We would all love to know how to prevent cancer, and while the staff here at Veterinary Oncology Services and Research Center are striving towards that goal each day, we are still a long way off. Cancer prevention strategies are definitely improving, though, and genetic testing can play a big role in supporting canine health.
Genes and Cancer
In both pets and people, our genetic makeup forms the body’s instruction manual for biological functions. DNA within each of many cells controls the development and physiology of your pet’s body.
Dogs have about 19,000 genes that influence what traits they have physically and biologically. Approximately 100 of these genes play a vital role in the division of cells within the body, and oftentimes when cancer develops, it is due to a mutation in one of these genes.
This important group of genes belongs to one of two main categories:
- Tumor suppressor genes: This important family of genes keeps cell division within check. Cancer occurs when unregulated cell growth happens, so if a tumor suppressor gene is not doing its job, cancer can occur.
- Proto-oncogenes: These genes serve as an on/off switch for cell growth. They spend most of their time in the off position and only turn on when growth is necessary. A change in a proto-oncogene that turns cell growth on at an inappropriate time can result in cancer.
Each cell in the body has two copies of each gene. A mutation to one, either occurring through damage or inherited from a parent, will typically not result in cancer if the other gene is “healthy.”
Carrying an abnormal copy of a gene, though, does offer less forgiveness if the other copy becomes damaged. If both copies are abnormal and neither functions appropriately, the risk of cancer is high.
Bad copies of genes can also carry more than one mutation, which can make the resulting effect (in this case cancer) magnified or more complicated.
Genetic Testing and Canine Cancer Prevention
As we learn more and more about the genes our pets carry and which ones play a role in cancer development, we can use genetic testing as an important tool in our cancer prevention strategies.
Knowing your dog’s breed and potential genetic predispositions can be invaluable. Research into canine genetic cancer predispositions is still well behind that in the human field, but we do have some good information at our disposal.
We are able to detect mutations in genes including:
- BHD: a gene linked to kidney cancer in German Shepherd Dogs
- P53: an important tumor suppressor gene that is frequent affected by mutations
- WAF-1: a tumor suppressor gene often implicated in canine melanoma and osteosarcoma
- BRCA1 and 2: genes linked to the development of canine mammary cancer
- KIT: a proto-oncogene that can play a role in malignant melanoma and gastrointestinal tumors
Understanding that these mutations are present does not help us to prevent cancer exactly, but it can make us more aware of risks, develop better breeding plans, and to catch cancer much earlier due to a heightened awareness.
Genetic testing for pets with cancer can also be valuable in the course of treatment. Knowing the genetic makeup of a tumor can help us to use more targeted therapy and increase success rates in treatment.
Genetic testing seems to be the forefront of progress in canine health preservation and cancer prevention. We are excited to see where the research leads in the coming years. Please feel free to contact us with questions about your pet and cancer. We are proud to be an ever growing resource to the community.