Researchers from the Lake Erie College of Osteopathic Medicine may have taken an important step in improving the ability to detect lung cancer. Their study, recently released in the Journal of the American Osteopathic Association, successfully trained three dogs to use their superior smelling skills to identify cancerous blood samples. Though similar studies have been performed in the past, researchers are hopeful that these new findings will lead to a simpler lung cancer test for patients.
The beagles, chosen for their advanced olfactory receptor genes, were put through a rigorous eight-week training to learn how to tell the difference between blood samples taken from patients with lung cancer and those without. A beagle's sensitivity to smell is about 10,000 times more complex than that of a human, making them particularly equipped to tackle the task of sniffing out cancer.
The trained dogs were led into a room filled with punctured canisters that each contained a separate sample. Thirty positive samples were interspersed between 120 negative samples. The dogs were given the opportunity to sniff each sample and identify it as a positive finding by sitting down. If the sample was identified as negative, the dog would simply move on to the next canister. Amazingly, the dogs were able to differentiate the samples with 97 percent accuracy.
"We're using the dogs to sort through the layers of scent until we identify the tell-tale biomarkers," Dr. Thomas Quinn, lead author of the study and professor at Lake Erie College of Osteopathic, said in a press release. "There is still a great deal of work ahead, but we're making good progress."
Lung cancer is currently the leading cause of cancer related death worldwide for both men and women. Those diagnosed with more advanced lung cancer have much lower five-year survival rates than stage 1 patients, which is why early detection is critical. Recently, CT scans became a better option for detection, but there is still the opportunity for the cancer community to find an inexpensive, effective, and simply administered test that can be easily available to the public. Dr. Quinn hopes that his work with the dogs will eventually lead to an over-the-counter screening product, similar to a pregnancy test.
Though it was a small sample, the study has researchers excited.
"For lung cancer, a cancer, where more than 50% of newly diagnosed patients are diagnosed at a stage IV with low survival rate, early detection is a very important concept. Historically, we haven't had a very good screening test for lung cancer until recently when data showed potential benefit of CT screening. Unfortunately, as of now, and despite adaptation and recommendations from major cancer societies, still only small percentage of eligible patients are undergoing the CT screening. Therefore, there is a major desire to find new, simple and innovative methods for early detection and the method presented in this study may be one of them," said Dr. Rami Manochakian, a member of the American Lung Association's Lung Cancer Advisory Panel and thoracic medical oncologist at Mayo Clinic, Florida.
"We know that circulating tumor cells exist in the blood. So, it is definitely exciting that here comes this study telling us that dogs can smell something in the blood that is linked to cancer," Dr. Manochakian continued. "However, can we try to identify the compound they are sniffing which could help us isolate it and measure it in the blood? The second important question: Is the compound being sniffed being shed in the blood in patients with more advanced stage cancer only or in patients with early stage cancer as well which is a key point if we envision this test being a tool for early detection."
Dr. Quinn and his team have already begun a second iteration which requires the beagles to identify multiple types of cancer by simply smelling a patient. They hope to then move on to a third study that will further separate the samples and present them back to the dogs until the correct biomarkers for each cancer is identified.
For now, we encourage all those concerned about their lung cancer risk to take our screening eligibility quiz and talk to their healthcare provider about screening with a low-dose CT scan.
Blog last updated: April 13, 2020