Dog Trained To Sniff Out Thyroid Cancer
A team at the University of Arkansas for Medical Sciences (UAMS) have trained a dog to be able to sniff out thyroid cancer from urine samples.
The dog – a German Shepherd mix called Frankie – can recognise thyroid cancer, and differentiate it from thyroid disease, with an accuracy rate of around 88%.
In a trial involving 34 patients who were undergoing conventional treatment for either thyroid disease or thyroid cancer, Frankie was trained to lie down when he smells cancer in the patient’s urine, and to turn away when he does not. He made the correct diagnosis in 30 cases, with 2 false positives and 2 false negatives.
Why is this important?
Thyroid tumours are usually diagnosed by testing hormone levels in the blood, and by testing cells which are extracted with a needle. Dr Donald Bodenner, senior researcher and chief of endocrine oncology at UAMS, says that these diagnostic methods are often unreliable, and developing a reliable detection method with dogs might be able to prevent unnecessary surgery.
Dr Jason Wexler, an endocrinologist in Washington, DC, noted some of the possible applications of this study: “This is a fascinating, interesting study and it has high potential in areas of the world that may not have access to biopsy techniques.”
“There are many patients who are reluctant to undergo fine needle aspiration so I think that if you could design a technique where you have no invasive procedure that can have tremendous widespread appeal.”
Can we really swap dogs for doctors?
Others are less certain about the potential application of this study. Dr Emma Smith, from Cancer Research UK, warned: “Although there’s some evidence that some trained dogs can sniff out the smelly molecules given off by cancers, there have been mixed results on how accurate they are and it’s not really practical to think about using dogs on a wide scale to detect the disease.”
However, this doesn’t rule out the possibility that Frankie’s expertise could be put to some use in developing and improving methods of diagnosis. “Carrying out lab tests to understand what the dogs are smelling might help to inform the development of ‘electronic noses’ to detect the same molecules, which could lead to better diagnostic tests in the future,” says Dr Smith
So even if this test can’t be developed into a full-blown canine cancer unit, with consistent and accurate results, it might still provide great insights which improve detection, and decrease the needs for other more invasive procedures.
Dr Bodenner is continuing to pursue more strictly canine possibilities for now. He plans to extend the program in collaboration with Auburn University College of Vetinary Medicine, to train veteran sniffer dogs to turn their expertise from bombs to urine, in the hope of training a whole team of cancer detectors.
“The capability of dogs to smell minute amounts is unbelievable,” Dr Bodenner said.
“The medical community over the next few years is going to have a great appreciation [for them]. We would like to know what Frankie is smelling, nobody knows.”