Genetic discovery could lead to better treatments for common tumors in dogs

Newly discovered genetic similarities and differences between the most prevalent types of canine soft tissue sarcomas, a common and life-threatening tumor, could pave the way for more accurate diagnosis and better treatments in the future.

Using next-generation sequencing techniques and computational approaches, a team of Washington State University researchers and veterinarians examined the genetic makeup of the three most common tumor subtypes and identified several therapeutic targets that could form the basis of new treatments. They detailed their findings in a study published in the newspaper plus one.

“The different subtypes of soft tissue sarcomas can appear so similar that even trained pathologists have trouble telling them apart. However, it turns out that they are not all the same: they are a very diverse group of cancers,” said Eric Shelden, an associate professor in the WSU School of Molecular Biosciences and corresponding author of the study.

Up to 95,000 dogs in the United States are diagnosed with this cancer each year, and 20-30% die from the disease. There are several subtypes of sarcomas, however, because they have similar characteristics and are difficult to diagnose, they are treated in a similar way and often without success.

Rance Sellon, a WSU veterinary oncologist and study co-author, said the study findings suggest that a “one-size-fits-all” approach to treatment may no longer be appropriate for patients, and doctors may need to work more closely. . with veterinary pathologists to identify tumor subtypes for more accurate diagnosis and to investigate and identify more effective treatment options.

“From a clinical standpoint, the findings of this study suggest that perhaps our view of this type of tumor should change, and we should look to make better distinctions between the various subtypes, ultimately with the goal of better defining treatment.” and the prognosis,” he said. she said.

Previous studies have examined the possible causes of soft tissue sarcomas and have looked at genetic markers to identify subtypes of soft tissue sarcomas. However, the WSU study was the first to examine gene expression patterns in canine soft tissue sarcomas by analyzing RNA sequences from tumor samples to differentiate between tumors, understand the biology driving their behavior, and identify candidates. for drug therapies.

“We look at thousands of genes and their expression patterns at once, and then we try to tease out computationally whether there are differences between different types of tumors, and there are,” Shelden said. “Although it will probably be a few years before the effect of this study is really felt in a clinical setting, the hope is that this will make people realize that they should not treat these tumors in a similar way because they are, in fact, biologically different.”

Shelden said follow-up studies are needed to validate the findings and identify more suitable drugs to treat the different tumors.

Sellon estimated that the WSU Veterinary Teaching Hospital sees one to two dogs a week with soft tissue sarcomas. She noted that the tumors can be difficult to treat and the prognosis varies based on a number of variables, such as the size and grade of the tumor. Treatment usually involves surgical removal of the tumor followed by radiation therapy.

“A surgical cure may be difficult or impossible, depending on the size and location of the tumor, as these tumors are notorious for their locally invasive behavior that can make it difficult to acquire ‘clean’ surgical margins, margins with an adequate amount of normal tissue. surrounding the edges of the tumor,” Sellon said. “Radiation therapy can be effective in treating residual disease, but for some dogs, recurrence can still be seen after surgery and radiation therapy.”