Goals of Treating HAS
The main goals of treating hemangiosarcoma are to remove the tumors surgically if possible, minimize the chances of bleeding from tumor rupture and prolong the dog’s survival time and quality of life.
If the cancer has spread to the spleen, that organ can be removed by a splenectomy. Unfortunately, depending upon the extent of local invasion of the cancer into surrounding areas, it is not always possible to remove all of the cancerous tissue. Radiation, chemotherapy and medically-induced elevation of body temperature (“managed hyperthermia”) are other available techniques that can be used to treat – or at least to manage - hemangiosarcoma. While these techniques may help to prolong a dog’s life, they almost never accomplish a complete cure. This is true even if the tumors are removed before there is any detectable evidence that the cancer has spread.
Chemotherapy involves administering highly toxic drugs directly into a dog’s bloodstream through a vein (intravenously). These drugs target and kill rapidly-dividing cells, such as cancer cells. Unfortunately, current chemotherapeutic drugs cannot distinguish between cancer cells and other cells that normally reproduce rapidly, like cells that line the inside of the stomach, intestines and hair follicles. As a result, chemotherapy carries the risk of severe side effects, including nausea, weakness, hair loss, and perhaps even death.
A dog diagnosed with hemangiosarcoma deserves nurturing and kind supportive care, whether or not surgery, chemotherapy or other treatments are attempted. This might include administration of intravenous fluids to keep the dog well-hydrated. Blood transfusions, corticosteroid medications and/or antibiotics may be appropriate, depending upon the particular dog’s condition. Of course, a clean, warm, safe living environment, a high-quality diet and free access to fresh water are always important to a dog’s comfort and overall well-being.
The prognosis for dogs with hemangiosarcoma is highly variable. It depends upon how advanced the cancer is, and when treatment begins. In most cases, the ultimate outcome is guarded to grave, especially when the tumors are internal (noncutaneous hemangiosarcoma). Dogs with internal hemangiosarcoma usually die within a few months after their disease is diagnosed. Survival longer than one year is extremely rare. Dogs with hemangiosarcoma of the skin (cutaneous), or layers just below the skin (subcutaneous), are less likely to have the cancer metastasize to other areas. Therefore, they have a much better chance of going into remission following surgical removal of their tumors.