New research in Science finds cats and humans share many tumor-causing genetic mutations, a discovery that could inform cancer treatments for both pets and people.
Researchers built a cat “oncogenome” — a catalogue of cancer-associated gene mutations — using samples from nearly 500 cats across Canada, the UK, Germany, Austria and New Zealand. They analyzed 13 feline cancer types for mutations in 1,000 genes known to drive human cancers and found striking overlap.
Key findings:
– About half of the cat cancer samples carried mutations in FBXW7, a gene linked to aggressive human breast cancer.
– Just under half had PIK3CA mutations, another gene implicated in human breast cancers.
– TP53 (p53), a major driver in many human cancers, was the most common mutation in the cat samples.
Because cats develop spontaneous tumors in real-world environments — sharing pollution, sunlight and household exposures with their owners — they may provide a more relevant model for some cancers than laboratory rodents. Louise van der Weyden of the Wellcome Sanger Institute, senior author of the study, highlighted that using mostly non-pedigree housecats gave the researchers a genetically diverse pool to identify mutations shared by cats and humans.
The oncogenome could also help identify environmental risks inside homes. If a genetic change associated with, for example, mammary cancer appears in a family cat, it might point to similar risks for humans in the same household. The team observed UV-related mutations in cats that matched patterns seen in people, supporting the idea of pets as sentinels — “the canary in the coal mine” — for environmental hazards.
Clinical relevance is already emerging. A 2025 US study from the University of California tested a drug used for human squamous cell carcinoma on cats with the oral form of the disease; treated cats lived, on average, around six months longer. The UC researchers welcomed the oncogenome data, noting high-prevalence alterations — such as in p53 — in both species support developing personalized therapies that could benefit animals and humans.
Van der Weyden and colleagues hope to expand the dataset by including more cats from additional countries to broaden understanding of shared cancer causes. They note that much of the research relies on biopsy samples contributed by pet owners, minimizing harm to animals compared with laboratory experiments. Many owners consent to use of diagnostic samples for research, enabling studies that could yield treatments for pets and insights relevant to human cancer.
Edited by Zulfikar Abbany