HEMANGIOSARCOMA

What is hemangiosarcoma?

Hemangiosarcoma is a highly malignant cancer derived from endothelial cells, the cells which line blood vessels. Hemangiosarcoma tends to form tumors that have blood filled spaces and can rupture and bleed. The most common location for hemangiosarcoma in dogs is the spleen; however it can occur in many locations, including the heart, skin, and subcutaneous tissues.

How can we know if the cancer has spread?

Tests that determine if there is evidence of cancer in other locations include chest x-rays, to look for lung metastasis, abdominal ultrasound, and ultrasound of the heart. Even if these tests are negative, microscopic metastasis is likely to have occurred at the time of diagnosis, since hemangiosarcoma is a highly malignant cancer.

What are the treatment options? What is the prognosis?

1. No treatment:

With no treatment, hemangiosarcoma is a life-threatening disease, because the tumors can rupture and bleed.

2. Surgery alone:

With hemangiosarcomas of the spleen, surgical removal alone will result in survival times of about 4 months.

3. Surgery followed by chemotherapy:

With surgery (spleen removal) followed by chemotherapy, survival times are about 6-9 months. Hemangiosarcoma is not considered to be curable.

What chemotherapy drugs are used to treat hemangiosarcoma? How is it given? What are the side effects?

The most common chemotherapy drug used for hemangiosarcoma is Doxorubicin, or Adriamycin. It is given as a slow IV injection, once every 21 days, for 5 total doses. Side effects are uncommon but include bone marrow suppression, stomach and intestinal upset, allergic reactions, cardiomyopathy (can occur after >6 doses), and tissue damage if the drug leaks out of the vein during administration.

What can I expect as the cancer progresses and metastasizes?

Since hemangiosarcoma is a cancer that can metastasize (spread) to many different locations, the outcome depends largely on the area of the body most affected. If there is liver metastasis following a spleen removal, for example, then bleeding into the abdomen resulting in collapse and shock are possible. If there is metastasis to the lungs, labored breathing or coughing could develop. Often, progressive cancer results in weight loss despite a normal appetite.

Following completion of chemotherapy, reevaluation including chest x-rays and abdominal ultrasound is recommended periodically (usually every 2-3 months), in order to detect any progression of disease early. This would allow us to be as proactive as possible in either further treating with chemotherapy or in making your pet as comfortable as possible.