Comparative oncology between humans and mammalian pets — specifically dogs — is revealing the ways pet cancer research could positively impact the future of human cancer outcomes.
Through a variety of ongoing clinical trials and experimental treatments, scientists have progressed a body of research stemming from the mapping of the human and canine genome. These tactics leverage the unlikely biological similarities in humans and dogs, which continue to yield new degrees of clinical cross-pollination as we learn more about genetic diseases in both species. Such advancements have grown to include a wider variety of cancer types and treatments.
Treatment as research
Though they focus on different organisms, human and veterinary oncologists have quite a lot in common in terms of training and overall educational background, making them symbiotic partners in this crucial branch of medicine.
“Veterinary oncologists go through the same training as their counterparts in human medicine,” SAGE Veterinarian Centers Chief Medical Officer Wendi Velando Rankin said. “Four years of veterinary school after college, 1 or more years of an internship, then 3 years of a residency in Oncology. Similar to human oncologists, veterinary oncologists need to pass a series of exams to become board-certified, with many of our oncologists studying with human oncologists for board exams since the tumor biology in veterinary and human medicine are similar.”
These similarities underscore the importance of comparative cancer research benefiting both humans and animals, which today is becoming increasingly rooted in practical treatment.
Unlike traditional clinical experimentation on animals, where subjects are often deliberately given disease for the purpose of observation, many cancer trials in dogs are serving as a complement to existing specialty treatment. These studies have become more diverse in recent years, exploring different forms of cancer as they pertain to prevailing technology and research.
For instance, a 2017 study published by Veterinary Medicine and Science explored treatment for canine mammary cancer as an optimal reference point for that of humans, noting that “canines are excellent models for cancer studies due to their similar physiology and genomic sequence to humans, companion status, and limited intra-breed heterogeneity.” This study ultimately advocated for “embracing the use of dogs and their simplified genetic structure” to overcome cancer-related hurdles within the comparable but inherently more complex human genome.
More recently, a report outlined the efforts of OneHealth’s FidoCure, a form of genomic and AI-based technology aimed at treating cancer in dogs. The precision-focused treatment uses gene sequencing to designate and analyze the exact mutations contributing to a dog’s cancer — a concept that is also directly applicable to a human’s genetic composition. What’s more, the treatment strives to bridge the gap between pet owners, specialty veterinarians, and biopharma drug sponsors through a proprietary dataset through which findings are logged, analyzed, and shared to spur stronger pharmaceutical discovery and reshape how human cancer is approached.
The use of cannabidiol (CBD) on cancer is also a notable basis of comparison. Earlier this year, a study by the Canine Health Foundation found that “CBD oil caused a significant decrease in [canine] cancer cell reproduction in all cell lines studied,” which included cultures from osteosarcoma, mammary carcinoma, and lymphoma. The study also notes that CBD’s anti-cancer implications were first observed during human trials, but they were further clarified during the canine trials.
Another ongoing study, conducted by Virginia Tech’s Virginia-Maryland College of Veterinary Medicine, has observed dogs with a glioma, an aggressive brain tumor with a low survival rate, and a notoriously high resistance to treatment. Commonalities between human and canine gliomas have led the college to a variety of crucial findings, including “a remarkable degree of similarity” in the tumors’ locations and cellular processes, which could revolutionize treatment for both species in the future. John Rossmeisi, the college’s Dr. and Mrs. Dorsey Taylor Mahin Professor of Neurology and Neurosurgery, said of the research: “Our results effectively position preclinical models of spontaneous canine glioma to better understand glioma drivers, those alterations that give cells a fundamental ability to transform into cancer.”
Collectively, the above efforts are a microcosm of the future of cancer treatment; they suggest a brighter horizon for both humans and canines, but such implications remain pending as research continues to progress.
A major hurdle in this process has been a lack of awareness amongst pet owners regarding clinical trials offered through specialty veterinary care. This notion, paired with existing cost-related inhibitions for standard oncological treatment, compounds an already sparse level of healthcare accessibility for pet owners.
Since much of comparative oncology research depends on trial participation, its future will depend, in part, on broader awareness building; this starts with addressing existing patient and veterinarian perceptions of communication and clinical decision making. A 2021 study of these factors found that pet owners primarily expected veterinary matters to be handled as a partnership — and that “though many pet owner expectations in relation to communication of information have continued to prevail … additional expectations related to the increase in accessibility of information have emerged.”
“[Veterinary oncologists] have the ability to help not only veterinary patients but with participation in clinical trials, [they] can help model diseases and treatments in dogs and cats that can advance research in both veterinary and human medicine,” Rankin said.
Therefore, by consistently offering access to more options for pet cancer patients — including clinical trials — specialty veterinarians can simultaneously meet these expectations, solidify more transparent patient-provider relationships, and contribute to key studies building the framework for a future without cancer.