Elements of an anal dysplasia screening program.

The incidence of anal cancer in HIV-infected men who have sex with men (MSM) is highly elevated compared to the general population, as is the incidence of its precursor lesion, high-grade anal intraepithelial neoplasia (HGAIN). MSM in general and other immunocompromised populations are also at higher risk. Treatment of HGAIN may prevent development of cancer, similar to the decrease in cervical cancers that has occurred since the advent of cervical cancer screening programs in women. Cervical cancer screening tools have been adapted and validated for screening, diagnosis, and treatment of anal HGAIN. Anal cancer screening programs have now been available for more than a decade, although they are not yet standards of care. Incorporating screening procedures into practice depends on the available resources in a particular community. This article discusses the procedures for anal cancer screening including cytology, digital anal rectal examinations, high-resolution anoscopy, and biopsy.