The word cancer strikes fear in all of us; however, with new advances in veterinary medicine, many pets are living longer, with a greatly improved quality of life.
Successful cancer treatment often lies in early detection. Yet early detection can be difficult as cancer may not only present itself as a lump on the skin but may develop internally. If this occurs, a thorough examination with diagnostic tests (x-rays, ultrasound, blood analysis) can often discover the tumor. If left undiagnosed, the disease may not be noticed until clinical symptoms develop.
Treatment also depends on the type and location of cancer. If possible, surgical removal of the tumor is recommended. Some types of cancer are responsive to chemotherapy, which includes a variety of oral and injectable drugs. Dogs and cats tend to tolerate chemotherapy well, rarely developing side effects.
What is Cancer?
Cancer is the unrestrained and unregulated growth of cells that occurs despite the body’s anti-cancer defense mechanisms or immune system. Cancer begins with a single cell that fails to respond to growth signals from the rest of the body. This cell can begin to grow for weeks, months or even years before being detected.
What Causes Cancer?
There are several potential causes of cancer, including tobacco smoke, certain nutrients, radiation, drugs, toxins, viruses, inflammation, pollution, chemicals or any other substance that can damage DNA. In the majority of animal cancers, it is often difficult to pinpoint a specific cause for the development of cancer. Some cancers are more common than others. Lymphoma in both dogs and cats is the most commonly treated cancer. In dogs, cutaneous Mast Cell cancer is the most common skin tumor that we see.
What is Chemotherapy?
Chemotherapy drugs are compounds that are toxic to cancer cells. Cancer cells generally multiply very rapidly. Most chemotherapy drugs work by damaging the ability of these rapidly growing cells to divide, eventually killing them. There are many different types of chemotherapy, including intravenously by injection or orally administered drugs. Some are given in the clinic intermittently and some are given at home on a long-term, continuous basis. A newer form of chemotherapy is targeted therapy. These are drugs that are generally given orally and block specific growth receptors on the tumor cells to inhibit their growth. Different chemotherapy drugs and protocols have different effectiveness again specific tumor types and are recommended based on this known or suspected efficacy.
What is Immunotherapy?
Immunotherapy is using the body’s own immune system or natural defenses against cancer cells. This is generally done by encouraging the body to make antibodies against the tumor cells (vaccine therapy) or by giving the antibodies directly (monoclonal antibody therapy). Immunotherapy can be used as the sole treatment or may be combined with chemotherapy or radiation.
What is Radiation Therapy?
Radiation therapy is the collective use of x-rays for treatment purposes. The most common way of delivering these x-rays is by using a linear accelerator (LINAC). A LINAC works by using microwave technology to accelerate electrons which collide with a heavy metal target. As a result of these collisions, high-energy x-rays are scattered from the target. A portion of these x-rays are collected and then shaped to form a beam that matches the patient’s tumor, which is based on a radiation oncologist prescribed treatment plan.