Frankie the Cancer-Sniffing Dog
Dogs have been called “man’s best friend” for the longest time, and they have even been know to save human lives. And it looks like they could save even more lives in the future, according to a team of researchers from the University of Arkansas for Medical Sciences (UAMS) in the US.
Frankie is a German Shepherd dog who had previously shown the team that he could be trained to sniff out thyroid cancer from a urine sample.
The thyroid is a gland in your neck that produces hormones to control how quickly your body uses energy and makes proteins, and controls how sensitive your body is to other hormones.
Compared to other types of cancer, thyroid tumours are actually quite rare and are more common in younger people than those over the age of 55. The disease is normally diagnosed by using a needle to extract cells that are tested to check hormone levels. As you can imagine, this is quite an invasive procedure and doctors and patients alike would welcome a less intrusive diagnostic method.
Dogs have 10-times the number of scent receptors in their noses as people do, making them capable of smelling unique smells. One of these types of scent is that of cancer, which releases organic compounds into the body and releases its own unique chemistry.
Our canine friends have already been proven successful when it comes to diagnosing bowel and lung cancer patients, so the Arkansas University team wanted to see what could be done for thyroid cancers.
Frankie was trained to lie down when he could smell thyroid cancer chemicals in a sample of urine, and turn away if the sample suggested benign thyroid disease. The team wanted to take Frankie’s abilities to the next level to see if they could be turned into a diagnostic tool.
Dr Donald Bodenner, the UAMS Chief of Endocrine Oncology, explained that detecting and diagnosing cancer of the thyroid can be very difficult. “It is often looking for a very small number of occurrences in a very large background of benign modules,” he said. He added that it is difficult for doctors to be certain a patient is cancer-free after surgery.
So, to put Frankie’s nose to the test, the team set up a trial that consisted of 34 patients visiting the hospital for conventional thyroid cancer testing.
Out of these 34 patients, Frankie was able to diagnose 30 cases correctly – the four misdiagnoses were two false positives and two false negatives. These results mean that Frankie’s testing was almost 90% accurate!
“The capability of dogs to smell minute amounts is unbelievable,” said Dr Bodenner, adding that the medical community is going to develop a great appreciate for our canine friends over the next few years.
Finding out just what it is that Frankie can smell in these samples that we cannot means researchers would be able to create a diagnostic tool with an electronic nose to “smell” cancer chemicals.
This isn’t something that the team has just leapt onto, either. “We have all looked at it from a skeptical, scientific standpoint,” said lead researcher Dr Arny Ferrando. “But the data just keeps leading us to the fact that this has remarkable clinical potential.”
Dr Emma Smith, Cancer Research UK’s Senior Science Information Officer, urged that we use this latest research with caution before more clinical trials have been carried out. “There have been mixed results on how accurate they are,” she explained, but agreed that the work could lead to better diagnostic tools in the future.
So, dogs are man’s best friend? It seems, it more ways than one.