The bone cancer known as osteosarcoma is rare in children, with only up to 1,000 cases a year. However, it’s a common cancer in dogs, with over 25,000 cases a year. For both people and dogs, the disease is the most commonly diagnosed primary bone tumor. It is an aggressive form of cancer that tends to spread to the lungs.
Osteosarcoma (OS) has a relatively low survival rate in both species, and there have been scant advances in treatment over the past thirty years. Any breakthrough in fighting this deadly disease is valuable, and recent research on dogs may ultimately lead to just that.
Bone Cancer in Dogs and Humans
A new scientific study has shown that there is a genetic similarity between human OS and the same cancer in dogs. The research, published in Communications Biology, was carried out by Tufts University and the Translational Genomics Research Institute.
The scientists looked at 59 dogs with OS tumors. Dogs studied included several different breeds such as Greyhounds and Golden Retrievers, as well as mixed breeds. Genetic material in a sample of each dog’s tumor was sequenced, as was a matched sample of normal tissue. Researchers collected and sequenced samples from any additional metastasized tumors as well.
The scientists discovered that the genomic features of the dogs’ OS shared many qualities with human OS. For example, the genetic complexity is similar in both, and both show low mutation rates.
Although dogs largely develop OS as adults and OS is a disease of human children, it was also determined that age does not distinguish canine and human OS. This is due to the similar genomic features and clinical expression of the illness in both species. The study concluded that dogs are a useful large animal model for studying new treatments and therapies for human OS.
Comparative Oncology Holds Promise
Does using dogs as a model for human OS mean hope for future treatments? The short answer is yes. The field of comparative oncology is incredibly promising. Comparative oncology is the use of naturally occurring cancers in animals as a model for similar cancers in humans. Just like OS, many animal cancers, such as soft tissue sarcoma and melanoma, are similar in both species. For these specific cancers, dogs are ideal study subjects.
Cancers can happen spontaneously in dogs, and dog owners are often likely to seek out specialized treatment. They might go to a veterinary oncologist or teaching hospital to find the best possible care. Services provided there are similar to what may be provided to a human patient. Surgery, radiation therapy, and chemotherapy are among the shared cancer treatment options.
About 6 million dogs in the United States are diagnosed with cancer each year. Although not all cancers will be similar to human cancer, that’s still a huge subject pool for research. Dogs have become a significant resource for studying these shared cancers and treatment outcomes. In addition, they may help in determining the efficacy of potential new treatments.
The Value of Dogs As Human Cancer Models
Dogs aren’t closely related to people. So can they really be valuable models of human disease? Well, more than 30 years ago, dogs were first used to optimize bone marrow transplant protocols. And the benefits have been growing ever since. The following factors contribute to dogs’ merit as research subjects:
- Some dog cancers share tumor biology and behavior with human cancers.
- Most dog cancers occur at a high enough rate to provide ample subjects for studies and clinical trials.
- Dogs share many environmental risk factors with humans.
- Some dog cancer tumors have identical microscopic structure and respond to conventional chemotherapy with the same rates.
- Dog lifespans, the rapid progression of dog cancers, and the early spreading of diseases allow clinical trials to be completed in a short time.
Thanks to these factors, comparative oncologists have been studying dogs for human benefit for years. Dogs help to understand environmental risk factors for cancer and evaluate new cancer treatment strategies.
Dogs have benefited too, as comparative oncologists have also studied genetic and familial factors for the cancer predispositions seen in certain breeds. The key point with all comparative oncology studies is not just that cancers in dogs will contribute to a greater understanding of cancer in general, but that both dogs and humans will benefit. And with this latest study on OS, even more benefits may be just around the corner.
November is National Pet Cancer Awareness Month. Cancer is the leading disease-related cause of death for domestic dogs and cats in the United States. This month, we’re spreading the word to help educate pet owners about how to best protect their furry family members.