Words You Don't Want to Hear
By: Ashley Mitek
University of Illinois College of Veterinary Medicine
Osteosarcoma and lymphoma: two words you hope to never hear coming from your veterinarian. Osteosarcoma (bone cancer) and lymphoma (a disorder of white blood cells) are the most common types of cancer in dogs. But thanks to the efforts of two veterinary oncologists at the University of Illinois, Veterinary Teaching Hospital in Urbana, these evil enemies of our four legged family members have a tough battle ahead.
As cancer cells are rapidly attacking, Dr. Timothy Fan, an assistant professor, and Dr. Laura Garrett, a clinical assistant professor, are working hard at the University of Illinois College of Veterinary Medicine to investigate novel treatment options and stay one step ahead of our pet's arch rivals. "The positive aspect of this situation is that these common cancers, especially lymphoma, are very responsive to systemic chemotherapy treatment, but as time progresses surviving cancer cells inevitably become resistant to our traditional therapies, and we hit a brick wall," says Dr. Fan.
Dr. Garrett is leading a clinical research trial with canine lymphoma. She is currently working with Dr. Paul Hergenrother in the University of Illinois Department of Chemistry to test the safety and effectiveness of a revolutionary small molecule that possesses the capacity to preferentially cause tumor cells to die. Dr. Fan's research focuses on the treatment of osteosarcoma. He is collaborating with Dr. Jianjun Cheng, a researcher from the Department of Material Sciences and Engineering to evaluate the clinical usefulness of a very small bead (using nanotechnology) that holds chemotherapy drugs that specifically target the bone microenvironment in which cancer cells grow.
According to Dr. Fan, osteosarcoma is usually seen in dogs older than seven, and the disease has a higher incidence in certain breeds, such as rottweilers. "It is important to treat the disease as soon as you observe it to help maintain a reasonable quality of life," says Dr. Fan. The typical symptoms of a dog with bone cancer are sudden onset of lameness that becomes extremely painful. Radiographs, or x-rays, are performed to support a diagnosis, but the only way to confirm ostesarcoma is with a biopsy, or aspirate of the tumor.
There are two general treatment plans for bone cancer: pain management, or the best the veterinary profession can offer at this point -- amputation and chemotherapy. According to Dr. Fan, pain management alone will not stop the growth of the tumor, nor prevent it from spreading to other parts of the body. But it will give your pet approximately another 4-6 months of quality life.
The other option, amputation of the affected limb, followed by systemic chemotherapy, buys you a bit more time. "Fifty percent of dogs who undergo this treatment will live a year, and twenty percent live two years," says Dr. Fan.
It is important to note that although this therapy will not be inexpensive, animals tolerate chemotherapy much better than humans because the dose given is significantly less. Only a minority of animals experience adverse side effects, mentions Dr. Fan.
Despite the best efforts of researchers across the country, treatment of cancer in animals has still not caught up with humans. The biggest impediment is finances because most families opt not to carry health insurance for their pets.
Secondly, there are a very limited number of clinics in the country with the infrastructure to treat dogs aggressively. Because of researchers like Drs. Fan and Garrett, there is hope that the thousands of dogs diagnosed with osteosarcoma or lymphoma may live a longer and better life.
For more information about cancer in pets, contact your local veterinarian.