An international team of veterinary and human-cancer researchers has produced the largest genetic map yet of tumors in domestic cats, finding that many of the mutations driving feline cancers closely mirror those found in human disease. The study, published in the journal Science, was led by researchers at the University of Guelph and the University of Bern.
The team sequenced paired tumor and healthy tissue from 493 pet cats across five countries, drawing on samples that veterinarians had already collected for routine diagnostic biopsies rather than performing new invasive sampling. Across 13 tumor types, researchers screened roughly 1,000 genes with known counterparts in human cancer. TP53, one of the most commonly disrupted genes in human tumors, was also the most frequently mutated gene in the cat samples, appearing in about a third of them. The analysis identified 31 likely cancer-driving genes, along with recurring mutational patterns and inherited variants that appear to raise cancer risk. More than half of feline mammary tumors carried mutations in FBXW7, a pattern that echoes a subset of human breast cancers.
A model with limits
Cats and dogs share human households, diets and environmental exposures, which has made them useful as sentinel species for studying real-world cancer risk. Shorter feline lifespans also let researchers observe cancer's progression on a faster timeline than is possible in people. But the new data also show where the cat genome diverges: RAS-family mutations, common drivers in many human cancers, were essentially absent from the feline tumors, a reminder that the two species' cancers are similar, not identical.
Researchers involved in the project described the scale of the resource as unusual for veterinary oncology.
"Having access to such a large set of donated tissues allowed us to assess drug responses across tumour types, in a way that hasn't been possible at this scale before."
Sven Rottenberg, co-senior author, University of Bern
The paper's authors are careful to flag that its drug-sensitivity findings, including evidence that FBXW7-mutant tumor cells responded strongly to a class of chemotherapy drugs called vinca alkaloids, come from laboratory tissue-culture experiments rather than from cats or people undergoing treatment. The study is also retrospective and drew on cats already brought to veterinary clinics, a sampling approach that likely skews toward certain breeds, regions and owners with access to veterinary diagnostics, and the genetic overlaps documented do not by themselves prove that a drug effective against one species' tumor will work in the other.
The researchers say the dataset lays groundwork for what they call precision feline oncology, and for future comparative trials in which treatments tested in cats with naturally occurring cancer could help inform, or be informed by, human clinical research.
