The Association Of Felis Catus Papillomavirus Type 2 Infection In Feline Cutaneous Squamous Cell Carcinomas And Its Premalignant Lesions (Bowenoid In Situ Carcinoma And Actinic Keratosis)

Abstract

Feline cutaneous squamous cell carcinomas (SCC) are the most common cutaneous malignant skin neoplasms of cats, comprising approximately 15% of feline skin neoplasms. Previous studies have demonstrated a potential causative role of infection with feline papillomaviruses, in particular Felis catus papillomavirus type-2 (FcaPV-2), in the development of cutaneous SCCs and its premalignant lesion Bowenoid in situ carcinoma (BISC). More recent studies in the human literature have also suggested a potential role of human papillomavirus (HPV) in the development of another premalignant skin lesion actinic keratosis (AK). The IHC study demonstrated that feline BISCs exhibited positive p16 labelling at higher rates compared to AKs (p = 0.0030) but there was no statistically significant difference in p16 labelling between UV-exposed and UV-protected SCCs (p = 0.0593). IHC for p53 was unsuccessful. The qPCR study demonstrated that UV-protected SCCs were more likely to contain FcaPV-2 DNA compared to UV-exposed SCCs (p = 0.0095) but there were no statistically significant differences in viral DNA detection between BISCs and AKs (p = 0.9512). When IHC and qPCR results were combined together, no statistically significant difference was observed in FcaPV-2 aetiology (positive for both FcaPV-2 DNA by PCR and p16 labelling by IHC) between feline BISCs and AKs (p = 0.1723). However, there was a statistically significant difference observed in FcaPV-2 aetiology between UV-protected and UV-exposed cutaneous SCCs (p = 0.0236). Therefore, FcaPV-2 infection appears to be associated with the development of BISCs, AKs, and UV-protected SCCs but not UV-exposed SCCs. This is suggestive that FcaPV-2 infection may be involved in the development of more cutaneous lesions in felines than what is currently expected.