Efficacy and Safety of TCA vs. ECA for the Treatment of AIN in HIV-positive Patients

Anal human papillomavirus (HPV)-infection and HPV-induced AIN, an anal cancer precursor, are very frequent in HIV-positive patients (HIV+), especially in men who have sex with men (MSM), but also in women. Consequently, HIV+ have a strongly increased risk for anal cancer. Screening for and treatment of AIN are recommended in HIV+, although only two RCT on AIN treatment have been published. We plan a multicenter, unblinded, non-inferiority RCT that evaluates the efficacy and safety of 2 high-resolution anoscopy (HRA)-guided treatment options for AIN: topical application of trichloroacetic acid (TCA) and surgical treatment with electrocautery (ECA). ECA was the best option for intra-anal AIN in a recent randomized controlled trial (RCT). TCA, an inexpensive and established therapy for genital warts, has been evaluated for AIN only in a retrospective pilot study that showed clearance rates comparable to those found for ECA, with possibly less adverse events (AE). Our primary hypothesis is that cost-saving and simple TCA is non-inferior to ECA. 2800 HIV+ will be screened by HRA in 9 proctological centers and 560 HIV+ with histologically confirmed intra-anal AIN will be randomized (1:1) to receive up to 4 treatments with TCA or ECA within 12 weeks. The primary efficacy endpoint is clinical (HRA) and histological resolution of AIN 4 weeks after the last treatment. Secondary endpoints comprise recurrence of AIN 24 weeks after end of therapy, the number of interventions, AE, and the influence of HPV parameters such as anal HPV-types, viral load and HPV-oncogene-mRNA.