Imiquimod, Fluorouracil, or Observation in Treating HIV-Positive Patients With High-Grade Anal Squamous Skin Lesions

Inclusion Criteria: * HIV-positive; documentation of HIV infection must be based on a federally approved, licensed HIV test performed in conjunction with screening (enzyme linked immunosorbent assay \[ELISA\], western blot, or other test); alternatively, this documentation may include a record that another physician has documented that the patient has HIV based on prior ELISA and western blot; an approved antibody test will be used to confirm diagnosis; if the physician is treating a patient with combination antiretroviral therapy (cART) with a history of HIV positivity based on an approved antibody test then repeat antibody confirmation is not necessary * Biopsy-proven HSIL (anal intraepithelial neoplasia 2 (AIN2) and/or AIN3) of the anal canal at either the squamocolumnar junction or distal anus, documented within 60 days prior to enrollment, but not less than 1 week prior to enrollment * HSIL occupies at least 25% of the circumference of the anal canal at either the squamocolumnar junction or distal anus on high-resolution anoscopy (HRA) at screening or entry based on available biopsy results and visual appearance * Anal HSIL lesions are visible at study entry and no lesions are suspicious for invasive cancer * Ability to understand and willing to provide informed consent * Participants must, in the opinion of the Investigator, be capable of complying with the requirements of this protocol including self-administration of study treatment * Karnofsky performance status of …