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Hemangiosarcomas
Dr.
Gail Mason, DVM, MA, DACVIM
Kathi
Smith, RVT, Internal Medicine & Oncology Technician
Hemangiosarcomas
(HSA) are highly aggressive malignancies
arising from the lining of blood vessels. These
tumors can arise anywhere in the body but most
frequently involve the spleen, heart, liver
and skin. About 25% of dogs with HSA have both
the spleen and heart involved. Tumor spread
occurs most often to the liver, mesentery, lungs,
and brain.
Symptoms
of HSA in animals are usually attributable to
the tendency for HSAÕs to hemorrhage. If internal
organs are involved, the patient may be weak/collapsing,
have pale gums, a rapid and shallow respiratory
rate and perhaps abdominal enlargement. Emergency
intervention (surgery and supportive care) is
critical to patient survival.
Patient
Evaluation
The
first step in treating veterinary patients for
HSA is to evaluate general patient health and
to assess the extent of the cancer (clinical
staging.) This step helps the clinician formulate
a treatment plan and allows more precise determination
of the prognosis. Evaluation may include the
following diagnostics:
• Complete blood count (CBC)
•
Serum chemistry panel (assess organ function)
• Urinalysis
• Coagulation profile
• Chest radiographs (x-rays) - evidence
of metastasis?
• Ultrasonography - (assess extent or spread
of HSA)
Staging
of HSA
The
prognosis for dogs with HSA is known to be affected
by the clinical stage of the disease. In general,
this refers to:
Stage I Ð Localized tumor; no other tumors seen
at the time of surgery
Stage II Ð A ruptured tumor which is confined
to the primary site, such as an HSA of the heart
or spleen. There may or may not be metastasis
present near the site of the primary tumor.
Stage III Ð A ruptured primary tumor with invasion
into adjacent structures plus local or distant
metastasis.
Teatment
of HSAÕs
Hemangiosarcomas
are, unfortunately, highly aggressive tumors
and virtually all patients will eventually die
from the disease. Currently, these tumors defy
cure in veterinary patients. However, a systemic
thrapeutic approach which involves, 1) surgical
resection of the primary tumor and 2) the addition
of chemotherapy, can provide a remission from
the cancer.
Drugs
used for HSA (post surgery)
1. Doxorubicin IV administration
2. Vincristine IV administration
3. Cyclophosphamide or Lomustine Oral administration
The
combination of drugs used may differ but the
most common treatment interval is about every
21 days. Most often, treatment is continued
for at least 6 months.
Prognosis
An
exact prognosis for a particular patient with
HSA is impossible to predict. However, over
fairly large numbers of treated animals published,
the following statistics are offered as guides:
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