HPV-positive cancers at uncommon sites: a narrative review

Human papillomavirus (HPV) usually infects the anogenital and the oropharyngeal areas. HPV may lead to cancer at these sites, most notably at the uterine cervix. Less frequently, vaginal, vulvar, anal and penile cancers may also arise. HPV may be also found, sometimes, in other cancers, such as lung, breast, bladder, esophageal cancers and others, which are not typical sites for HPV-related cancers. HPV spreads easily throughout the body and it has an intrinsic carcinogenic potential, which it may operate on organs which are distant from the genital area, although with a limited incidence of disease. It has been debated whether such occurrence has a casual or causative significance. In this systematic review we summarize the evidence and the pitfalls of these uncommon HPV-positive cancers, with particular emphasis on HPV genotypes distribution.