A dog’s sense of smell—more than 10,000 times more sensitive than that of our own—has been exploited by humans for centuries. Whether it is finding hikers and skiers buried by avalanches in the Alps, or helping sniff out contraband drugs, the olfactory talents of man’s best friend are well known.
More recently, dogs have been recognized for being able to smell diseases such as diabetes and a range of cancers. Now, researchers led by Thomas Quinn, D.O., professor at Lake Erie College of Osteopathic Medicine have published data detailing the ability of three beagles to sniff out lung cancer with 97% percent accuracy.
“We’re using the dogs to sort through the layers of scent until we identify the tell-tale biomarkers,” said Quinn in a press release. “There is still a great deal of work ahead, but we’re making good progress.”
The results of the double-blind study were published in the July edition of The Journal of the American Osteopathic Associationand provide hope that dogs can help identify cancer specific biomarkers that can aid in the development of an inexpensive and effective tool for cancer screening.
The pups used in the study—all beagles— were trained for eight weeks and then selected for their olfactory acumen. For the study, the dogs were led into a room with blood serum samples at nose level. Some samples came from patients with non-small cell lung cancer while others were drawn from healthy controls. After thoroughly sniffing a sample, the dogs sat down to indicate a positive finding for cancer or moved on if none was detected. The dogs detected the blood samples from patients with lung cancer with 97% accuracy.
Quinn and his team are now involved in a broader study that also includes breast and colorectal cancer. In this study the researchers are capturing the breath of study participants in a face mask for the dogs to sniff. Early results indicate the dogs are as effective detecting cancer from the smell of a person’s breath as they from the smell of their blood.
Further studies are planned to fractionate the samples based on their chemical and physical properties to have the dogs sniff and to continue the process until specific biomarkers have been identified. The ultimate goal, the team said, is to develop and over-the-counter cancer screening test.
The hope is that an easy, early screening test will identify cancer much earlier and improve patient survival rates. The five-year survival rate for stage IA non–small cell lung cancer (NSCLC) is 92%. That drops to 13% in stage IIIC NSCLC, and after metastasis, the five-year survival rates range from 10% to less than 1%, depending on the stage.