Training dogs to sniff out cancer
Joshua A Krisch, NYT News Service | Sep 14, 2014, 06.49AM IST
McBaine, a bouncy black and white springer spaniel, perks up and begins his hunt at the Penn Vet Working Dog Center. His nose skims 12 tiny arms that protrude from the edges of a table-size wheel, each holding samples of blood plasma, only one of which is spiked with a drop of cancerous tissue.
The dog makes one focused revolution around the wheel before halting, steely-eyed and confident, in front of sample No. 11. A trainer tosses him his reward, a tennis ball, which he giddily chases around the room, sliding across the floor and bumping into walls like a clumsy puppy .
McBaine is one of four highly trained cancer detection dogs at the center, which trains purebreds to put their superior sense of smell to work in search of the early signs of ovar ian cancer. Now, Penn Vet, part of the University of Pennsylvania’s School of Veterinary Medicine, is teaming with chemists and physicists to isolate cancer chemicals that only dogs can smell.They hope this will lead to the manufacture of nanotechnology sensors that are capable of detecting bits of cancerous tissue 1100,000th the thickness of a sheet of paper.
“We don’t ever anticipate our dogs walking through a clinic,” said the veterinarian Dr Cindy Otto, the founder and executive director of the Working Dog Center. “But we do hope that they will help refine chemical and nanosensing techniques for cancer detection.”
Since 2004, research has begun to accumulate suggesting that dogs may be able to smell the subtle chemical differences between healthy and cancerous tissue, including bladder cancer, melanoma and cancers of the lung, breast and prostate. But scientists de bate whether the research will result in useful medical applications.
Dogs have already been trained to respond to diabetic emergencies, or alert passers-by if an owner is about to have a seizure. And on the cancer front, nonprofit organizations like the In Situ Foundation, based in California, and the Medical Detection Dogs charity in Britain are among a growing number of independent groups sponsoring research into the area.
A study presented at the American Urological Association’s annual meeting in May reported that two German shepherds trained at the Italian ministry of defense’s Military Veterinary Center were able to detect prostate cancer in urine with about 98% accuracy, far better than the prostatespecific antigen (PSA) test. But in another recent study of prostate-cancer-sniffing dogs, researchers reported that promising initial results did not hold up in rigorous double-blind follow-up trials.
But McBaine remains unaware of the debate. After correctly identifying yet another cancerous plasma sample, he pranced around the Working Dog Center with regal flair, showing off his tennis ball to anyone who would pay attention. In an industry saturated with hundreds of corporations and thousands of scientists all hunting for the earliest clues to cancer, working dogs are just another set of (slightly furrier) researchers.