Human malignancies associated with persistent HPV infection.

Human papillomavirus (HPV)-associated malignancies account for ~5% of human cancers worldwide. Thirteen, or more, HPV types are oncogenic, but infection with these viruses is common and usually cleared within 2 years. Only infections that become persistent are associated with the development of cancer, often occurring several decades later. These cancers mostly arise in 6 different anatomical regions: 5 are anogenital (anus, cervix, penis, vagina, and vulva) and the sixth is the oropharynx. Oncogenic HPVs promote cellular proliferation and genomic instability, but the anatomical niche of the target tissue also plays an important role in the development of cancer. Cells that reside in transitional regions between different types of epithelia, such as in the anus, cervix, and oropharynx, are particularly vulnerable to oncogenesis.