Cancer is the leading cause of death in adult dogs. Approximately 6 million dogs will be newly diagnosed with cancer each year in the United States, with senior dogs at particular risk. It’s a diagnosis nobody wants for their beloved pet, but thankfully there are powerful new tools to detect cancer in dogs earlier and new treatments on the horizon that may improve upon current approaches to managing the disease.
Just as research is leading to advancements for humans fighting cancer, scientists are looking for new ways to help dogs, too. The following innovations in canine cancer diagnosis, treatment, and prevention provide hope for our furry companions.
Liquid Biopsy for Early Detection of Cancer
Cancer is often treatable, but your dog will have the best chance of a positive outcome if treatment starts early. That means detecting and diagnosing the disease as soon as possible. Because your dog can’t tell you when they feel off, you might not notice any early clinical signs, like a lump or decreased appetite, right away. That also makes it challenging for your veterinarian to catch cancer early.
But there is a new cancer screening test now available for dogs that can be used as part of a routine wellness visit before your dog shows any clinical signs of disease.
Known as a “liquid biopsy,” and very similar to testing now available for early cancer detection in humans, this test requires nothing more than a blood draw from your dog. The blood sample is sent to a lab where it’s processed to isolate cell-free DNA—which is the genetic material that’s no longer within a cell. The lab examines the cell-free DNA for mutations that indicate it came from a cancerous cell rather than a healthy one.
False positives are quite rare, but a positive result by itself isn’t enough to make a specific diagnosis. Your vet will run further tests to identify the type and location of the cancer. They might use imaging, such as x-rays and ultrasound, or they might obtain a sample of the suspected cancerous tissue. Treatment can typically start immediately, giving your dog the best chance of fighting the disease before it advances to a later stage or spreads throughout the body.
As with cancer in people, a simple surgery is often all that’s needed to remove the cancer in a dog, if caught early enough. Radiation therapy, and traditional chemotherapy, are also commonly used in the management of cancer in dogs, with greater benefits the earlier the intervention is started. Pain control, for improved quality of life, can also be started sooner with earlier detection of the disease.
Screening for early cancer detection is especially important for dogs over the age of seven (and potentially younger in certain breeds that tend to develop cancer earlier in life). This test can be a regular part of annual health monitoring, just as a person might get a colonoscopy or a mammogram. Also, liquid biopsy is non-invasive and provides a safe option for screening your dog for cancer. Talk to your veterinarian about whether this test is right for your dog and when you should add it to routine wellness testing.
Other innovations are currently being researched to further help improve the treatment of canine cancer.
Targeted Drug Therapy for Canine Cancer
The mainstay of medical therapy for canine cancer is chemotherapy, and it is currently used to help dogs achieve longer periods of good quality of life for many types of cancer. Chemotherapy involves the use of drugs that kill fast-growing cells in the body. Although cancer cells grow faster than most healthy cells, many of these drugs aren’t targeted specifically at those dangerous cells—healthy cells that multiply quickly can be affected as well. But thanks to new approaches used for treating human cancers, targeted drug therapies may allow more precise treatment for canine cancer.
With targeted therapy, also known as precision or personalized medicine, a veterinarian may be able to tailor the drug treatment to the unique genetic mutations in a dog’s cancer cells, after a sample of the cancerous tissue is tested in a lab; such testing will look at the DNA in the sample to identify targetable mutations and determine what drugs might be effective, providing more treatment options for dogs with cancer.
Another advancement borrowed from human cancer treatment is immunotherapy. It comes in various forms, from vaccines to checkpoint inhibitors (these block proteins that prevent the immune system from attacking cancerous cells), but the purpose is to boost the body’s own immune system so it can fight the cancer more effectively.
Although cancer cells can be identified by the immune system as foreign invaders, they frequently escape detection. They might suppress the immune system or use checkpoint proteins to fool it. And if the immune system can’t “see” the cancer, the body can’t fight against it.
Immunotherapy can teach a dog’s immune system how to recognize specific cancer cells, then attack them. A dog’s own immune cells, such as T cells, which are a type of white blood cell, can be boosted; or certain agents can be administered to help the dog’s immune system respond better.
For example, laboratories may be able to develop personalized vaccines using your dog’s cancerous tissue sample. Then, when your veterinarian injects the therapeutic vaccine into your dog, the vaccine may kick your dog’s immune system into gear, teaching it to target that precise cancer.
Another goal of immunotherapy is the prevention of the disease from returning—or from happening at all. And that’s what researchers hope for as they study preventative canine cancer vaccines. Three institutions, including the University of Wisconsin School of Veterinary Medicine, are participating in the Vaccination Against Canine Cancer Study, which is the largest clinical trial of its kind. The goal is to test a new vaccine strategy that would prevent dogs from developing cancer in the first place.
Vaccines work by priming the immune system to attack specific invaders. Once the immune system has a memory of those invaders, it can recognize and attack them in the future. The cancer vaccine under study targets several common canine cancers like lymphoma and osteosarcoma. It contains around 30 abnormal proteins that are found on the surface of cancer cells. These abnormal proteins are usually only found in dogs with cancer, so by exposing a healthy dog’s immune system to them, it’s hoped they can turn on the body’s natural defenses if cancer ever occurs.
Although it’s unknown whether the preventative vaccine approach will prove effective, researchers are hopeful. They will be monitoring the health of the study participants for the next five years to see if cancer rates are reduced. If the vaccine does prove beneficial, it could lead to similar vaccines for humans. It’s yet another way our best friends are enhancing our lives.
PetDx® – The Liquid Biopsy Company for Pets™ is a San Diego-based molecular diagnostics company dedicated to unleashing the power of genomics to improve pet health. The company’s flagship product, OncoK9®, enables veterinarians to detect cancer in dogs with a simple blood draw. As a first-in-class multi-cancer early detection (MCED) test, OncoK9 employs cutting-edge genomic analysis that leverages next-generation sequencing (NGS) technology and proprietary bioinformatics algorithms, empowering veterinarians to provide superior care to canine patients. To learn more, visit petdx.com and connect with us on Facebook, Instagram, LinkedIn, and Twitter.