In dogs with hemangiosarcoma, treatment with a compound originating from the Coriolus versicolor mushroom was shown to result in survival times longer than any recorded so far in dogs with this condition.

Hemangiosarcoma is an aggressive form of cancer with a high metastatic rate that originates in endothelial cells that line blood vessels. This tumor is not uncommon in dogs, and typically arises in the spleen of middle-aged to older animals, and is associated with rapid and widespread metastases. Although it can affect any breed, German shepherd dogs and golden retrievers are particularly predisposed to this fatal disease.

But could there be hope?

Coriolus versicolor, more commonly known as the Yunzhi mushroom, has been used in traditional Chinese medicine for more than 2,000 years. It contains polysaccharopeptide (PSP), a compound that is thought to have immune-stimulating properties, and has more recently been suggested to also have an anti-tumor effect.

Some interesting data recently emerged from a study out of the University of Pennsylvania School of Veterinary Medicine. Single Agent Polysaccharopeptide Delays Metastases and Improves Survival in Naturally Occurring Hemangiosarcoma (Brown DC and Reetz J. Evidence-Based Complementary and Alternative Medicine. Vol 2012 (2012); Article ID 384301) reported results from a double-blind, multi-dose pilot study designed to evaluate the effect of PSP treatment on survival time in dogs with hemangiosarcoma.

It included 15 dogs with the disease that were randomized equally across 3 treatment groups Each group was treated daily with a different dose of a manufactured formulation of PSP (25, 50, or 100 mg/kg/day). Dogs were examined monthly for disease progression.

The results of the study demonstrated that high-dose PSP significantly delayed the development of metastatic hemangiosarcoma, leading to the longest survival times reported in the veterinary literature in dogs with this tumor.

Previously, the longest median survival time reported in the veterinary literature in cases of splenic hemangiosarcoma, in dogs that did not undergo treatment, was 86 days. Although survival times were not significantly different between the dosage groups, the median time to development or progression of abdominal metastases was significantly delayed in the 100 mg/kg/day group (112 days; range 30-308 days), and the highest median survival time was 199 days. Some dogs in the study lived longer than a year.

Splenic hemangiosarcoma often remains undiagnosed until the tumor ruptures, leading to emergency presentation of the dog due to shock. At this stage, many owners choose surgical removal of the spleen rather than immediate euthanasia, despite the poor prognosis. But even if not evident at the time of surgery, widespread metastasis occurs rapidly, typically leading to fatal hemorrhagic crisis within about 3 months of the initial surgery.

Some owners consequently also opt for adjuvant chemotherapy with single agent and combination doxorubicin-based regimens. Although median survival times of 141-179 days are reported in dogs that have undergone surgery plus chemotherapy, this does not increase in the 12-month survival rate above that associated with surgery alone.

Although further investigation of this compound and its effect on survival time is warranted in dogs with hemangiosarcoma, results of this pilot study suggest that PSP may offer hope for use as a treatment alternative or addition to chemotherapeutic regimens.


Image credit taliesin @morgueFile