Science Digest: What factors predispose cats to squamous cell carcinoma?

10 February 2026

Squamous cell carcinomas (SCCs) are malignant epithelial neoplasms and are one of the most common tumours in cats. In cats, SCCs are primarily found in the skin and oral cavity; however, comparative research between these sites has been limited.¹ Determining which cats are more susceptible to SCCs at particular anatomical sites would allow more targeted clinical vigilance and inform diagnostic decisions.

A new study, published in Pets, presents the largest review to date on potential predispositions for SCC and whether they differ between oral (oSCC) and cutaneous (cSCC) forms.¹

Researchers retrospectively analysed 55,171 feline histopathology submissions from 2017 to 2023, collected by German diagnostic laboratory LABOKLIN GmbH & Co. KG. Age, breed, sex, coat length, sampling site, macroscopic findings, histological description, and diagnosis were standardised for statistical analysis.

A total of 4,300 cases were diagnosed as SCC. Affected cats were predominantly older, with a median age of 13 years and an estimated 21–22% increase in the risk of SCC per additional year of life. The authors suggest that this may be due to more prolonged cumulative exposure to carcinogens with age. However, very young cats were also affected, with 15 cats diagnosed under two years old, and the youngest being 5 months old. This shows that SCC must be considered as a differential diagnosis for oral and cutaneous lesions, even in kittens.

No breed predispositions were found. However, Persians, Norwegian Forest Cats, British Shorthairs, Chartreux, and Siamese cats showed a significantly reduced risk for SCC compared to non-pedigree cats. Longhaired cats also had a significantly lower risk of developing SCC compared to shorthaired cats, while hairless cats had an increased risk compared to shorthaired cats. No sex predisposition was identified.

Of the cats affected, 41% were diagnosed with oSCC and 36% were diagnosed with cSCC. Cats with oSCC were significantly older (median age 13 years) than those with cSCC (median age 12 years), but the effect size was small and the relevance is questionable.

Within the oral cavity, the most frequently affected sites were the gingiva (36%), tongue (19%), lip (2%), cheek mucosa (2%), palate (2%), pharynx (1%), tonsil (1%) and larynx (0.5%), with the site not reported in 37% of cases. Of the cutaneous sites, the most affected were the ear (35%), head and neck (9%), nose (8%), digits (7%), periocular skin and eyelids (7%), and the trunk (5%). Less commonly affected primary sites were the eyes, middle and inner ear, trachea, oesophagus, and salivary gland.

Coat type influenced the distribution of cutaneous localisation. Longhaired cats had higher frequencies of cSCC on the head and neck, the trunk, and multiple concurrent cSCC sites, but were less likely to have auricular cSCC compared with shorthaired cats. Hairless cats had an increased proportion of tumours on the trunk compared to shorthaired.

The dataset was subject to referral and submission bias, as it was based on records from a diagnostic laboratory, and only included cats with lesions deemed worthy of biopsy by clinicians and/or owners. It therefore doesn’t represent the general feline population. Oral SCC may have been overrepresented, due to increased diagnostic scrutiny in feline dental and oral disease.

Take home message

Squamous cell carcinomas should be considered a key differential for oral and cutaneous lesions, even in young cats. Age is the strongest predictor of feline SCC, with no sex or overall breed predisposition identified. However, Persians, Norwegian Forest Cats, Chartreux, and Siamese cats show a reduced risk for SCC, compared to non-pedigree cats.

Reference

¹Riedl A-C, Jensen KC, Schirl K, Hoffmann I, Schwinn J, Klopfleisch R & Aupperle-Lellbach H (2026) Squamous Cell Carcinomas in Cats: A Retrospective Study of 4300 Histopathological Cases (2017–2023). Pets. 3, 3. https://doi.org/10.3390/pets3010003