A new study published in Science reports that cats and humans share many of the same tumor-causing genetic mutations, a finding that could guide cancer treatments for both pets and people. Researchers assembled a feline “oncogenome”—a catalog of cancer-associated mutations—using samples from nearly 500 cats across Canada, the UK, Germany, Austria and New Zealand. They screened 13 types of feline cancer for changes in roughly 1,000 genes known to drive human cancers and found a striking overlap between species.
Major results include:
– About half of the cat tumors carried mutations in FBXW7, a gene associated with aggressive breast cancer in humans.
– Just under half of the samples had mutations in PIK3CA, another gene implicated in human breast cancers.
– TP53 (p53), a key cancer driver in people, was the most frequent mutation observed across the cat tumors.
Because pet cats develop spontaneous tumors while living in the same environments as their owners—exposed to sunlight, household chemicals and urban pollution—they can be a more relevant model for some cancers than laboratory rodents. Louise van der Weyden of the Wellcome Sanger Institute, senior author of the paper, emphasized that studying mostly non-pedigree housecats gave the team a genetically diverse population, improving their ability to identify mutations common to cats and humans.
The oncogenome may also help reveal environmental hazards in homes. If a cat in a household develops a genetic change linked with, for example, mammary cancer, that finding could signal similar risks for people living there. The researchers also detected UV-related mutation patterns in cats that mirror those seen in human cancers, supporting the idea of pets as sentinels for shared environmental threats.
The work already has clinical implications. A 2025 study at the University of California tested a drug used for human squamous cell carcinoma in cats with oral squamous cell cancer; treated animals lived on average about six months longer than untreated cases. UC researchers said the oncogenome’s confirmation of shared, high-prevalence alterations—such as mutations in p53—supports efforts to develop personalized therapies that could benefit both species.
Van der Weyden and colleagues plan to expand the dataset by including more cats from additional countries to broaden understanding of shared cancer causes. Much of the material for the study came from diagnostic biopsy samples provided by pet owners, which reduces the need for invasive experimental procedures and enables research that can help pets while offering insights relevant to human cancer biology.
Edited by Zulfikar Abbany