By Dr. Chris Pinard
If your pet has recently been diagnosed with a canine cancer, you have probably been doing your own research about the array of treatment options available. Through your research, you may have come across cancer vaccines for dogs either in the literature or online. The goal of this article is to help you better understand cancer vaccines and give you, the pet owner, some basic information prior to your appointment with your oncologist.
What Are Cancer Vaccines?
Cancer vaccines come in many forms, many of which are still at their preliminary stage of development. There have been vaccines developed for melanoma and osteosarcoma (bone cancer) as well as specific antibodies (protein complexes that recognize and help the immune system target specific markers) targeted against canine lymphoma. The field of immunotherapy in treating cancers has been thoroughly investigated and continues to be an exciting field in human medicine. It is also gaining tremendous popularity in treating canine cancers.
If you think about it, the basic mechanism of stimulating and allowing your own body to recognize a cancer cell as a foreign intruder makes inherent sense. The problem is, mechanisms that work in a cell culture environment/lab setting may not necessarily work in a clinical setting or in an actual patient with cancer.
Cancer cells are very smart and have many mechanisms by which they evade the immune system. These mechanisms help them prevent themselves from being recognized as “foreign” and being destroyed. Therefore, the goal of the cancer vaccine is to override those mechanisms and give the immune system a specific target. This may or may not be combined with standard chemotherapies to provide the best long-term control and quality of life.
What Vaccines for Dogs Are Out There?
Vaccines and antibodies specific to certain types of cancers in pets have been developed. There are more widely available vaccines for people; however, there is increasing demand and research in the veterinary field. This translational approach to studying cancer vaccines—and how the immune system plays a role in cancer—has been imperative for many of the advancements we are starting to see in cancer care as a whole. Both melanoma and, most recently, osteosarcoma have specific vaccines developed for those types of cancer. You should discuss the melanoma vaccine with your oncologist to see whether it has a role in cancer control for your pet.
An osteosarcoma dog vaccine is currently still being studied, but commercial production is likely to be pursued shortly. A clinical trial is available for eligible pet patients with osteosarcoma at multiple institutions across the United States as well as a veterinary school in Canada.
Is There Any Data?
There have been journal articles published for both the melanoma vaccine and the recently developed osteosarcoma vaccine. The osteosarcoma dog vaccine uses an inactivated (i.e., not pathogenic) version of a Listeria bacterium. The bacteria within the vaccine has had a protein that is found on some canine osteosarcomas artificially inserted. By stimulating the immune system to the protein presented by this bacterium, cancer cells may be destroyed.
In a study conducted by the University of Pennsylvania, 18 dogs who received the vaccine showed promising results. The vaccine was overall quite safe, and dogs lived significantly longer than historical controls. A larger study is currently underway through the comparative oncology trials consortium (COTC) and may be available at an institution near you. First, you would need to have a discussion with your local veterinarian or oncologist.
The melanoma vaccine has showed some promise, and initial studies were very promising; clinically, your oncologist should ensure that your pet is the right candidate for the vaccine.
How Do I Get My Pet Treated?
Any treatment discussions should be done with your veterinary oncologist. Depending on the practice or institution, canine cancer vaccine availability may be limited, and there are still standard of care options for which rigorous data has been presented. These will also be discussed with you by your oncologist.
The outlook for cancer vaccines and cancer immunotherapy is exciting and appears to hold promising results. We as clinicians—and many of you as pet owners—continue to be optimistic and hope that the available clinical trials will help advance and accelerate cancer care for both pets and humans.