HIV-associated anal cancer.

HIV-associated anal carcinoma, a non-AIDS-defining cancer, is a human papillomavirus-associated malignancy with a spectrum of preinvasive changes. The standardized incidence ratio for anal cancer in patients with HIV/AIDS is 20-50. Algorithms for anal cancer screening include anal cytology followed by high-resolution anoscopy for those with abnormal findings. Outpatient topical treatments for anal intraepithelial neoplasia include infrared coagulation therapy, trichloroacetic acid, and imiquimod. The development of cost-effective national screening programs for HIV-associated anal cancer remains a challenge.