The same species that submitted itself to experimentation for treatments to human cancers is now getting a cure with N.C . State’s first canine bone marrow transplant.
In 2008, Dr. Steven Suter , assistant professor of oncology, began performing bone marrow transplants, BMT , on dogs. N.C . State is the only university in the world that offers this treatment. While private practices do exist, mainly on the west coast, they have treated few dogs. People have traveled from across the country to utilize these services.
“Once I became an oncologist, I realized that this could probably be done now in a clinical setting if the appropriate machines could be found, apheresis machines. Once I got a hold of some of these machines, I started collecting peripheral blood progenitor cells from a few research colony dogs. After I showed we could do that, we moved on to start transplanting client-owned dogs. We opened our canine BMT unit in October 2008,” Suter said.
Until recently, the transplants used stem cells from the dogs’ own blood, so only those who had a disease in remission could be treated. The treatment was typically used on dogs with lymphoma.
“The cure rate of dogs with lymphoma treated with chemotherapy is less than 5 percent, so I felt we could do better on that front with BMT ,” Suter said. “We have modified the protocol extensively since the first 24 dogs, so we are hoping it will now be better.”
However this all changed with two Cavalier King Charles Spaniels, Chip and Zeke, earlier this year. Zeke was diagnosed with acute lymphocytic leukemia in December 2011. This disease could only be treated by use of donor bone marrow. Chip, a littermate , was the prime choice.
“We do require a donor, since we can not harvest progenitor cells from the patient. Leukemia patients have too many cancer cells floating around in their blood, so the machine would harvest them also. So, we find a matched donor who does not have cancer obviously, and harvest the cells from them,” Suter said. “We don’t use this procedure regularly to treat dogs with leukemia … we’ve treated two dogs with leukemia. We use it mainly to treat dogs with lymphoma, which is a very different disease.”
The owners of the dogs met for the first time at N.C . State for the procedure to take place.
Jason Hefner, a fourth year in veterinary medicine, worked with Zeke while he was here.
“To our knowledge, only one previous case has been treated with a donor. Zeke had a great disposition, and I looked forward to visiting him each morning for his treatments. Zeke is now in New York and looking forward to a happy and healthy life,” Hefner said.
Prior to curing dogs of leukemia, transplantation was tested on dogs before it was available for humans. It only made sense to Suter to return the favor.
“Dogs have been the model for bone marrow transplants since about 1967…95 percent of human transplant protocols were perfected in dogs first,” Suter said.
Despite the situation with Zeke, the treatment of leukemia is not the main focus for this protocol. Additionally, while the procedure is available to the public, it is expensive, averaging $15,000.
Joe Borneman , prospective vet student and senior in biology, voiced his concerns about the number of pet owners who can afford this procedure.
“For most pet owners, treatment of leukemia is not possible unless the pet has insurance. There’s chemotherapy, radiation therapy, and in some cases, a bone marrow transplant is necessary or will improve the likelihood of survival, but it can’t always be afforded by the owner,” Borneman said.
At the moment, the biggest problem is building up a database of donors, similar to the one which exists for humans. For this, the University will need volunteers to bring in their dogs.
“We actually hope to do more and more allogeneic transplants as we get better at the matching process. We currently have the matching done at the Fred Hutch [Cancer Research Center] in Seattle, and it’s time consuming … and very expensive,” Suter said. “We have a faculty member here, Dr. Paul Hess, who is working on getting the matching procedure up and running here. It will be much quicker and cheaper. Once he does that, I think we will be able to perform more allogeneic transplants,” Suter said.
While the transplants are more challenging, Suter believes their cure rates may be higher if they start to use them for lymphoma patients also. At the moment, they are limited to select cases.