Feline Lymphoma, Part 2

It is now three and a half years since my beloved Siamese, Polar, was diagnosed with renal lymphoma. After 15 months of treatments, countless trips back and forth from Long Island to the University of Pennsylvania Veterinary Hospital in Philadelphia, endless ultrasounds and follow-up visits, my warrior boy was declared not just in remission, but miraculously "cured."

- Elizabeth Jennings

"I think at this point, you can consider him cured," said Dr. Pascale Salah, DVM, DACVIM (oncology). Dr. Salah is the Oncology department head and Associate Professor of Clinical Medical Oncology at the University of Pennsylvania Veterinary School. "If anything else comes up after this, I think you could consider it unrelated," he continued. Dr. Salah also pointed out that Polar was one of only three cats in Penn Vet history to make it through the treatment protocol for renal lymphoma and be in remission.

While Polar proved an exception in this very serious case, there are many success stories in less serious types of lymphoma.

Is lymphoma more or less treatable than other cancers in cats?

"There are several types of lymphoma that can occur in cats, and they can have very different behaviors," said Dr. Katherine Skorupski, DVM, DACVIM (oncology). She is Chief of Medical Oncology and Professor of Clinical Medical Oncology at the University of California, Davis. "Lymphoma can be high-grade or low-grade, and grade predicts the behavior of the cancer. This includes the speed at which the cancer grows."

Skorupski further explained that high-grade lymphoma can occur anywhere in the body, often affects many organs at once, and usually grows quickly. In the case of Polar, who was diagnosed with a large tumor on his kidney (renal lymphoma), the oncologists at the University of Pennsylvania Veterinary Hospital felt the tumor had only been there for an estimated two weeks. In other words, very fast-growing.

"Compared to other cancer in cats and to high-grade lymphoma in dogs, response rates with chemotherapy are lower and survival is not as good (for high-grade lymphoma)," said Skorupski. "Lowgrade (also called small-cell) lymphoma is a slower-moving form of lymphoma that most commonly affects the intestines. Low-grade lymphoma responds very well to oral chemotherapy, and cats usually live many years after diagnosis."