The role of papillomaviruses in anogenital cancer.

Humanpathogenic papillomaviruses (HPV) specifically types 16, 18, 31, 33, 35, 39, 45 and 52 have been linked to the etiology of anogenital cancer. Experimental evidence strongly supports a role of these virus types as causative agents for cancer of the cervix, vulva and penis. Although infection appears to be necessary for the development of malignant tumors, it is clearly not sufficient. Additional factors probably affecting host cell genes engaged in the control of HPV functions seem to be required for conversion of premalignant changes into invasive growth.