By Jessica Tremayne
North Carolina State University is the only university in the country to offer autologous bone marrow transplants (BMT) for dogs with lymphoma—one of the most common canine cancers.
Dr. Steven Suter, VMD, MS, Ph.D., Dipl. ACVIM (Oncology), an assistant professor of oncology at North Carolina State University’s College of Veterinary Medicine, has been performing the transplants since October 2008. He says that a 40-50 percent cure rate is reported in humans with B-cell lymphoma using the same procedure, although the canine data is still tentative.
“When do you say a dog is cured?” Dr. Suter asks. “For people it is five years out [after the transplant procedure]. For dogs I estimate we can say two years after treatment is a success. In the first group of 24 dogs with B-cell lymphoma that we treated, eight are long-term survivors.”
Dr. Suter started providing this service with the hope that the procedure could be perfected and performed in the specialty clinical setting. Since the inception of the project, Dr. Suter has continued to modify the protocol.
“We now use a much higher dose of Cytoxan, which is given at 750 mg/kg,” Dr. Suter says. “This procedure is an alternative to half-body radiation. After diagnosis with lymphoma by the patient’s oncologist, chemotherapy will induce a clinical remission. This is then followed by high-dose Cytoxan, which is given by the local oncologist.
“The patient then comes to NC State, where tests are performed to confirm remission,” Dr. Suter continues. “We give subcutaneous doses of Neupogen, a human drug that drives CD34+ progenitor cells [also called bone marrow stem cells] from the bone marrow into the peripheral blood. The patient is connected to an apheresis machine and the bone marrow stem cells are harvested.
“The collected cells are refrigerated while the patient undergoes 11Gy of total body radiation over a period of two days,” Dr. Suter says. “Immediately after TBI, the stem cells are infused into the patient via an IV catheter. The infused cells then start producing new, healthy peripheral blood cells in approximately two weeks.”
Patients are kept in an isolation ward when their neutrophil count is less than 1,000/µ and kept in the intensive care unit when their platelets are less than 10,000/µ. Once these values normalize, the patients are ready to go home.
Allogeneic BMT—where stem cells are harvested from a genetically similar donor—is uncommon in veterinary medicine because no canine bone marrow registries exist and owners rarely know or have access to relatives of their pets.
The apheresis machine costs between $60,000 and $80,000 and the procedure comes with a $15,000 price tag, making the procedure costly to both the practitioner and client.
Dr. Suter wants to educate owners and veterinarians about the viability of the procedure. If performed more frequently, its expense could eventually be reduced.
Dr. Suter continues to modify the protocol in hopes of both decreasing expenses and increasing the cure rate. He plans to publish his results as they are finalized.
–Reprinted from Veterinary Practice News
Posted Dec. 5, 2011