Dogs vs. AI: Which Is Better At Detecting Cancer?

Specially trained beagles were able to detect with almost 100 percent accuracy the presence of “non-small-cell lung carcinoma” (NSCLC), the deadliest type of lung cancer, in blood samples of patients.

NSCLC accounts for some 85 percent of all lung cancers. It’s also the second most common cancer doctors diagnose among patients in the United States.

They’re relatively insensitive to chemotherapy, compared to small cell carcinoma, thereby making early detection vital. Getrting to grips with lung cancer in its early stages can allow doctors to find and apply the most effective treatments. That’s where the beagles came in.

A research team led by Prof. Thomas Quinn from Lake Erie College of Osteopathic Medicine in Erie, Pennsylvania worked with three beagles whom they trained to sniff out NSCLC in plasma (blood) samples.

It’s well known the olfactory acuity of a dog is at least 10,000 times more sensitive than that of a human. Dogs’ superior smelling skills are likely due to their more expansive olfactory epithelium and olfactory receptors. It’s also due to their ability to retain air in their nasopharynx during exhalation.

The research team chose beagles because these dogs are members of the scent hound family and have 225 million olfactory receptors. In comparison, humans have 5 million olfactory receptors. A scent hound is a type of dog people traditionally bred to chase small game animals during a hunt.

The team trained the beagles to sit down when they could smell cancer, or to move on if the sample was from a healthy person. In the tests, the dogs successfully made the distinction between the two types of plasma samples. They identified the presence of NSCLC with 97.5% specificity and 96.7% sensitivity.

"We're using the dogs to sort through the layers of scent until we identify the tell-tale biomarkers," said Prof. Quinn.

He said while there is still a great deal of work ahead, “we're making progress.”

Researchers are completing a study testing the beagles’ ability to identify several other forms of cancer, including breast cancer and colorectal cancer.

Theey’re also interested in separating samples collected from cancer patients into fractions containing specific biomarkers, so they can train the beagles to identify separate signs associated with the presence of cancer.

Artificial intelligence (AI) is a very long way off from accomplishing the impressive feat of these beagles. An article in June 2018 reported that a project had been started to developi an AI that can smell human breath and learn how to identify a range of illness-revealing substances people exhale.

There has been no word of any Ai being taught to detect cancer in human blood by smelling or detecting it through the air.