A Buckinghamshire scientist whose dog apparently "sniffed out" her breast cancer is leading research to see if a breath test for its detection is possible.
Medical Detection Dogs chief executive Dr Claire Guest was training dogs to detect other cancers, when she said one of them "started to warn her".
She was subsequently found to have an early stage breast tumour.
Now in remission, Dr Guest is training dogs to recognise the cancer from a breath sample, in the hope an electronic nose can be developed.
Medical Detection Dogs is a charity that works with researchers, NHS Trusts and universities to train specialist dogs to detect the odour of human disease.
The charity was started in 2004 after a letter from Dr John Church to medical journal The Lancet claimed dogs could detect bladder cancer.
Dr Guest said stories of dogs finding their owners' cancer had been reported for a while.
"We started to wonder that if dogs were finding it by chance then perhaps we could actually train dogs to do this reliably," said Dr Guest.
The charity started to work with dogs, and they can now pick out cancer samples from control samples, but research has been mainly limited to bladder and prostate cancer.
Dogs are now being taught to detect breast cancer from a breath tube, after an animal Dr Guest was training to detect other cancers started to warn her.
"I was a bit bemused as to what she was doing, but I was subsequently found to have a very early stage breast tumour," she said.
"It was very deep and had my dog Daisy not warned me, I was told it could have been very serious and life-threatening because by the time I felt the lump it would have been very advanced."
Now in remission, the scientist has joined forces with her surgeon and other cancer specialists to search for the clinical proof that breast cancer can be "sniffed out".
In particular, they are looking to see if dogs can recognise it reliably from a breath test.
"There is a huge amount of potential for this work, not only in finding out where cancer is present but also in the development of an electronic nose in the future," said Dr Guest.
"A dog is in fact a very, very specialist pattern recognition bi-sensor - but he has got a waggy tail.
"He can tell us when something is there and when it's not and how quickly it disappears [when a sample is in contact with the air] and they can tell us how difficult it is to find.
"If we can find out how the dog is doing it then we can make machines in the future that could screen our breath and our urine for cancer volatiles."
This research is at a very early stage and the next step will be a clinical trial with samples from local hospitals.
"We need to find out how reliably dogs can indicate this and also if they can reliably indicate early grade and stage, because that would be the key for survival," said Dr Guest.
Latest figures from Cancer Research UK show nearly 50,000 people are diagnosed with breast cancer each year in the UK and just under 12,000 die.
The hope is this research "has the potential to save thousands of lives".
"All our work with cancer is incredibly exciting," added Dr Guest.
"Everybody has a personal story [about cancer] and we know that anything that can assist in our fight against cancer is worthwhile, we know we can make a difference."