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Originally published October 25, 2000
Dogs have been trained to detect bombs, sniff out
drugs, and even smell gas leaks in pipelines 20 feet below the ground. But can canines
detect cancer? Well, in Tallahassee, Florida, a 43-pound
Standard Schnauzer named George has been trained to successfully detect melanoma (a type
of skin cancer) on humans. In one case, George pointed out a mole that had previously been
examined by three different doctors and biopsied twice. After
doctors finally removed the lesion and sent it to the pathology laboratory for a
cell-by-cell analysis, they discovered that the patient had Stage II melanoma. If the mole
had been left alone for another year, the patient could very well have died from skin
cancer.
Armand Cognetta, MD, a dermatologist
whose specializes in skin cancer, has always been bothered by the fact that one in five
melanomas are not discovered in time to successfully treat the patient. Dr. Cognetta
believes that earlier methods of detection are needed to help treat melanoma before it
progresses to advanced cancer. After hearing a radio report of a dog who helped police
search for a body at the bottom of a lake by sniffing the air from the bow of a boat, Dr.
Cognetta decided to search the medical journals to see if canines had ever been trained to
help detect skin cancer.
A brief report in the 1989 Lancet medical
journal describes how a dog discovered a malignant (cancerous) skin tumor on her
owners leg. According to the report, the 44-year old woman insisted that doctors
examine the mole after her half Border Collie, half Doberman kept sniffing at the same
spot on her leg. After an excision and biopsy of the mole, doctors confirmed the presence
of melanoma. "This dog may have saved her owners life by prompting her to seek
treatment when the lesion was still at a thin and curable stage," wrote the
researchers.
Intrigued by the idea of training a dog
to detect skin cancer, Dr. Cognetta contacted Duane Pickel, an expert dog trainer and
former head of the Tallahassee Police K-9 Department, to ask if the task might be
possible. Pickel, who has trained over 15,000 military, police, and citizen dogs, answered
"yes" immediately and volunteered his Standard Schnauzer, George, who was
already a certified bomb-detecting dog.
"A dog can be trained to find
anything you need it to find," said Pickel, who spent eight years in the military
police K-9 service in addition to 22 years in the Tallahassee K-9 department.
Pickels longtime police dog, Duke, had contributed to 272 arrests.
To begin the training, Pickel taught
George to retrieve melanoma samples in test tubes. Gradually, Pickel began hiding the
tubes under furniture and in cabinets, rewarding George with cookies and treats when he
discovered the melanoma samples. Eventually, George was able to find a melanoma sample
when it was placed in one of 10 holes in a long rectangular box.
"It was actually easier to train
George to detect melanoma than it would be to train a dog to detect bombs or drugs,"
said Pickel. "With a cancer dog like George, he only has to learn to find half as
many items since there are many more components involved in the training of bomb-detecting
and drug-detecting dogs."
In April 1994, Dr. Cognetta and Pickel
took Georges training to the next level with Kim Edwards, RN, head nurse of the
outpatient surgical unit at Tallahassee Memorial Regional Medical Center. Edwards, who had
a family history of melanoma skin cancer and was at risk of the disease herself, was happy
to help.
Pickel designed a special,
low-to-the-ground examining table, and taped dozens of bandages to Edwards body.
Under one of the bandages was a live melanoma sample. Over more than a year, George
repeatedly sniffed the bandages on Edwards body until he could detect the bandage
with melanoma 99.7% of the time. Eventually, Pickel and Dr. Cognetta tested Georges
ability on seven skin cancer patients. Over a 10-month period, George was able to
correctly identify melanoma on six of the seven patients.
Georges success at detecting
melanoma has proven that dogs can play key roles in medical advancement. In fact, dogs
have also been trained to alert patients when they (the patients) are about to experience
epileptic seizures and to assist patients with severe Parkinsons disease. Dr.
Cognetta and other physicians believe canines could also be useful in helping to screen
for tuberculosis in poor communities.
According to Pickel, dogs can smell
220,000,000 (220 million) times better than humans. However, Dr. Cognetta says that dogs
will probably never be used in physicians offices because there are too many people
that need to be involved in the process: the patient, the physicians, the dog handler, the
dog, and possibly a nurse. Also, many patients may not approve of having a dog sniff their
bodies.
Nonetheless, understanding how dogs are
able to detect cancer by smell may help scientists develop new technology to help detect
melanoma and other cancers at earlier stages. In fact, researchers believe that dogs may
also be able to detect early-stage lung cancer by sniffing deep-breath samples.
Though scientists do not yet know
whether dogs smell enzymes, proteins, antibodies, or other components of melanomas,
further research with canines may one day allow them to develop new medical equipment. An
"electronic nose" or "smelling machine," designed to mimic the action
of a dogs nose, could one day help to save lives by detecting cancer early-stage
cancers when they are highly treatable.
Editor's Note: Duane Pickel's Standard Schnauzer, George, died of a brain tumor in late
2000 at age 11-1/2. Pickel continues to work with healthcare professionals, training dogs to
detect cancer. He is currently working with a Poodle named Ponce and a Border Terrier named
Connor at the National High Magnic Field Laboratory in Tallahassee, Florida where researchers
are trying to create a medical system that emulates how dogs smell cancer.
Additional Resources and References
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