Human papillomaviruses as therapeutic targets in human cancer.

Cervical carcinomas are almost universally associated with high-risk human papillomavirus (HPV) infections, and are a leading cause of cancer death in women worldwide. HPV oncoproteins contribute to cancer initiation and progression and their expression is necessary for the maintenance of the transformed state. The fact that the initiating oncogenic insult, infection with a high-risk HPV and viral oncoprotein expression, is common to almost all cervical cancers offers unique opportunities for prevention, early detection, and therapy. The potential for prevention has been realized by introduction of prophylactic vaccines that are to prevent transmission of specific high-risk HPVs. Given, however, that these vaccines have no therapeutic efficacy and HPV-associated cervical cancers arise years if not decades after the initial infection, it has been estimated that there will be no measurable decline of HPV-associated tumors before 2040. Cervical cancer alone will be diagnosed in more than 375,000 US women between now and 2040. Other HPV-associated anogenital and head and neck cancers are predicted to afflict another 700,000 men and women over this time period. Hence, therapeutic efforts to combat high-risk HPV-associated disease remain of critical importance.