Abstract

More than 200 Human Papillomaviruses (HPV) have been officially established. Around 30 HPVs are mucosotropic and are distinguished in high-risk and low-risk genotypes according to their carcinogenic potential. HPV6 and 11 are not classifiable as to their carcinogenicity to humans, and are responsible for more than 90% of the ano-genital warts. For 12 HPVs (e.g., HPV16 and 18), there is instead sufficient evidence of their carcinogenicity in humans. They are the aetiological agents of cervical, vulvar, vaginal, penile, anal, as well as head and neck squamous cell carcinomas (SCC). HPV contribution to these neoplasias ranges between 25% and virtually 100% of cases according to the type of cancer. Up to 98% of anal SCCs (ASCC) diagnosed in men living with HIV are etiologically related to HPV. This virus also has a role in the development of oropharyngeal SCC (OPSCC). The proportion of OPSCCs attributable to HPV has been estimated to be 45% in Europe, but significant geographical differences exist. The substantial rise in ASCC and OPSCC incidence observed in recent years has fostered the interest on the burden of anal and oral HPV infection. The epidemiology of these infections will be outlined, along with an overview of the neoplastic lesions caused at the level of the anal canal and head and neck region. Finally, data on the time trend of ano-genital wart diagnoses will be provided, in light of the availability of the prophylactic vaccination for the prevention of HPV6 and 11 infections.