Lymphoma is one of the most common cancers in cats. It originates from a mutation and proliferation of a type of white blood cell called a lymphocyte. By the time of diagnosis, this cancer typically affects multiple different areas of the body at once. For this reason, it is not often a disease that is treated with surgery. Rather, we use chemotherapy to manage this cancer.
Chemotherapy is administered with the primary goal of fighting cancer while maintaining a very good quality of life for the pet. Our drugs are dosed with this goal in mind.
Unfortunately FeLV positive cats have a 60-fold greater chance of developing cancer than cats without the disease and approximately 25% of FeLV positive cats will develop lymphoma.
Diagnosing high-grade, lymphoma is often made with a fine-needle aspirate and cytology. This involves passing a small needle into your pet’s cancer and pulling back a small amount of cells and evaluating them under the microscope. Although this will not give us a definitive diagnosis, in the vast majority of cases this procedure will provide us with a very high suspicion of lymphoma. Once we have this sample, we can send it out to an outside lab for molecular diagnostics to more definitively diagnose your cat’s lymphoma and it’s type.
In certain forms, a surgical biopsy may be the only way to obtain a diagnosis.
Treatment and Prognosis:
The treatment of choice for most cats diagnosed with high-grade lymphoma is a multi-agent chemotherapy protocol, which takes advantage of 4 drugs, vincristine, cyclophosphamide, doxorubicin and prednisone. Deviations from the initial treatment plan are possible since it is tailored for the individual pet to prevent chemotherapy-related side effects while still being as efficacious as possible against the cancer.
With chemotherapy, approximately 60% of cats go into a complete clinical remission (meaning that no evidence of cancer is present on evaluation) and the average survival time is 6 months. This is an average number, meaning that 50% of cats will live longer while others will decline more quickly. We hope that with drug treatment, we will be able to help your pet live longer with a very good quality of life.
Less intensive and less expensive treatment options are available. Although cats still experience a good quality of life, survival times obtained with these protocols may not be as long as with the multi-agent protocol.
Finally, if chemotherapy is not used to treat your cat’s lymphoma, we can use a steroid called prednisolone or methylprednisolone to manage the disease. Steroids have anti-cancer effects and can help your cat feel better for some period of time. Typically, the survival time for cats with lymphoma receiving prednisone alone is 1-3 months. The response from steroids is difficult to predict with some cats’ lymphoma not responding while other cats can live as long as 6 months with steroids alone.
Because lymphoma tends to be a quickly progressive cancer, if left untreated the expected survival time is approximately 4-6 weeks.