Detection of alpha-human papillomavirus types in cutaneous squamous cell carcinoma associated with markers of carcinogenesis: a retrospective study

BACKGROUND: While the role of oncogenic alpha-human papillomavirus (α-HPV) types in anogenital and oral mucosal cancers is well established, their involvement in skin carcinogenesis remains unexplored. OBJECTIVES: To investigate the role of α-HPV in cutaneous squamous cell carcinoma (cSCC). METHODS: This retrospective study included 129 formalin-fixed, paraffin-embedded cSCC samples. The main outcomes were the proportion of α-HPV-positive cSCCs and the characterization of viral features, assessed through HPV typing and viral DNA integration analysis. RESULTS: The study included 99 cases of invasive cSCCs and 30 cases of Bowen disease. HPV DNA was detected in 56.6% of samples. HPV from the alpha genus was identified in 25 samples (19.4%), with only a single α-HPV type detected in each positive sample. HPV16 was the main type, detected in 10 samples. Peripheral healthy skin tested negative in 10 out of 11 α-HPV-positive samples. Viral DNA was integrated into host-cell DNA in eight of nine HPV16-positive samples. CONCLUSIONS: This study highlights a significant prevalence of α-HPV-positive samples among both invasive and in situ cSCC. The virological findings support a carcinogenic role of α-HPV in cSCC.