Dogs and people develop cancer at about the same rate, with a lifetime risk being from about 1 in 2 to 1 in 3. Daunting odds – but this is due in part to increased longevity. Due to social, industrial, and medical advances, we and our dogs are simply living longer. Dogs in the wild have a life expectancy of 4-6 years, but domestic pet dogs have a life expectancy about twice that long. Because cancer is a disease that arises from mutations, more days alive means more cell divisions to maintain our bodies – and more chances to accumulate mutations.

Certain environmental factors, like tobacco products, can speed up mutations that may lead to cancer. However, the main cause of mutations, known as mutagen, is the natural rate of errors that occur during the regular process of replicating DNA. There is no escaping the risk of cancer due to aging. Nevertheless, some factors that contribute to this risk might be altered. Cancer prevention research is an area of vigorous investigation that strives to figure out which factors can be modified to reduce risk and how they might be modified. One consistent finding is that lean body mass has a protective effect against cancer; this seems to be true in mice, monkeys, dogs – and people. In female dogs, spaying before the first heat is protective against mammary cancer; the incidence of mammary cancer in dogs spayed before their first heat is virtually zero, compared to about 10% (1 in 10) for intact females or females spayed after several heat cycles. Limiting opportunities for dogs to roam will not only protect against injury and death from fighting or being hit by cars but also will reduce exposure to transmissible venereal tumor (TVT) in areas where it is endemic (as in the southern border states).

Feeding a balanced diet, whether commercial or custom (as long as it contains all the necessary nutrients for growth, maintenance, and good health), in amounts that support a lean body mass is the only nutritional advice we can stand behind. We do not recommend adding any supplements to a balanced dog food diet except under the advice of a veterinarian (ideally, a veterinary nutritionist). Supplements are widely used by people in Europe, and while most do not cause harm (but also provide little or no benefit), there are plenty of medical reports that document some as toxic or as having otherwise bad health consequences. There are many products marketed in pet stores, in health food stores, and on the Internet that have not been rigorously tested for safety and/or efficacy. We caution people to be informed about any supplement or “alternative remedy” they give their pet, checking whether all the supplement’s ingredients are known and listed and whether it may interact with medications or other food the pet may routinely receive.

Clinical trials are experiments, carried out in a clinical setting, that are meant to benefit the next generation of patients, not necessarily the participants. They test new ideas that were developed in the research lab. While all trials start with the intent of moving into the clinic treatments that will improve on the standard of care, their outcomes are unknown; some new treatments may be better than the best care available at present, but many will be only equally or even less effective. So, participation in a clinical trial carries unknown risks and uncertain outcomes. (Please see the University of Minnesota’s Clinical Investigation Center (CIC)opens a new window  , for information regarding ongoing clinical trials.)

Please see the Clinical Trials page for links to our current studies, including any that are actively looking for additional samples.

Taken as a tumor in general (including its counterpart seen in humans and in mice – angiosarcoma), HSA is a far more common cancer in dogs than in any other species, even though it is not the most common cancer found in dogs. It is estimated that HSA accounts for 5-10% of all tumors in dogs (angiosarcoma accounts for only about 0.01% of all tumors in humans). By comparison, lymphoma accounts for about 20% of all tumors in dogs, and mast cell cancer may account for an even higher percentage.

No – or, at least, not exactly. The NCI (National Cancer Institute) definition of a familial (inherited) cancer is a cancer that occurs in families more often than would be expected by chance. Familial cancers often strike victims at an early age and may indicate the presence of a gene mutation that increases cancer risk. They may also be an indication of environmental or lifestyle factors shared by family members. Some breeds are at greater risk for developing HSA, and this risk is most probably due to heritable traits. But HSA is not heritable in the sense that affected parents would always pass it on to offspring. Some risk factors will probably be responsive to selecting which dogs to breed, but some risk factors may be firmly embedded in the breed (fixed traits).

When we talk about “risk”, each dog is independent from any other dog. If two golden retriever littermates (or four littermates, or eight littermates) develop HSA, it does not necessarily imply that this was a “high risk” breeding. If the cancers occur when the dogs are older adults, then those dogs need to be considered in the context of the whole population (or at least of their whole generation); more than likely these dogs fall in the population that were statistically likely to develop HSA (nearly 20% of Golden Retrievers). Likewise, in a litter of, say, seven Portuguese water dogs, if one were to develop HSA, the rest would not be “protected” by the expected 1 in 15 occurrence in a PWD litter. Risk does not work this way.

Imagine risk this way: Two people begin flipping coins at the same time. Both will get heads and tails about 50% of the time, but what Person A gets in a toss does not influence what Person B gets on the same or subsequent tosses – just like the result of one toss by any individual does not influence or predict the result of the next toss. Every toss is a 50/50 chance of heads or tails. The same is true of cancer risk and dogs.

A litter with multiple animals that developed a rare cancer at a very young age would trigger a high level of suspicion that there may be a heritable component related to the breeding or to one of the parents. However, this is not the case with HSA; in Portuguese water dogs, for example, the median age at diagnosis is about 10 years, just as we see in most other breeds.

The bottom line is: we don’t know. We are actively asking this question in our research and through clinical trials.

The sites where hemangiosarcoma tumors most commonly arise are spleen, heart, and skin, but they may occur virtually anywhere blood vessels form. The standard of care is surgical removal of the primary tumor if there is no visible metastatic disease (determined through routine chest radiographs and abdominal radiographs or ultrasound), with adjuvant chemotherapy using doxorubicin. A couple of alternative protocols exist – for example, vincristine/doxorubicin/cytoxan – which seem to have about equal efficacy. Metronomic chemotherapy (lower doses administered more frequently) may be as effective as conventional chemo, but it does not appear to be better.

The principal reasons for surgery are to eliminate the major mass and source of tumor cells (especially when gross metastasis is not evident) and to reduce the chance of a lethal bleeding episode. The addition of chemotherapy is to delay recurrence from microscopic spread, which exists in virtually every dog diagnosed with HSA. Surgery alone has benefit (simply by reducing the probability of a lethal bleeding episode), and for some dogs it is curative (probably for those whose tumor has uncharacteristically remained confined to one site, as is often the case with skin tumors). Chemotherapy can be used alone in certain circumstances, when temporary palliation is desirable and surgery cannot be done (as for tumors in the heart that are considered inoperable.)

Choosing a therapy depends on several individual factors and preferences: how well the patient tolerates the medications (side effects), how often the patient can present for treatment, etc. An open dialogue with your veterinarian and oncology team is the best strategy for pursuing treatment for your dog’s particular case.

The median survival for dogs given standard of care for a primary tumor and no detectable metastases is about 180 days. Age does not seem to influence outcome. About 10-15% of dogs with HSA do remarkably well with treatment and have extended remissions. Some of these dogs go on to live full lives without recurrence; it seems that as they reach 12-14 months without recurrence, each day decreases the chance they will relapse. However, about 35% of dogs surviving longer than 4-6 months will fail to reach one year. And about 50% of dogs will die within 4-6 months of diagnosis. This is a very bad disease.

In all likelihood, none. Aside from visible skin tumors from the skin variety (which also tends to have the best outcome with treatment), HSA is a silent, insidious disease. “Warning signs” don’t appear until the situation is dire or even too late. The tumor itself does not cause pain or discomfort; the organs where the tumor usually grows are not highly innervated, and the tumor tends to invade areas where there is a lot of elastic tissue where its edging out of normal tissue does not cause apparent distress.

At present, there are no “early detection” tests that will predict an eventual diagnosis, and there are no simple laboratory tests that are highly specific and sensitive to diagnose HSA. Imaging plus biopsy is the only way to obtain a definitive diagnosis. Because there are other conditions that can resemble HSA on imaging, we strongly suggest that any dog have a biopsy (which could be collected during surgical removal of the tumor or affected organ) when there is a suspicion of HSA, and that the biopsy be processed and interpreted by an experienced pathologist.

There are several ancillary tests that could be used to guide if the need for surgery is immediate, but we do not recommend using these tests to make definitive patient management decisions. We do encourage owners to ask, “Why are we doing the test?” and “How do positive or negative results from this test help us?” and to inquire about testing options, just as they would inquire about treatment options.

There is no evidence to support a link between plastic, vinyl, or rubber products and cancer in dogs or in people. Because occupational exposure to vinyl chloride was recognized as an increased risk for HSA of the liver in people who cleaned reactors used in the manufacture of PVC, many people (and a few websites) mistakenly conclude that rubber and plastic products cause HSA. Finished PVC products are not the same as monomeric vinyl chloride, and despite newer concerns about softening agents in PVC products, no evidence supports them as being a cancer risk.

Not at this time.

According to the definition provided by the National Cancer Institute, a biopsy (by-op-see) is the removal of cells or tissues (from a growth, organ, or lesion) for examination by a pathologist. The pathologist may study the tissue under a microscope or perform other tests on the cells or tissue.

There are several different types of biopsies that can be performed: an incisional biopsy is when only a sample of tissue is removed. An excisional biopsy is when an entire lump or suspicious area is removed. A needle biopsy, core biopsy, or fine-needle aspirate is when a sample of tissue or fluid is removed with a needle. Any of these types of samples may provide the pathologist with sufficient information to make a diagnosis of cancer. However, the rule ‘more is better’ generally applies when it is important to accurately classify and stage that cancer.

Non-invasive tests such as radiographs, ultrasound, or magnetic resonance imaging (MRI) can indicate suspected cancer, but a biopsy provides the tissues needed to make a definitive diagnosis.

A fine needle aspirate is a first-line procedure which can narrow the list of possible diagnoses. In many cases, it provides all the information needed to formulate a treatment or management plan. The FNA is the least invasive biopsy procedure. The patient is usually awake or only lightly sedated, a needle is inserted into the abnormal tissue, and cells are pulled (aspirated) into the needle and the syringe. The cells can then be placed on a glass slide for microscopic examination (cytopathology), or they can be placed in a preservative for other tests. The advantages of the procedure are that it is minimally invasive and generally very safe, it is less costly than an incisional or an excisional biopsy, and the results can be obtained rapidly. The disadvantages are that the tissue architecture is destroyed, so the information that can be learned from the sample is limited. Finally, the amount of sample is small, so additional tests require additional samples.

Incisional biopsies are more invasive than fine needle aspirates but can be obtained safely and at reasonable cost. A “tru-cut” biopsy tool, which is similar to a needle with a larger channel, is inserted into the tissue, and as it penetrates, it also cuts, allowing a small core to remain in the needle channel. This core of tissue is then removed and can be used for cell pathology, and it can be placed in a preservative for additional tests. The most common test done by a pathologist is examination of formalin-fixed and paraffin embedded tissue that has been subjected to several additional processing and staining steps under the microscope. The advantages of an incisional biopsy are that there is more tissue available for analysis, and the architecture, or the context of how cells relate to each other, is preserved. In addition, the preserved tissue allows the pathologist to perform additional tests without the need to obtain additional samples. This provides a more complete picture to accurately classify and stage the disease. Because tissue imprints can be obtained from these samples, a provisional diagnosis can also be obtained. The disadvantages are that it is more invasive (it usually requires at least a small “nick” in the skin to allow the needle to be placed into the tissue), it requires heavy sedation or general anesthesia, it takes longer to process and read, and consequently, it is more costly. In some cases, it is necessary to remove a large piece of tissue (“wedge biopsy”) in order to provide the pathologist sufficient material to reach a diagnosis.

Excisional biopsies are done when there is an opportunity to remove the whole tumor without significantly added risk to the patient. The advantages and disadvantages are like the incisional biopsy above. An example of an excisional biopsy is removal of a lymph node.

Liquid biopsies are tests that use blood or other body fluids to find out if someone has cancer, to determine the best options for treatment, or to monitor how patients respond to treatment. The earliest liquid biopsies involved looking at chromosomes under a microscope to find abnormalities, specifically to find out if patients had certain types of leukemia. In the past 20 years, advances in technology have made liquid biopsies more useful. Now they can detect cancer early, classify diseases, check for small amounts of remaining disease, and even assess the risk of developing a disease by measuring different substances in the blood, like DNA and proteins.

Recently, the company Grail conducted a study involving 15,000 human patients at 142 different sites. They wanted to see how well different liquid biopsy tests could detect various types of cancer. The tests looked for 1) mutations in genes, 2) abnormalities in the number of copies of certain genes (CNA), and 3) specific patterns of chemical changes in DNA called methylation. The mutation tests had high specificity (a positive result is typically associated with the presence of cancer), but they often gave false negatives (low sensitivity). They also weren’t ideal for pinpointing where the cancer might be. The CNA tests had moderate accuracy, acceptable sensitivity, but not-so-great ability to locate the cancer. The methylation tests performed the best and were chosen for further development. They led to the creation of the Galleri test.

Ongoing studies in humans are being conducted to see how useful the Galleri multi-cancer early detection test is in improving patient outcomes. The recently completed Pathfinder study tested over 10,000 patients between the ages of 40 and 77, from seven different health systems. The test found signs of cancer in 1.4% of the patients, with the highest percentage in high-risk populations. They confirmed 36 different types of cancer in 35 individuals. Initial analysis showed that the test was 97% accurate in identifying the most likely type of cancer based on the affected tissue. Further analysis revealed that 0.9% of the population had cancer, and the test had a 99.1% specificity (ruling out cancer when it wasn’t present), and a 43% rate of cancer when it was present.

CellSearch® assay (by Menarini Silicon Biosystems), detects circulating tumor cells in patients with metastatic breast cancer, prostate cancer, or colorectal cancer. CellSearch, originally developed by Janssen (a division of J&J), was approved by the FDA in 2004, and while the test has not been universally adopted, various studies suggest that it has value in the management of patients with these conditions.

Other liquid biopsy tests include EpiSwitch™ (Oxford BioDynamics), Guardant Reveal™ (Guardant Health) MRD (Minimal Residual Disease) test, Cologuard® (Exact Sciences), and others. These tests have major advantages, including being non-invasive and having relatively high specificity (positive results are typically associated with the presence of cancer). However, they all have the drawbacks of modest to low sensitivity (giving frequent false negatives) and unclear directions of action. In addition, because the markets are competitive, there is a lack of transparency about the methods and details of the tests. This leaves healthcare providers to make decisions without knowledge of what is being measured.

Liquid biopsy testing is an emerging field in veterinary medicine, but the lack of regulation adds to the uncertainty of testing. IDEXX is one of the companies offering versions of liquid biopsy testing for cancer. These tests have the same limitations as tests developed for human patients. However, they offer fewer benefits because there are fewer options for precision guided treatments in veterinary medicine, and because the testing (and subsequent tests recommended by the results) are not generally covered by insurance.

Cell lines derived in the Modiano Lab are available through Kerafast opens a new window. 

Constructs and other molecular resources developed in the Modiano Lab are available through Addgeneopens a new window. 

For sequence information and GEO accession codes, please contact [email protected]opens a new window. 

For methods and protocols, please contact [email protected]opens a new window.