Initial Experience with Topical Fluorouracil for Treatment of HIV-Associated Anal Intraepithelial Neoplasia

Exposure to high-risk strains of human papillomavirus (HPV) promotes cellular dysplasia of the anal canal epithelium, potentially leading to anal intraepithelial neoplasia (AIN), which is in turn a precursor to invasive squamous cell carcinoma of the anus (SCCA). People with HIV Infection who engage in anoreceptive intercourse are at heightened risk for acquiring HPV, AIN, and SCCA. Although intravenous 5-fluorouracil (5-FU) is commonly used for treatment of invasive SCCA, there has been little experience with the use of topical 5-FU as therapy for AIN. We retrospectively reviewed records of the first 11 HIV-positive patients treated with topical 5-FU in our anal dysplasia clinic. Six (55%) patients had clinical improvement with reduction in area of dysplasia seen on high-resolution anoscopy (HRA). Three (27%) patients had improvement in AIN pathologic grade. Eight (73%) patients reported mild-to-moderate perianal irritation, which led six to reduce the frequency of 5-FU application. Further study of topical 5-FU for treatment of HIV-associated AIN is warranted.