Morbidity of Anogenital Disease
Types of HPV demonstrate a high degree of site specificity, with some HPV types only found on certain parts of the skin or mucous membranes. The overall prevalence of HPV in women is 22-35%. In men, the prevalence is 2-35% depending on the sexual practices of the population being studied.
HPV infection alone does not cause malignant transformation of infected tissue. Cofactors, such as tobacco use, ultraviolet radiation, pregnancy, folate deficiency, and immune suppression, have been implicated in this process. Patients receiving immunosuppressive drugs and patients with defects in cell-mediated immunity, including those infected with HIV are especially susceptible to developing HPV infections.
A direct correlation exists between anogenital HPV infection and measures of sexual activity, such as the age of first intercourse and the lifetime number of sexual partners. The prevalence of anogenital mucosal HPV infections is highest among college-aged women and men. The incidence of high-risk HPV infections drops after age 20-24 years, and the incidence of low-risk HPV types plateaus after age 30-39 years.
Women with a history of a cervical high-grade squamous intraepithelial lesion (HGSIL) or invasive squamous cell carcinoma (SCC) of the cervix are at increased risk for subsequent development of invasive cancer in other tissues of the anogenital/mucosal category, particularly vaginal and anal carcinoma. In these patients, the relative risk of vaginal carcinoma is 5.6, and the risk of anal carcinoma is 4.
Anal cancer has been strongly associated with male homosexuality and specific male practices, such as engaging in receptive anal intercourse. Relative risk is 33. However, the overall disease prevalence is higher in women than in men, with a female-to-male ratio of 1.5:1.
Patients who are immunosuppressed, particularly those with cutaneous malignant lesions, have a much higher incidence of