A main cause of death in dogs is cancer, which affects about 1 in 4 dogs at certain life stages. Despite recent advancements in veterinary oncology, treatment based on a patient’s genetics, also known as precision medicine, is still not widely implemented in veterinary care. To address this gap, a group of scientists examined canine cancer mutations and their outcomes using real-world data.
The scientists examined 2,119 canines from over 200 veterinary clinics with confirmed cancer diagnoses. The canines were diverse in terms of their breeds and types of cancer. The team analyzed genetic data from the dogs’ tumor samples as well as clinical data, including their cancer type, age, weight, sex, and treatment type. Their goal was to understand how genetic alterations in cancer affect the dogs’ responses to treatment and rates of survival.
The scientists sequenced DNA segments from the dogs’ tumor samples, specifically targeting 48 genes that are connected to cancer, using a technique called targeted DNA sequencing. They used computational tools to analyze the sequencing output, called DNA sequence reads, and to compare the tumor DNA with normal DNA. This comparison allowed the scientists to detect mutations and predict which mutations were most likely to impact protein function using a computational tool called PROVEAN. They focused on the changes that could affect how the dogs responded to treatment or how their cancer progressed.
The research group examined each dog’s tumor DNA and compared it to the treatments they received in order to identify trends in genetic mutations and observe how various medicines performed in actual clinical settings. The scientists’ most unexpected discovery was that the dogs with cancer frequently had mutations in the same genes that are known to cause cancer in humans. Like humans with cancer, they had mutations in the TP53, PIK3CA, and KRAS genes, suggesting that the biology of canine and human tumors is closely connected.
Additionally, the scientists discovered that each canine cancer had a unique genetic signature. For instance, the genes implicated in canine bone cancers, such as osteosarcoma or lymphomas, were different from the ones present in canine mammary gland cancers. They stated that these differences may help veterinarians make more accurate cancer diagnoses and select treatments that have a greater probability of being effective in each unique situation.
The scientists highlighted that their study stands out because it used data from real dogs treated in ordinary vet clinics rather than controlled laboratory situations. That is, the data represent what happens in the real world, providing a more accurate picture of how treatments work in ordinary clinical settings with differences in patient diversity and access to care.
The scientists also reported that many of the dogs that received drugs based on their tumors’ DNA responded well. They interpreted this observation to mean that precision medicine is possible in veterinary clinics, and with the right genetic information, vets can avoid one-size-fits-all treatments.
The team concluded that precise cancer therapy could provide veterinarians with a useful new tool for directing treatment and enhancing the quality of life for canine patients. The scientists proposed that genetic screening could soon become a standard part of pet cancer treatment, as it becomes more widely available and less expensive. This implies fewer adverse effects, better chances of survival, and possibly more time spent with canine friends.
