Phase I Study Demonstrates Safety and Tolerability of Radiofrequency Ablation (RFA) of the Anal Mucosa

Abstract

Background Anal carcinoma is increasing in high-risk populations. Dysplasia is often distributed throughout the anal mucosa, and focal ablative techniques have high rates of recurrence. Methods With the goal of eradicating dysplasia from the entire anal mucosa, we conducted a phase I dose-ranging study to determine the safety and tolerability of radiofrequency ablation (RFA). HIV-infected individuals with high-grade anal intraepithelial neoplasia underwent RFA of the anal mucosa. Patient-reported procedural and postprocedural symptoms were recorded, and mucosal healing was visually assessed. Results Four groups of 3 subjects each were treated with incrementally increasing numbers of RF pulses (1-3) applied to a single area of anal mucosa. Two or three doses of 12 J/cm2 were found to have acceptable patient tolerance and healing of the mucosa within 4 weeks of ablation. Using these doses, 2 groups underwent ablation of 180° of contiguous mucosa. Subjects experienced a loss of 1 to 3 days of daily activities of living, 7 to 14 days of postprocedure symptoms, and mucosal healing within 4 weeks. One subject in the first treatment group had the procedure aborted due to severe procedural pain. Conclusions The study provides evidence of the safety and tolerability of anal RFA of 180° of contiguous mucosa in a single procedure and will allow future RFA efficacy studies in the treatment of anal dysplasia.