The Presence of p16CDKN2A Protein Immunostaining Within Feline Nasal Planum Squamous Cell Carcinomas Is Associated With an Increased Survival Time and the Presence of Papillomaviral DNA

Abstract

In humans, oral SCCs are either caused by papillomavirus (PV) infection or by other carcinogens such as tobacco. As these 2 groups of SCCs have different causes they also have different clinical behaviors. Immunostaining using anti-p16CDKN2A protein (p16) antibodies is used to indicate a PV etiology in human oral SCCs and p16-positive SCCs have a more favorable prognosis. The present study investigated whether p16 immunostaining within feline nasal planum SCCs was similarly associated with the presence of PV DNA and with a longer survival time. Intense p16 immunostaining was visible in 32 of 51 (63%) SCCs. In 30 cats with nonexcised SCCs, cats with p16-positive neoplasms had a longer estimated mean survival time (643 days) than cats with p16-negative SCCs (217 days, P =.013). Papillomavirus DNA was amplified more frequently from p16-positive nasal planum SCCs (28 of 32) than p16-negative SCCs (5 of 19, P