Anal cancer and screening guidelines for human papillomavirus in men.

The association between human papillomavirus (HPV) and anal cancer and the similarities between the "transitional zones" within the cervix and anus have raised questions regarding the medical biology of anal cancer. In recent years, increased rates of HPV infection and anal cancer among men have encouraged the medical community to search for causes and ways to identify the less insidious precursor, anal intraepithelial neoplasia. The "alphabet soup" terminology describing anal cytologic findings obtained by Papanicolaou (Pap) tests and the anal histologic findings obtained from biopsy specimens need to be better understood as distinct entities. Risk factors for the development of anal cancer have been identified and should be discussed with patients--especially those infected with human immunodeficiency virus--who have a much higher than normal risk of anal cancer. The anal Pap test has been used by the Northwest Pennsylvania Rural AIDS Alliance to detect potential precursors to cancer and degrees of anal dyplasia in patients with HIV infection. The Alliance has been instrumental in creating guidelines for anal Pap testing and encouraging other medical professionals and clinics to do the same, and these guidelines are provided herein.