4 Promising Studies: Early Detection and Treatment Options for Canine Hemangiosarcoma

Hemangiosarcoma is a form of cancer found almost exclusively in dogs. A relatively common canine cancer (6-8% of all canine cancers) it is estimated that 2 million of 73 million dogs currently alive in the United States will develop the disease and die from it. At this time, it is considered incurable, as it remains symptomless until the advanced stages of the disease.  The current standard of care, surgery and chemotherapy, have proven to extend the life to the affected dog a mere median of 180 days with surgery alone, and an additionally 180 days with chemotherapy added to surgical intervention.  In the wake of these poor treatment outcomes, research has focused on earlydetection of the disease as well as a very promising alternative medicine approach.

Hemangiosarcoma is an indolent cancer, meaning it initially develops very slowly, asymptomatically and painlessly.  The most common primary sites of the disease are the spleen, right atrium of the heart and the tissue beneath the skin.  In the later stages of the disease, the cancer aggressively metastasizes to the lungs, liver and intestines.   While dogs of any age and breed may be susceptible to hemangiosarcoma, it occurs more commonly in dogs beyond middle age, and has a higher incidence in breeds such as German Shepherd Dogs, Golden Retrievers, Portuguese Water Dogs and Skye Terriers, suggesting a genetic component is involved.

The completion of the Canine Genome Project has spurred research into the genetic components of a wide variety of physical ailments believed to have heritable factors. Researchers at Modiano Lab at the University of Minnesota have taken an interest in the genetic components contributing to hemangiosarcoma.   Three of the more promising approaches involve mapping the risk alleles associated with the disease, determining the genetic, breed-specific abnormalities of the tumors themselves and developing a blood test for early detection of cancer cells via flow cytology.

The first project, developed in collaboration with Dr. Matthew Breen, focused on the possibility of breed specific abnormalities that may be detectable in tumors arising in dogs of different breeds. The initial results were promising; the data showed that tumors from dogs of one specific breed are functionally and genetically more similar to each other than they are to tumors from dogs of other breeds. This information demonstrates that heritable risk factors contribute to the development of canine cancer. More importantly, these results are the first step toward developing prevention and treatment strategies that address the specific causes underlying the biology of canine hemangiosarcoma.

The second project of great promise, developed in collaboration with the National Human Genome Research Institute of the National Institutes of Health and the Broad Institute of MIT and Harvard, has begun the process of mapping the risk alleles for the development of both Lymphoma and Hemangiosarcoma in the following target breeds:

Australian Shepherd

Bernese Mountain Dog

Border Collie

Boxer

Briard

Bullmastiff

Cocker Spaniel

Flat-coated Retriever

German Shepherd Dog

Golden Retriever

Greyhound

Irish Setter

Keeshond

Labrador Retriever

Mastiff

Poodle

Portuguese Water Dog

Rottweiler

Vizsla

Saluki

Researchers are currently seeking samples for this research in the form of blood samples and tumor samples with associated pedigree information.  Samples from mixed breeds and other breeds are welcome from both healthy (aged) dogs and affected dogs.  To learn more about how to contribute to the project visit http://www.modianolab.org/studyInfo/studyInfo_index.shtml.

Once we have a genetic test that can forewarn us of a genetic predisposition to developing specific cancers, we will want to be able to detect the disease at an early stage of its development, well before it becomes symptomatic.

As cancer tumors grow, they shed cells into the blood stream.  However, the tumor cells are shed so infrequently that they cannot be detected in routine blood tests. Enter the technology called flow cytometry. Here cells are “tagged” with fluorescent molecules that identify their lineage of origin, they are then run through an instrument (the flow cytometer) that combines optics and fluidics information through a software capable of analyzing hundreds of thousands of cells in a matter of minutes. Researchers have employed this technology and have successfully shown proof of principle for this test. Idexx Laboratories has licensed the technology from the University of Colorado, although the ultimate affordability of employing this technology in local veterinary practices tests remains to be seen.  Another issue with this technology, is that it does not tell us where the site of origin of the tumor is. Early treatment will therefore need to be able to treat the disease independent of the site of origin.

In a Penn State study funded by Chinese Medicine Holding LTD. and released in September 2012, dogs with hemangiosarcoma were treated with a compound derived from the Coriolus versicolor mushroom, resulting in the longest survival times ever reported for dogs with the disease.

The Coriolus versicolor mushroom, known commonly as the Yunzhi mushroom, has been used in traditional Chinese medicine for over 2,000 years. A compound within the mushroom, polysaccharopeptide, or PSP, is believed to have immune-boosting properties. Over the past two decades, studies have indicated that PSP may also have a tumor-fighting effect.

Penn State researchers mounted a study of dogs with naturally occurring hemangiosarcoma to see what effects, the Yunzhi mushroom would have on their patients. Fifteen dogs that had been diagnosed with hemangiosarcoma participated in the trial. Divided into three groups of five, each group received a different dose — 25, 50 or 100 mg/kg/day — of I’m-Yunity, a formulation of PSP which is also readily available over the Internet. The dog owners were instructed to give their dog a capsule of I’m-Yunity, daily. The owners brought their dogs to Penn’s Ryan Veterinary Hospital for follow-up visits on a monthly basis for blood sample testings and ultrasounds to determine the extent that tumors had developed or spread in the dogs’ bodies.

“We were shocked,” Cimino Brown said of Penn State. “Prior to this, the longest reported median survival time of dogs with hemangiosarcoma of the spleen that underwent no further treatment was 86 days. We had dogs that lived beyond a year with nothing other than this mushroom as treatment.”

Not only had the dog’s survival times increased with the use of PSP, but unlike chemotherapy, there were no reported side effects.  Dogs receiving the highest dosage, 100 mg/day, had the longest median survival time, however the difference in survival times between dosages was not statistically significant.

While not inexpensive, this treatment is certainly more affordable than chemotherapy.  Those on tight budgets, may consider using this supplement at the lower dosage without fear of significantly impacting survival rates.  However, it should be noted that while the PSP, I’m Yunity, extends life and improves quality of life, it has not been shown to be a cure for hemangiosarcoma.

The Penn State researchers are preparing to pursue further trials of I’m-Yunity in dogs with hemangiosarcoma to confirm and refine their results. One upcoming trial will compare I’m-Yunity to a placebo for those owners who choose not to pursue chemotherapy for their pet; the other will compare the compound with the current standard-of-care, chemotherapy.

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