Researchers Hope Dogs With Cancer Will Help Them Take Bite Out of Human Disease

By SHERYL UBELACKER

GUELPH, Ont. (CP) – Nora, a three-year-old golden Labrador retriever, rushes from her owner to the vet and back again, wagging her tail, looking for caresses and “smiling” as only dogs can. To look at her, one would never know she had just undergone a chemotherapy session for bone cancer.

But the treatment at the Ontario Veterinary College at the University of Guelph is not only aimed at helping this particular canine – it will also provide data for a new research institute that is seeking to advance knowledge about cancer in humans.

“There are lots of dogs out there and they’re living longer so they’re more likely to develop cancer because it is primarily, as in people, related to age,” said Brenda Coomber, a professor of biomedical science and co-director of the Institute for Comparative Cancer Investigation.

The new institute, which will include the veterinary college’s oncology unit and dozens of researchers from disciplines across the university, is intended to “facilitate collaborations for translational biomedical discovery,” said Coomber.

“Which is a fancy way of saying: How do we get the information that comes out of research labs to a point where it becomes useful for the clinical care and diagnosis of people?”

Comparing canine disease to that in their human companions isn’t as much of a stretch as some might think.

Dogs develop many of the same types of cancers as people and the disease behaves in similar ways in both species. It is also common: it’s estimated that one in four dogs will develop some type of malignancy.

And dogs, in particular, are a much closer model of human physiology than are laboratory mice and rats, the latter long used to investigate diseases and to try out new drugs before testing in humans, Coomber said.

“There’s been an increasing appreciation now that although laboratory rodents and similar models are tremendously powerful, and we’ve made enormous advances in understanding cancer using those models, there is a disconnect between what mice and rats do and what happens in people.”

For one thing, researchers have to induce tumours in mice, while in dogs they occur naturally. In rodents, tumours are usually driven by a single genetic mutation, while in dogs and humans, there may be multiple genes involved. The rate of tumour growth is also much faster in rats and mice, whose lifespans are comparatively short.

“The whole system gets lost in translation from mouse to human,” said Coomber. Who knows how many experimental anti-cancer therapies that seemed promising in rodents but didn’t pan out in humans were really “lost opportunities?”

“Perhaps if we’d had a chance to look at some of those approaches in a model like a dog with a naturally occurring cancer, where the tumour’s taking years to develop . . . we would have been able to have more of a sober second thought about how these things do work.”

While people may end up the ultimate beneficiaries of this research, there’s no question of the pets being used as sacrificial fodder on the altar of human medicine.

“We are never talking about inducing tumours in dogs or rounding up thousands of pound dogs and seeing if they have tumours,” stressed Coomber. “That’s not what this is about.”

“We always have to keep in mind the quality of life of the animal.”

The work is also intended to improve the health of pets that come to the clinic at the veterinary college, said Dinaz Naigamwalla, a staff veterinarian who specializes in oncology.

“We’re always looking for new treatment options, new drugs, new protocols for our dogs with cancer,” said Naigamwalla, noting that her clinic sees about a dozen dogs a day for treatment.

“And the more information we do get, the more likely we are to come up with different treatment options that can prolong their lives even more.”

Prolonging the life of Nora is the hope of her owner, Nelson Perel, a lawyer from Lancaster, N.Y., near Buffalo.

Perel has been bringing Nora – named after singer Nora Jones by his 25-year-old daughter – to the Guelph clinic pretty well monthly since December, when veterinarians here confirmed the dog’s diagnosis of osteosarcoma, a bone cancer that appears not to have spread to her lungs.

In March, surgeons at the college removed a tumour from a bone under Nora’s eye and she has since been having chemo to keep the cancer at bay.

The injections can cause diarrhea and vomiting, but Nora didn’t suffer those side-effects, said Perel, who makes the four-to five-hour round trip excursion to Guelph with his pet in the back seat of the car.

“She showed no ill effects whatsoever from the chemo in terms of activity, appetite, any of that stuff.”

The vets have told him that with surgery and chemo, Nora has a 70 per cent of surviving a year, but she could live much longer.

Perel estimates he will have spent between $5,000 and $10,000 once treatment is completed, a cost he says his family is able to afford and does not begrudge spending on their beloved pet.

“I think because of what I understood about the prognosis . . . the chances of her doing well were such that it just seemed worth doing,” said Perel. “She’s a very good dog.”

“The sense that I have, rightly or wrongly, is that if we had done nothing, she would have died, she would be gone.”

Coomber said work in dogs with osteosarcoma in a limb – the same type of cancer that struck Terry Fox – has led to tumour-removal surgery that avoids amputation, a procedure now being tested in children with the disease.

And because there are so many of them, dogs are like the proverbial canary in a coal mine, although on a much broader scale – and that makes them ideal surrogates for trying to untangle the mysteries of cancer.

“Dogs get cancer at a high rate. They live in the same houses as we do. Often they eat the same food, even if they shouldn’t . . . And dogs are watchdogs for environmental contaminants,” she said.

“Cancers that develop in these dogs are an enormous resource. Figuring out what’s going on in a tumour, finding out about the disease, it will absolutely be applicable to people.”