A German shepherd-mix named Frankie was able to detect thyroid cancer in patient urine samples with 88 percent accuracy, according to a research team from the University of Arkansas for Medical Sciences at the annual Endocrine Society meeting.
Thyroid cancer is when abnormal cells grow in the butterfly-shaped gland of the neck. In 2015, there were approximately 62,450 new cases diagnosed in the U.S., with 1,950 deaths from the disease, according to estimates from the American Cancer Society. The cause of the disease is unknown, but similar to other cancers, changes in the DNA of an individual’s cells may play a role.
Image: Male thyroid gland anatomy in X-ray view. Credit: goa novi / Shutterstock
Frankie, the scent-trained canine, sniffed out the correct diagnosis in 30 out of 34 people with the disease. Of the four patients with thyroid cancer that the canine missed, two were false-negatives and the other two were false-positive results. While impressive, don’t expect dogs to make an appearance at your next checkup. Researchers are hoping to identify the chemicals Frankie is smelling in order to construct new diagnostic tests.
“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,” said Dr. Emma Smith, from Cancer Research UK, to the BBC.
Current diagnostic techniques include fine-needle aspiration biopsy, which is when a needle is inserted into the thyroid gland to obtain a tissue sample. The cells in question are then sent to the lab and examined under a miscroscope to determine if they are cancerous or benign.
To carry out the dog-directed approach instead, Frankie was trained to recognize the smell of thyroid cancer in urine samples. If the urine was cancer-positive to his sensitive nose, he alerted his handler by lying down. At the time of the study, the status of the urine sample was unknown to both the dog and the handler to ensure the canine’s choice was unbiased. With a nose tens of thousands of times more powerful than our own, Frankie sniffed out the correct diagnosis almost 9 out of 10 times.
There have been other studies in which dogs have showcased their incredible cancer-detecting abilities. In one, the dogs were able to identify prostate cancer with 98 percent accuracy. As Dr. Donald Bodenner, the chief of endocrine oncology at UAMS, told the BBC: “The medical community over the next few years is going to have a great appreciation [for them].”