Cat Tumors Share Genetic Signatures with Human Cancers, Genome Sequencing of 500 Pet Felines Revealed

Genetic analyses of pet cats with cancer reveal similarities to human tumors that may help advance feline precision oncology.

Cancer commonly occurs in companion animals such as cats and dogs. In recent years, researchers’ understanding of dog tumors on a molecular level has significantly progressed, but they still didn’t know much about tumors in cats—until now.

Recently, Louise van der Weyden, a cancer geneticist at Wellcome Sanger Institute, and her colleagues analyzed DNA from nearly 500 pet cats with cancer.¹ They discovered several genetic signatures that resemble human tumors, for example, how commonly the tumor protein 53 gene (TP53) is mutated. These similarities, which the researchers reported in Science, suggest that pet cats may benefit from certain cancer treatments which are already available to human patients.

In the study, the researchers sequenced 493 pairs of cancerous and healthy tissues from pet cats. Their analysis spanned 13 tumor types and focused on the feline orthologs of approximately 1,000 cancer-associated genes in humans.

The researchers identified 31 cancer driver genes that were mutated in more than one sample. Five, including classic human tumor suppressor genes such as TP53, phosphatase and tensin homolog (PTEN), and F-box and WD repeat domain-containing 7 (FBXW7), were drivers in multiple tumor types.

The most frequently mutated gene, TP53, was altered in about 33 percent of all tumors that the researchers analyzed. This rate is comparable to one that others previously reported in a human pan-cancer study: 34 percent.² Similarly, 20 percent of cat tumors in the study had lost PTEN, and a past study showed that the gene was deleted in 25 percent of human cancers.³ These trends establish potentially actionable similarities between human and feline cancers.

To test whether human drugs could indeed be useful for pet cats with cancer, the researchers treated three-dimensional feline breast cancer organoids, or tumoroids, with human chemotherapy drugs such as vincristine and vinorelbine. They found that certain FBXW7 mutations made the cat tumoroids more sensitive to the drugs, supporting the researchers’ hypothesis that existing human chemotherapy drugs may also benefit their feline companions with cancer.

The scientists hope that their findings may serve as a resource for veterinary oncologists and help advance precision medicine for pet cats with cancer.