U of G Research Paves the Way for More Accurate Cancer Prognosis in Dogs with Osteosarcoma

Receiving a cancer diagnosis for your four-legged companion is hard enough. Yet, determining what to do next can be equally stressful for both the pet owner and the veterinarian.

While cancer treatment protocols can be aggressive, the results are hard to predict. For example, the treatment protocol for canine osteosarcoma – an invasive bone cancer found typically in older, large-breed dogs – often involves a high rate of tumour spread. Treatments can include amputation and extensive chemotherapy. While for some dogs these treatments can extend their life expectancy by over two years, others may only live for a couple of weeks post-treatment.

A challenge for veterinarians treating these cancer cases lies in the accuracy of traditional prognostic tools. Current methods often involve looking at a slice of the tumour under a microscope and assigning it a grade based on its appearance. However, this method is poor at predicting how osteosarcoma patients respond to treatment. But what if there was another way?

Enter microRNAs, a relatively recent discovery by U.S. scientists Drs. Victor Ambros and Gary Ruvkun that earned them the 2024 Nobel Prize in Medicine. MicroRNAs are quickly gaining popularity as a new diagnostic tool, particularly in cancer research.

What are MicroRNAs?

MicroRNAs are small molecules present in all tissues and bodily fluids, including blood. They play a role in regulating gene expression, by controlling how cells function, grow, and behave. In many diseases, including cancer, microRNAs are dysregulated, and their normal levels become altered. The discovery has opened new possibilities in human and veterinary medicine, aiding in the understanding how diseases like cancer develop and how they may or may not respond to treatment.

Dr. Geoffrey Wood, a professor at the Ontario Veterinary College at the University of Guelph, recently published a study in PLOS ONE scientific journal, examining 56 microRNAs found in plasma samples from dogs with osteosarcoma. Of these, a specific microRNA dubbed miR-214-3p emerged as a particularly significant marker. This microRNA was not only elevated in all dogs with osteosarcoma compared to healthy dogs, but its high expression levels were also associated with shorter survival times and a faster disease progression.

“MicroRNAs are very stable in blood samples and are also relatively easy to measure. This makes them practical tools for cancer prognosis, and potentially also for early detection of cancer.” Further, Wood’s research established a multi-microRNA model. While miR-214-3p is a strong predictor on its own, using multiple miRNAs together provided an even more accurate prediction of a patient’s prognosis and responsiveness to treatment. “We are actively working to turn this discovery into a quick and practical test that can help owners and veterinarians make important treatment decisions,” says Wood.

A Glimpse into the Future of Cancer Treatment

For veterinarians and pet owners, the ability to accurately predict the prognosis of a dog with osteosarcoma can enhance treatment planning. Knowing whether a dog is likely to have a shorter or longer survival time can help guide decisions regarding aggressive treatments like chemotherapy and amputation or focus on palliative care to ensure the patient’s quality of life.

As microRNA testing becomes more widely available, pet owners could receive more personalized information about their dog’s prognosis, allowing them to make the best possible decisions for their beloved companions. Wood’s lab is expanding this research to other cancer types including hemangiosarcoma and lymphoma. Along with University of Guelph collaborators, his lab is expanding this work to measure microRNAs in human osteosarcoma patients, with funding from the Ontario Institute for Cancer Research.

The study of microRNAs in canine osteosarcoma is still in its early stages, but it holds tremendous potential. Beyond just offering a tool for diagnosis and prognosis, microRNAs could become a cornerstone of future treatments as new therapies are emerging that can inhibit microRNAs to counter their effects.

Wood’s research study was also funded by OVC Pet Trust.