How is Cancer Treated?
Each type of cancer requires individual care and may include a combination of treatment therapies such as surgery, chemotherapy, radiation, cryosurgery (freezing), hyperthermia (heating) or immunotherapy. Once you have a diagnosis, your veterinarian will discuss the best treatment option(s) for your pet. In some instances, your veterinarian may refer you to a board-certified oncologist (cancer specialist) depending upon the recommended course of treatment.
What is chemotherapy?
Chemotherapy simply means treating disease with medication. The term is most commonly used to refer to treating cancer with medication. Most chemotherapy drugs are given directly into a vein, but others are given orally or by injection into a muscle. Chemotherapy alone is effective against some forms of cancer such as lymphoma, but is often used in combination with other treatments such as surgery. The side effects seen in veterinary chemotherapy, although not entirely absent, are usually significantly less severe than those seen in human medicine because lower dosages of medication are often used. The side effects vary for each drug and for each dosage used.
What is radiation therapy?
Radiation therapy is one method of treating cancer with Xrays or electron radiation. It may be used alone, or in conjunction with other treatments such as surgery, chemotherapy or local hyperthermia (heat). The effectiveness of radiation therapy varies depending on the size of the tumor, the species of the patient, the type of cancer it is, and where the tumor is located. It is most effective at treating tumors that occur in one area (localized disease) rather than tumors that have spread to other parts of the body (systemic disease). Radiation therapy is ideally given every day for a period of three to four weeks, and each treatment requires a brief general anesthesia. The side effects of this treatment vary depending on what part of the body is treated.
What is cryosurgery?
Cryosurgery is a method of killing tumor cells with extreme cold temperatures using liquid nitrogen. The tumors best treated with cryosurgery are small, benign masses less than one inch in diameter. Typically, these masses are located on the eyelid, anus, mouth, or skin. Depending on the location of the tumor, the patient may require sedation, local anesthesia, or general anesthesia to perform cryosurgery.
How is surgery used to treat cancer?
Surgery can be used to remove tumors completely or to "debulk" them to make other modes of therapy more effective. Surgery is also used to obtain biopsy samples to help identify the type of cancer your pet may have. The extent of surgery (or surgical dose) varies depending on the goals for each individual patient, as well as the grade and stage of the disease.
What is hyperthermia?
Hyperthermia is a method of treating solid tumors using heating devices to raise the temperature of a tumor. Since tumor cells are very sensitive to increased temperatures, raising the temperature kills tumor cells. Protecting normal tissue is very important, so the type of heating device depends on the location of the tumor. Hyperthermia is often combined with other cancer treatments such as radiation therapy or chemotherapy. In combination, they work synergistically to kill additional tumor cells.
Hyperthermia is currently available for the treatment of pets with cancer at a limited number of veterinary teaching hospitals. Studies are ongoing to determine how to uniformly heat a variety of tumor types, and to determine the optimal dose of hyperthermia.
From Colorado State College of Veterinary Medicine and Biomedical Sciences