Goals of Treating Brain Tumors
Obviously, treatment of any brain tumor must be specifically tailored to the type of tumor, whether it is primary or secondary, its location, and the extent of its invasion into surrounding brain tissue. The primary goals of treating brain tumors are to manage the potential secondary side effects of increased pressure inside the brain/skull and to try to reduce or eliminate the tumor entirely. Three general therapeutic approaches are currently available to treat brain tumors in domestic dogs. These are surgery, chemotherapy and radiation.
Surgical removal of a brain tumor is no simple task. However, it probably is one of the most important initial considerations for owners and veterinarians to consider. Surgery can be used for a biopsy, for partial removal of the mass or, hopefully, for complete resection (removal) of the cancerous tissue. If the tumor in the brain is from metastasis from another location, a surgical “cure” is probably not possible by removing the mass in the brain. However, surgical excision can be used to debulk the tumor and obtain tissue for a laboratory definitive diagnosis of the tumor type.
Radiation therapy can be used alone or in combination with surgery and/or chemotherapy for both primary and secondary brain tumors. This is a very sophisticated procedure that requires a skilled veterinary oncologist (cancer specialist) and specialized veterinary technicians and facilities.
Chemotherapy basically is treatment with high-powered drugs designed to kill rapidly growing cells. Chemotherapy targets not only cancer cells, but also cells of the body that normally are rapidly growing or reproducing, such as cells of the intestinal lining and hair follicles. This is what accounts for many of the unpleasant side effects of chemotherapy, including nausea and hair loss, in both dogs and in people. Nonetheless, chemotherapy is an important part of cancer therapy considerations for owner of affected dogs. Unfortunately, most chemotherapeutic drugs do not cross what is called the “drug-brain barrier”, which means that the drugs may not enter the brain and/or the spinal cord and therefore may not have their intended effect. However, there are some chemotherapeutic agents that can help to reduce brain tumors.
Chronic treatment for dogs with brain tumors usually involves treatment for seizures. Drugs such as phenobarbital and other anticonvulsant medications may be prescribed by the attending veterinarian.
Certain oral or injectable medications that are not chemotherapeutic agents may also be used in conjunction with one or more of the above treatment protocols to support a dog in treatment for a brain tumor. These may include steroids to reduce inflammation and drugs to help control seizures.
There is no realistic way to generalize about what the prognosis may be for a dog that has one or more brain tumors. The outlook will depend upon the type of tumor, its size and location, and whether it is primary or secondary in nature. However, the prognosis is probably best if the mass in the brain can be removed or reduced, either through surgery, radiation and/or chemotherapy.