These reports have prompted a number of formal studies and training efforts. Florida dermatologist Armand Cognetta collaborated with a police dog handler to train dogs to locate and retrieve tissue samples of melanoma that had been removed and stored in bottles. One dog named George proved 100 percent successful in detecting melanoma samples in tests, and in follow-on tests the dog was nearly 100 percent successful in detecting cancerous skin lesions in patients. Now
Cambridge University Veterinary School is seeking funding to develop “dognoses” of prostate cancer by training dogs to smell signatures of the disease in urine samples. “If the dogs can be trained to a high level of accuracy, which we think can be done, then many people can be screened a lot faster and a lot earlier,” said project leader (and certified canine hydrotherapist) Charlie Clarricoates. He estimates it takes about 70 to 100 repetitions over two to three weeks to train a dog to signal an odor; the question is whether or not the dogs will be repeatedly accurate enough for government licensing officials to accept and certify them as a medical diagnostic method. Those familiar with the capability of dogs’ noses are confident. While people have about 40 million olfactory receptors in their noses, dogs have about 2 billion. “Depending on what odors there are, dogs can smell from 1,000 to 100,000 times better than people,” said Paul Waggoner of the Canine & Detection Research Institute. “They are very much odor-guided.”
So are robot noses, being developed to detect the smell of lung cancer on a patient’s breath. One called Cyranose (named of course for another famous nose) is made by Cyrano Sciences and looks for high levels of alkanes and benzene derivatives indicative of lung cancer. Dr. Roberto F. Machado tested Cyranose on 59 test subjects, and it successfully separated them into a group of 14 with lung cancer, 25 with lung disorders and 20 who were healthy. A similar device imaginatively named the “e-nose” is being developed in Italy.