The Dog Cancer Survival Guide (104 page)

“While going through the experience of splenic hemangiosarcoma with my golden doodle Ellie, I sometimes felt overwhelmed with anger and sadness. I also felt uncomfortable about crying a lot in front of Ellie. Needing a safe place to vent my feelings led me to make a special connection with a song. I would get in my car, start to drive, put on the song and just let my emotions go. Sometimes I’d end up crying so hard I’d have to pull-over, but I always felt so much relief afterward. Having a safe place to release my emotional pain was a huge part of taking care of me so I could better take care of Ellie.”

-
Sarah N. Bertsch, Hudson, Wisconsin

Metastatic lung lesions can often be seen on chest X-rays, although CT scans are more sensitive and show smaller lesions more easily. The heart may appear round (called globoid) on chest X-rays; this appearance suggests bleeding into the pericardial fluid. X-rays rarely show the heart masses themselves, however, so whether the heart is globoid or normal, it is helpful to get an echocardiogram to rule out a heart mass. Not everyone agrees that dogs with splenic masses also get echocardiograms to look for spread to the heart; I mention it because one study determined that one out of four dogs with spleen HSA had a concurrent heart tumor.

Dogs suspected for heart HSA should have both chest imaging (X-ray or CT scan) and abdominal ultrasounds to look for metastasis.

During the initial spleen removal, every lesion found in the abdomen suspected to be metastatic should be biopsied, and the liver will routinely be biopsied, even if its appearance is normal.

Even though not every oncologist agrees with me about this, I feel strongly that relying on an ultrasound to diagnose liver metastasis is a mistake. The liver is a rapidly regenerating organ, and we often see nodules – which are associated with rebuilding tissue – and mistake them for metastasis, even at surgery. Although dangerous to misinterpret an ultrasound in this way, it happens, especially with HSA cases. If a radiologist or vet thinks liver lesions are metastatic based solely on their appearance at surgery or on an ultrasound, ask for a biopsy to confirm the suspicion. I have seen many owners decide against surgery or even euthanize their dogs on the spot because they have been told (mistakenly) that HSA has already spread to the liver. Conversely, a liver that appears normal on ultrasound may still have metastasis, so it, too, should be biopsied.

In addition to imaging tests, a complete exam for HSA includes blood work – a complete blood count (CBC), chemistry panel, urinalysis and clotting profile are the bare minimum. When an abnormal heart rhythm is detected, an electrocardiogram should be run.

In addition to the aspirate used to confirm skin HSA, dogs with skin masses should have nearby lymph nodes aspirated to check for metastasis, plus chest images and abdominal ultrasounds to check for spread. They should also be carefully examined for masses, since skin HSA tends to spread to other areas of the skin.

Your vet may want to check the levels of vascular endothelial growth factor (VEGF), which is associated with cell division and the growth of new blood vessels (angiogenesis). VEGF can play a major role in tumor growth in humans, and for some cancers, its levels in the blood can help us understand whether the disease is very advanced, how it will progress and how it is likely to respond to therapy. A study of VEGF in dogs shows that while VEGF levels were higher in dogs with HSA, the levels couldn’t tell us the stage of the cancer, whether it would respond to treatment, or how long the dog would live. For these reasons, VEGF levels are probably not useful to confirm HSA or formulate a treatment plan in dogs. This is also why it is not used as an early detection or screening test, and is not routinely run in most veterinary hospitals. Knowing your dog’s VEGF levels might be helpful for your case and your vet may be able to get them from a specialized lab.

HSA is a fast-moving, aggressive cancer (half the number of afflicted dogs have already metastasized at the time of diagnosis). This is a tough disease for both oncologists and owners, because it is rarely caught early.

Here is the World Health Organization’s staging system for hemangiosarcoma:

Visceral HSa

Stage I:
A tumor smaller than 5 centimeter, confined to the primary site, with no regional or distant metastasis.

Stage II:
A tumor greater than 5 centimeter or a ruptured tumor, or smaller than 5 centimeter with confined regional metastasis, but no distant metastasis.

Stage III:
A tumor greater than 5 centimeter or a ruptured tumor, or a tumor that has invaded adjacent structures, with or without lymph node metastasis or distant metastasis.

Skin HSA

Stage I:
A tumor confined to the skin.

Stage II:
A tumor that involves the hypodermis or subcutis (the layers underneath the skin).

Stage III:
A tumor with muscle involvement.

Dogs who do not receive any treatment for their visceral HSA have a very short life expectancy (days to weeks).

Dogs who receive surgery alone for their splenic HSA have a median survival time of one to three months, and those receiving both surgery and post-operative chemotherapy (see the treatment section, below) have median survival times of six months. A stage I (the spleen has not ruptured) prognosis improves by a few months when treated with chemotherapy after surgery.

Dogs with heart HSA who have the mass removed and get follow-up chemotherapy have six-month median survival times.

Even with treatment, one-year survival times for splenic and heart HSA are uncommon – roughly ten percent.

Dogs with stage I skin HSA fare better: they have a median survival time of twenty-six months (over two years); dogs with stage II and III skin HSA (subcutaneous and muscle tumors) have median survival times of six to ten months. According to one recent study, dogs with subcutaneous HSA can experience median survival times over four years in length with aggressive surgery (wide, clean margins), with or without radiation therapy and with a chemotherapy protocol that uses doxorubicin.

The first treatment for HSA of any kind is surgery, followed by chemotherapy. Because so many dogs are unstable at the time of diagnosis – suffering from hemoabdomen or pericardial effusion – the very first priority is usually stabilization.

When the anemia is severe (from bleeding into the abdomen or pericardium), a blood transfusion is often required to make your dog stable enough for anesthesia. A clotting test should be run and fresh frozen plasma may be needed to further stabilize a dog with clotting abnormalities.

Once your dog is stable, the goal of surgery for visceral HSA is to remove the tumor and prevent or minimize future bleeding episodes. This nearly always requires a complete removal of the spleen. About 25% of dogs develop temporary abnormal heart rhythms following a splenectomy, so an ECG should be used to monitor the heart during and after surgery. While heart arrhythmias occasionally require drugs to manage, most resolve within days.

When your dog has pericardial effusion, the fluid is usually removed or “tapped” in a procedure called pericardiocentesis, relieving pressure on the heart. Sometimes this procedure only increases comfort temporarily, because fluid can re-accumulate within a day or week without additional therapy. Once the excess fluid is removed and your dog is stabilized, a heart operation can be considered.

The conventional treatments Dr. Ettinger recommends for hemangiosarcoma 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
.

The first option is to remove part of the pericardium – the sac around the heart – to allow fluid to accumulate in the chest, around the lungs. Even though fluid around the lungs can cause difficulty in breathing, that space can hold more fluid than the pericardium, and this gives the heart more room to function properly for longer. This procedure is considered palliative.

The second option is to remove the heart mass itself, which has been shown to increase median survival times to one to four months (similar to the median survival times for other visceral surgeries). This option is out of reach for some owners, because it requires an experienced heart surgeon and twenty-four hour intensive care after surgery. It also has a relatively high mortality rate – about fifteen percent of dogs undergoing this procedure die during surgery or during hospitalization afterwards.