Canine Osteosarcoma (OSA) is a type of aggressive bone cancer that most commonly affects the limb bones, especially the fore limbs of the middle aged and elderly dogs. The most common victims of this dog cancerare large dog breeds like Rottweilers, Shepherds, Labradors, Dobermans, Great Danes, Saint Bernards, Irish Wolfhounds and Golden Retrievers. The malignant or cancerous tumor develops deep within the bones, and then grows rapidly to destroy the bones from the inside. Osteosarcoma in dogs can also metastasize to other parts of the body, more commonly to the lungs and other bones of the skeletal system. The incidence of the disease has been found to be slightly higher in male dogs than their female counterpart. Though, the exact causes of the diseases are not known, it has been observed that the tumors generally develop in the growth plates. This led to the speculation that the cells of the growth plates have a genetic predisposition for the development of malignant tumors.
Symptoms of Osteosarcoma in Dogs
Osteosarcoma mostly affects the forelimbs of the dogs, that bear much of the body's weight. Sometimes, tumors can also develop in the skull and ribs, and spread to areas like the lungs. The most commonly observed symptoms of this condition are lameness, usually intermittent, but can gradually become permanent, with increased damage of the affected bone/ bones. In addition pronounced swelling of the affected bone and pain in the affected limb.
Osteosarcoma in Dogs –Current Treatment and Novel Clinical Studies
The most common treatment for OSA in dogs is amputation, followed by chemotherapy. Sometimes, limb sparing surgery is also carried out, if the tumor has not affected more than 50% of the bone, and also has not spread to the surrounding muscles.
Chemotherapy drugs often prove effective in altering the course of this bone cancer. Two new studies taking place at North Carolina State-College of Veterinary Medicine, under the direction of veterinary oncologist Dr. Laurel Williams, will evaluate if novel chemotherapeutic drugs developed for other forms of cancer, will help in the treatment of dogs with Osteosarcoma.
The first study is an evaluation of dogs with Osteosarcoma that have received an amputation and Palladia (assessing anti-angiogenic benefits). Patients recruited for this study must have a cytologic or histologic diagnosis of OSA, undergo amputation, and begin Palladia 5 days following surgery. Patients will be required to return to NCSU each month for bloodwork (to monitor Palladia and collect serum for biomarker evaluation); a recheck exam and thoracic radiographs will be performed at two-month intervals as would be done for any dog with OSA. The study covers the costs of Palladia and monthly bloodwork (CBC, chem, urinalysis). The client will be expected to pay for initial evaluation, amputation, and recheck visits with thoracic radiographs (as would be done for any dog with OSA) - in the research setting, the cost of the recheck visit / thor rads is appx $150.
The second study currently underway at NCSU-CVM is a taking place in collaboration with oncology investigators at Ohio State University(OSU). This study aims to evaluate dogs with OSA treated with amputation, carboplatin chemotherapy and one of two metronomic treatment protocols. This study is based out of OSU and we are a collaborating site. In this study, dogs undergo amputation followed by four cycles of carboplatin (drug provided at no cost to client). Clients also receive a stipend of approximately $50-75 per study visit towards associated lab tests.
Owners or veterinarians interested in either one of the two studies can contact study coordinator Julie Nettifee Osborne, RVT, BS at (919) 513-6812 or via email (.(JavaScript must be enabled to view this email address)) or Laurel Williams (.(JavaScript must be enabled to view this email address)).
