Researchers examined tumors from nearly 500 pet cats across five countries. The work involved scientists from the Wellcome Sanger Institute, the Ontario Veterinary College in Canada, the University of Bern, and other collaborators. By studying these samples, the team identified key genetic alterations that drive cancer in cats and found that many of these changes closely resemble those seen in human cancers.

Environmental Risks and Genetic Overlap

Cats often share the same living environments as their owners, which means they can be exposed to similar cancer risk factors. Using DNA sequencing on tissue samples originally collected for veterinary diagnostics, the study, published in Science, showed that several genetic patterns in feline cancers mirror those found in people. One notable example is the similarity between feline mammary cancer and human breast cancer.

The findings suggest that multiple genetic pathways involved in cancer could be explored further through genomics and clinical studies. This could eventually lead to treatments that target the same mutations in both cats and humans.

First Comprehensive Map of Cat Cancer Genomics

Cats are extremely common pets, with more than 10 million living in the UK and nearly a quarter of households owning at least one1. Cancer is also one of the leading causes of illness and death in cats2, yet its genetic basis has remained poorly understood.

This study marks the first time cat tumors have been analyzed at this scale, creating an open resource that researchers can use to advance feline cancer genomics.

The team screened around 1,000 genes known to be linked to human cancer. They compared tumor and healthy tissue samples across 13 different types of feline cancer, allowing direct comparisons with cancers in humans and dogs. In several cases, the genetic drivers of cancer in cats closely matched those found in people.

Key Cancer Genes Found in Cats

Mammary carcinoma, an aggressive and common cancer in cats, provided some of the clearest insights. Researchers identified seven driver genes associated with tumor development. The most frequent was FBXW7, which was altered in more than 50 per cent of the tumors studied. In humans, mutations in FBXW7 in breast cancer are linked to poorer outcomes, reflecting a similar pattern seen in cats.

The study also found that certain chemotherapy drugs were more effective in tumor samples with FBXW7 mutations. Although these results come from laboratory-grown tissue and require further testing, they point to a possible treatment strategy for both feline mammary cancer and human breast cancer3.

Another major gene, PIK3CA, was present in 47 per cent of feline mammary tumors. This same mutation is well known in human breast cancer and is already targeted with specific drugs called PI3K inhibitors.

Shared Mutations Across Multiple Cancer Types

Beyond mammary cancer, the researchers identified similarities to human cancer mutations in tumors affecting the blood, bone, lungs, skin, gastrointestinal system, and central nervous system. These shared genetic features highlight opportunities to study cancer across species and potentially develop therapies that benefit both.

One promising concept emerging from this work is the 'One Medicine' approach. This strategy encourages collaboration between human and veterinary medicine, allowing discoveries in one field to inform the other. Treatments that prove effective in people could be tested in cats, and insights from veterinary trials could help guide human clinical research.

Researchers Highlight Cross-Species Benefits

Bailey Francis, co-first author at the Wellcome Sanger Institute, said: "By comparing cancer genomics across different species, we gain a greater understanding of what causes cancer. One of our major findings was that the genetic changes in cat cancer are similar to some that are seen in humans and dogs. This could help experts in the veterinary field as well as those studying cancer in humans, showing that when knowledge and data flows between different disciplines, we can all benefit."

Professor Geoffrey Wood, co-senior author at the Ontario Veterinary College, Canada, said: "Despite domestic cats being common pets, there was very little known about the genetics of cancer in these animals, until now. Our household pets share the same spaces as us, meaning that they are also exposed to the same environmental factors that we are. This can help us understand more about why cancer develops in cats and humans, how the world around us influences cancer risk, and possibly find new ways to prevent and treat it."

Professor Sven Rottenberg, co-senior author at the University of Bern, Switzerland, said: "Having access to such a large set of donated tissues allowed us to assess drug responses across tumor types in a way that hasn't been possible at this scale before. This is a powerful tool to help us identify potential novel therapeutic options that we hope will translate to the clinic one day, for both cats and humans."

Dr Louise Van Der Weyden, senior author at the Wellcome Sanger Institute, said: "This is one of the biggest ever developments in feline oncology and means the genetics of domestic cat tumors are no longer a 'black box'. We can now begin to take the next steps forward towards precision feline oncology, to catch up with the diagnostic and therapeutic options that are available for dogs with cancer, and ultimately one day, humans."

Notes

1. Cats Protection. Accessed 04/12/2025. Available at: https://www.cats.org.uk/about-cp/cats-report
2. A. L. Sarver, K. M. Makielski, T. A. DePauw, A. J. Schulte, J. F. Modiano. (2022) 'Increased risk of cancer in dogs and humans: a consequence of recent extension of lifespan beyond evolutionarily-determined limitations?' Aging Cancer. DOI: 10.1002/aac2.12046
3. For this part of the study, researchers used feline mammary carcinoma tissue grown in culture to explore which treatments are more effective on tumours with changes in the FBXW7 gene. This was not a clinical trial.

This research was part-funded by EveryCat Health Foundation, the CVS Group, Wellcome, the Natural Sciences and Engineering Research Council of Canada, and the Swiss National Science Foundation. A full acknowledgement list can be found in the publication.