How Animals can Save us
“DOGNOSES.” More than man’s best friend or a Frisbee-catching champion, dogs are trained to detect bombs, sniff out drugs, find earthquake and avalanche victims and, now, detect cancer. In Tallahassee, Fla., a Schnauzer named George was trained to detect melanomas, a type of skin cancer that many times is not discovered in time to successfully treat the patient. Armand Cognetta, M.D., a dermatologist specializing in cancer in Tallahassee teamed with veteran police dog trainer Duane Pickel and senior study author James Walker, Ph.D., head of the Sensory Research Institute at Florida State University in Tallahassee, to train George, and another dog, Breeze, to sniff out melanoma.
Over 47,000 new cases of melanoma are diagnosed every year in the United States. Current medical practice relies primarily on unaided visual inspection, although many melanomas are colorless rendering them invisible. This is part of the reason why some melanomas are not discovered in time for successful treatment.
A 1989 study in The Lancet highlighted a patient whose dog persisted in exploring a spot on the patient’s leg that was found to be melanoma. It was this work that spurred Walker’s team to begin their study. The researchers trained George and Breeze using methods normally used in canine olfactory detection of drugs and explosives. They demonstrated reliable localization of melanoma tissue samples hidden on the skin of healthy volunteers. George confirmed melanoma in five patients that was clinically suspected and later confirmed to be melanoma. Breeze duplicated these findings.
According to Paul Waggoner, Ph.D. director of the canine program at the Institute for Biological Detection Systems at Auburn University in Alabama, dogs are equipped with the right smelling tools and are easily handled by people — two critical factors for their success in the detection field. He says, “Dogs can smell from 1,000- to 100,000-times better than people and they are not only odor-guided, but have a vast capability to detect one odor in an odor-rich environment.”
Understanding how dogs detect cancer may help develop new technology detect cancers earlier. Although the compounds a dog might smell in a cancer sample are unknown, research in this area may lead to new ‘smelling machines’ designed to detect cancer in the early stages.
Walker and colleagues are also discussing ways to detect early-stage lung cancer using bronchoalveolar lavage samples from patient’s lungs.
Dr. Barbara Sommerville, from Cambridge University in Cambridge, England is also using dogs to sniff out cancer. She and colleagues have applied for funding to test dog’s ability to detect prostate cancer in urine samples, a test that may provide a better early warning system than those in place. The current test is a serum test that turns up a lot of false positives and some false negatives. Because the next step is to perform multiple biopsies, this presents a problem. Dr. Sommerville doesn’t know what the dogs will smell, but she believes urine from a prostate cancer patient will be different.
Is the doctor’s office the final frontier for the hound? It is unlikely because dogs like to move around, which is impractical in a medical setting. The most likely scenario is that this research will lead to better instrumentation to detect cancers early.