The Dog Cancer Survival Guide (114 page)

Confirmation of a brain tumor requires advanced brain imaging, preferably MRI (magnetic resonance imaging). MRIs are better for showing detail in soft tissues and highlighting subtle changes, making them ideal for brain scans. Computer tomography (CT) scans are adequate for brain tumors, and better for bone tumors that are compressing the brain from the skull. While CT is typically a little cheaper, both are expensive relative to X-rays. They also require anesthesia and a specialty hospital.

After the MRI (or CT) scans, your vet or oncologist may want to do a cerebrospinal fluid (CSF) tap. In this test, a needle is inserted into the spinal cord and the fluid that lubricates and cushions the brain and spinal cord, is drawn out to be examined. This test requires anesthesia, so it is usually scheduled immediately after the MRI, while your dog is still under.

Cancer cells are not usually detected in cerebrospinal fluid, even when cancer is present, but looking at it can help your oncologist to rule out other possible causes of your dog’s symptoms, for example, an inflammatory condition. A study which measured the usefulness of the CSF tap found that 40% of the samples collected had protein and white blood cell counts that supported a diagnosis of cancer, 10% had completely normal fluid, and 50% had non-specific changes. If there is any doubt about your dog’s diagnosis, this test may help.

In any other cancer, a biopsy would be necessary to confirm the diagnosis; brain cancer is very different. Biopsies are not usually done, because many tumors are just not accessible, and the expensive procedure is too risky. Unfortunately, without a confirmed diagnosis of the type of tumor, it is very difficult to make an accurate prognosis for your dog. If your vet or oncologist will not give you a specific prognosis, this is likely the reason.

Even though it is rare that brain cancer spreads to other organs, the rest of the body should still be checked for cancer, because meningioma has been reported to spread to the lungs and pancreas. It’s also possible that the brain tumor is not a primary tumor, but a metastasis from another primary cancer, somewhere else in the body. In that case, treatment recommendations are likely to be very different than those for a primary brain cancer.

Staging tests I recommend include: blood work, urinalysis, chest imaging, such as three-view thoracic X-rays and abdominal imaging, typically ultrasound. These tests do not require anesthesia, so they are typically performed before a CT scan or MRI, which do.

It is nearly impossible to give a specific prognosis for any given brain tumor, since so few offer reliable information from a biopsy. However, if left untreated, survival times usually range from one week to two months. If surgery, radiation and chemotherapy combinations outlined below are declined, palliative support can be given, using steroids and anticonvulsant medications. Some dogs show dramatic improvement on steroids alone, gaining weeks or months of life; adding anti-convulsant medications can extend survival times two to four months.

Because we so rarely know with certainty what type of tumor we’re dealing with, brain tumors are often considered collectively for treatment and prognosis. The goals of treatment are to remove the tumor when possible, reduce the tumor’s size and relieve the symptoms associated with the tumor: swelling and inflammation.

If possible, the tumor may be surgically removed or debulked (reduced in size). Whether this is possible or not will depend upon the location, size, invasiveness and extent of the tumor in question, so a good MRI scan is essential to plan the surgery. With recent advancements in surgical techniques, anesthesia and critical care, brain surgery is an option more and more often. Even a simple debulking of the mass can provide significant relief from the pressure and symptoms.

An advantage of surgery is that the tumor can be submitted for a biopsy, which will lead to a confirmed diagnosis and more information about the illness. Clearly, brain surgery requires an experienced and confident surgeon, typically a neurosurgeon. Intensive care and monitoring after surgery are also necessary. The median survival time for dogs with surgically removed brain tumors is seven to eight months, with a range of six to twenty-two months. Neurosurgeons can be found by using the “find a specialist” tool at
www.AVCIM.org
. Search for neurologist, but check to see if they do brain surgery – the hospital should be able to confirm this before you book an appointment.

If a surgery is incomplete, traditional radiation may be used as a follow-up treatment. When used as an adjunct to surgery, radiation increases median survival times to about sixteen months, for all brain tumor types. Dogs with meningiomas can significantly extend their life expectancy, up to thirty months (two and a half years)!

The conventional treatments Dr. Ettinger recommends for brain tumors should be considered part of step one of Full Spectrum cancer care (
Chapter 11
). Please review that chapter for more general information about surgery, radiation and chemotherapy and how to handle their common side effects.

For more information on all other Full Spectrum steps, including nutraceuticals, immune boosters, dietary changes and brain chemistry modification strategies, review Full Spectrum cancer care, which begins on
page 103
.

You will also find information about specific chemotherapy agents in
Chapter 41
.

Radiation therapy can be helpful for dogs with inoperable tumors, as well. The median survival time for brain tumors treated with traditional linear accelerators is about ten months, with a range of five to fifteen months. Of course, with radiation therapy, there are typically many treatments (sometimes as many as fifteen), all of which require anesthesia. Radiation side effects include (extremely rare, life-threatening) brain swelling, herniating (swelling so much that part of it is pushed out of the base of the skull), and brain death.

Radiosurgery, which is much more precise and has far fewer side effects, is proving ideal for brain tumors. My hospital has had the CyberKnife radio-surgery machine since 2008, and we have used it to treat more brain tumors than any other type. Human cancers have been treated with this machine for years; we are one of the first hospitals to use it to treat animals. It is too early to fully evaluate all of the data, but preliminary results for brain tumors offer your dog a median survival time of about fifteen months. This is about the same result as with traditional radiation therapy; far fewer treatments are required (one to three), however, and the side effects are less likely (although they still occur). So far, no herniations have occurred in dogs treated with radiosurgery, neither at our center nor at a veterinary school that also performs this technique.

“... although everything seems so terrible and you’re confused and feel helpless you have to try and firstly stay strong for one another. You have to see beyond the word cancer and take positive action immediately. Little steps at a time as there is so much information out there. Do your research, change the diet immediately. Remain high spirited and joyful as soon as you can in front of your dog as they can not only sense your pain but have to deal with theirs too. Remember there is positive guidance and great vets out there. Nothing is impossible: where there is a will there’s a way! If it means trying everything then do, but make sure you spend your time researching the good not the bad. You’re the driving force behind your dog’s recovery. They need you just as you need them. It’s not the end, don’t settle for the C word – beat it as long as you can. At least you’ll live to know that you tried everything in your power.”

- Margherita Ferlita, Surrey, England