watching this trial with interest to see if medical detection dogs can make a real difference to the early detection of breast cancer in the future, although it is likely to be several years before the results of this trial are available.
“Mammography is the gold standard for screening women aged over 50, so in the meantime we encourage all women to attend their breast screening appointments when invited. Women younger than 50 are not routinely invited to breast screening as it is not as effective in younger age groups, this is why we recommend that all women are breast aware. This means looking out for any changes and reporting anything unusual to their doctor.”
Dr Kat Arney, Cancer Research UK’s science information manager, said: “It’s nice to see that our four-legged friends are being recruited to help in the fight against cancer, as we know that some dogs can sniff out the molecules given off by tumours.
“But although it’s not practical to use dogs to detect cancer in the general population, the results of this study – once it’s completed – could inform laboratory tests to develop ‘electronic noses’ that might diagnose cancer earlier.”