Janet Carreras, Gulf Coast Veterinary Specialists – www.mygcvs.com
With advances in veterinary medicine and overall pet care, the likelihood of eventually being faced with a diagnosis of cancer in a pet increases since our pets are living longer.
As with human patients, cancer can have variable behavior depending on the diagnosis. Some types of cancer are very treatable and many are curable. But early diagnosis can be critical. If you notice a mass or growth on your pet, or if you notice asymmetry when you compare two similar structures, ask your veterinarian to check it out right away. No one knows your pet better nor has their hands on them more often than you do, so let your veterinarian know of anything that you see that you have not seen before. If a bump has been present for a long time suddenly gets larger, that is a concern.
A diagnosis of cancer can be devastating, and the terms that your veterinarian uses can be confusing. Below is a little pocket-guide to some of the terms used frequently when talking about the diagnosis and treatment of cancer.
A fine needle aspirate (“needle biopsy”) is a simple procedure that a veterinarian can usually do without the need for sedation or anesthesia. A needle is inserted into a mass and cells are pulled back in to the needle using the suction from a syringe. The cells are pushed out onto a slide for analysis called cytology. This simple procedure takes only seconds to do and can often be the first step in early diagnosis of cancer. Your veterinarian may recommend submitting the slides for review by a pathologist if there is a concern for cancer.
If cytology does not yield an answer or is not possible, a biopsy may be recommended. A biopsy will usually require sedation or anesthesia as it is a type of surgery. An incisional biopsy is when a small piece of the mass is removed to help determine the diagnosis before the final treatment recommendation is made. If the entire mass is removed, this is called an excisional biopsy.
The biopsy sample is submitted to a pathologist for microscopic examination called histopathology. In the histopathology report, the pathologist describes the cellular characteristics and helps your veterinarian or veterinary oncologist understand how aggressive the biopsy sample is. Some tumors (growths) are benign (not cancerous). Some cancers are very locally invasive and have a high risk of recurring locally. Some cancers have a high risk of spreading to distant sites. By assessing individual tumor characteristics, the pathologist determines the tumor grade. Each type of cancer is graded using a different grading system. Your veterinarian and veterinary oncologist will consider the tumor grade and other factors when developing an individual treatment plan for a patient.
Cancer stage refers to the extent or severity of the cancer based on factors such as the location of the tumor, tumor size, number of tumors, and presence of cancer spread to distant sites including lymph node, lung, or other organs. Your veterinarian or veterinary oncologist may recommend diagnostics tests including lymph node cytology, chest x-rays, abdominal x-rays, abdominal ultrasound and/or other tests to help determine the stage of the cancer.
It is important to remember that every patient is individual and treatment options may differ based not only on the tumor diagnosis, grade and stage, but also the overall health of the pet and goals of the pet-owner. If you are faced with the diagnosis of cancer in your best friend, I strongly encourage you to seek the advice of a veterinary oncologist. Pet owners are often turned-off by the idea of surgery, chemotherapy, radiation therapy or other anti-cancer therapies for their pet because they worry that quality of life may suffer. Then they are surprised to learn that their veterinary oncologist may actually be able to improve quality of life for their pet using these techniques.