Human papillomaviruses and the skin: more to be learned.

Abstract

That papillomaviruses can cause skin cancer has been known for almost 70 years, after Peyton Rous and colleagues reported the malignant conversion of persistent rabbit skin warts induced by the Shope cottontail rabbit papillomavirus. The relationship between human papillomaviruses (HPV) and basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) of the skin is an important issue since non-melanoma skin cancer (NMSC) is the most common form of malignancy among fair-skinned populations. Moreover, immunosuppressed organ transplant recipients are at high risk of developing NMSC, especially SCC. It is well established that solar ultraviolet radiation (UVR) is the major risk factor, acting through both mutagenic and immunosuppressive effects. Cutaneous SCC, developing in patients suffering from epidermodysplasia verruciformis (EV), a rare genodermatosis associated with a high risk of skin cancer, provided the evidence for a role of specific HPV types in human cancer (reviewed inOrth, 1987). But the role of HPV in premalignant lesions of the skin (actinic keratosis, Bowen's disease) and in NMSC in the general population or upon immunosuppression is still a matter of debate (reviewed inHarwood and Proby, 2002;Pfister, 2003).