Cancer 101: Common Questions Answered

Medical articles
Pet Cancer Questions

Q: My vet said my dog has a tumor that he is going to do some testing on. Does this mean my pet has cancer?

A: A tumor is any sort of lump, bump, growth, or swelling; it is a very broad term that veterinarians use, and I understand it can sound alarming. This does not necessarily mean that the “tumor” is cancer, but it can be used to describe cancerous growths as well. Always ask for clarification because his use of the word “tumor” can be tricky to decipher.

Q: My vet said that the tumor turned out to be neoplasia, but it wasn’t a harmful type. I thought all cancer was bad?

A: Tumors that are cancerous are called neoplasms and can be divided into two broad categories: benign and malignant.

Benign tumors grow slowly, don’t invade or destroy neighboring tissue, and don’t spread to other parts of the body. These cancers aren’t usually life threatening. They are cured by surgical removal, provided that the entire tumor can be removed.

Malignant tumors are potentially life-threatening cancers. Malignant neoplasms invade neighboring tissue and continue to grow, often destroying healthy tissue. For many malignant tumors, malignant cells leave from the original tumor and enter the lymphatic system or the circulatory system, establishing new neoplasia in other areas. This process is called metastasizing.

Q: What is the difference between a primary and secondary cancer?

A: Cancers are named and classified further upon where they began. The primary cancer is where the cancer started. If some of the cancer cells break away from the primary cancer and settle in another part of the body, this cancer is then called a secondary cancer. Secondary cancers are made up of the same type of cells as the primary cancer. So, if your dog has bone cancer that has spread to the lungs, your dog has primary bone cancer with secondary bone cancer in the lungs.

This is important because veterinarians choose treatment according to the type of primary cancer. The cancer cells in the lungs are actually bone cancer cells, not primary lung cancer.

Q: My vet wants to stage my pet’s cancer? If we know what type of cancer it is, why can’t we just go ahead and treat it?

A: Staging information is crucial for several reasons including determination of your pet’s expected outcome against the disease (prognosis) and development of an appropriate treatment plan.

To gather information that can help to determine the extent of the cancer, your veterinarian will need to evaluate your pet by several methods. These may include blood and urine tests, radiographs (x-rays), fine needle tissue aspirate (a small sample taken with a fine needle), and a larger tissue examination called a biopsy. In addition, other testing procedures may include: ultrasound, specialized radiologic studies (such as a CT scan), bone marrow aspirate, lymph node aspirate, and other advanced diagnostic procedures.

Once the tumor staging is complete, your veterinarian will better be able to accurately discuss treatment options and their pros and cons for your pet.

Q: What treatments are available for pet cancer today?

A: Cancer treatment in pets has come a long way. Our main options are surgery, radiation therapy, and chemotherapy. Some hospitals and institutes are even doing research and clinical treatment of patients with immunotherapy tumor vaccines. Cancer treatment options for pets have advanced tremendously in the past two decades.

Q: Will my veterinarian treat my pet’s cancer or will I need a specialist?

A: Your veterinarian may refer you to a veterinary oncologist who specializes in pet cancer. Commonly occurring pet cancers may be treated effectively at your local veterinary hospital. Chemotherapy and surgery are rather commonplace; it is radiation therapy and immunotherapy that often require seeking out special teams and facilities.