Relationship of papillomaviruses to anogenital cancer.

A variety of HPV types infect the anogenital mucosa, giving rise to lesions that differ in clinical appearance, histology, and their risk of malignant progression. HPV-16 is distinguished by a strong association with high-grade intraepithelial neoplasia and the greatest prevalence in anogenital malignancy. Most cancers appear to have a multifactorial etiology, and HPV infection alone is probably insufficient for malignant transformation. However, the consistent association between HPV infection and anogenital cancers emphasizes that the sexually transmitted papillomaviruses may have a necessary role in carcinogenesis. Hence, there is a prospect that vaccination programs may one day allow public health control of HPV infection, thereby eliminating an important risk factor.