Cancer research centers may have a new tool for diagnosing tumors that don’t involve machinery and could be the wave of the future in early detection of lung cancer. Groundbreaking research suggests that dog’s unique olfactory ability allow them to identify the presence of cancer just by catching a whiff of a patient’s breath.
The suggestion of allowing dogs to identify lung cancer was first published in a medical journal in 1989. One study in 2004 and one in 2006 had promising results. Although preliminary studies only involved a small number of patients, the 2006 report claiming 99% accuracy in detecting lung cancer. However, in a 2011 study lung cancer was identified with 71% sensitivity and 93% specificity.
On the assumption that further studies should corroborate the initial results, researchers believe that dogs are akin to their use in detecting drugs, bombs, and missing people. There were recommendations that dogs should be confined in labs to isolate specific compounds they can identify with the use of gas chromatograhs. In a recent development, the use of breathalyzer that changes color according to the compounds found in the breath could indicate the presence of cancer.
At the offices of Medical Detection Dogs, a Milton Keynes-based charity launched in 2008, dogs are trained to detect cancer in human urine. The findings published in a medical journal in 2004 were thought to be the new wave in cancer detection. However, dogs are only used in laboratories. It would be unethical to use them in the presence of patients.
While the human brain is dominated by the visual cortex, dog’s brains are controlled by their smell or olfactory cortex, which is 40 times larger than human’s. Their olfactory bulb has between 125 million to 220 million smell sensitive receptosr, which is 100,000 to a million times more reactive than humans. However, the key to the dogs’ success is early detection.
At the offices of Medical Detection Dogs, they see the dog’s work as a way to teach them about caner, which could be used in diagnosing cancers in the future. Dogs are currently trained to smell changes in people with narcolepsy, diabetes, and Addison’s disease.
A recent study conducted at the Schillerhöhe Hospital in Germany concluded that dogs have the ability to recognize the scent of certain organic compounds in the human body, which are linked to the presence of lung cancer. This scientific breakthrough is remarkable news as it proves that canine companions may be instrumental in the early detection of the traditionally hard to detect disease.
This research suggests that cancer could have a distinct scent produced by the chemical compounds of the disease which circulate through the body that dogs can detect. In past experiments, dogs have been accurate in sniffing breast cancer, ovarian cancer, colon cancer, and melanoma.
During the experiment, researchers filled 220 test tubes with breath samples from patients with and without lung cancer. Two German Shepherds, a Labrador and an Australian Shepherd were then brought in to sniff each sample. The dogs were instructed to lie down in front of vials of test tubes which contained breath samples of lung cancer infected patients and touch their noses to them. The dogs collectively identified 71 out of 100 patients infected with the disease. In addition, they correctly identified 93% of the cancer-free samples.
However, researchers have not yet singled out the exact components that enable cancer detection by dogs, which could be the new wave of the future. Scientists are hopeful that further studies could identify the chemical signature in early cancer detection.
Written by: Janet Grace Ortigas