A Prospective, Dual-Center Trial of Circumferential Radiofrequency Ablation of Anal High-Grade Squamous Intraepithelial Lesions Demonstrate Improved Long-term Efficacy Over Historical Controls of Targeted Ablation

BACKGROUND: Targeted ablation of anal canal high-grade dysplasia results in high recurrence over time. Circumferential radiofrequency ablation might decrease recurrence. OBJECTIVE: This study aimed to determine the safety and efficacy of circumferential radiofrequency ablation for anal high-grade dysplasia. DESIGN: This was a dual-center, prospective trial of circumferential radiofrequency ablation with a 1-year follow-up with longer follow-up data abstracted from medical records of study patients returning after trial for surveillance. Ten participants from the identically conducted pilot circumferential radiofrequency ablation trial were included to improve sample size for longer-term analysis. SETTINGS: This study included 3 surgeons at 2 sites. PATIENTS: The study included 51 patients undergoing circumferential radiofrequency ablation for anal canal high-grade dysplasia. INTERVENTION: Circumferential radiofrequency ablation of anal canal high-grade dysplasia and targeted radiofrequency ablation of recurrence. MAIN OUTCOME MEASURES: The primary outcome measures were circumferential radiofrequency ablation efficacy and associated morbidity. RESULTS: Fifty-one participants underwent circumferential radiofrequency ablation but 48 participants returned for 1 or more postprocedure high-resolution anoscopy and were evaluable. The mean age of participants was 43 years, most were male (94%), 33% were living with HIV, and 58% had 3 or more high-grade dysplasias treated. Sixty percent had no recurrence, whereas 19% had 1 recurrence, 15% had 2 recurrences, and 6% had 3 recurrences. Most recurrences (66%) developed within the first 6 months. Kaplan-Meier probability of recurrence combining both series was 19% at 3 months, 30% at 6 months, and approximately 40% after 6 months out to 30 months. Most common morbidities were pain (85.4%) lasting for a median of 21 (range, 4-91) days and bleeding (91%) lasting for a median of 21 (range, 5-87) days. Of those with pain and bleeding, 65% and 85%, respectively, described it as mild. No patients developed fistulas, stricture, or incontinence. No serious adverse events related to circumferential radiofrequency ablation occurred. Having a previous recurrence was the only significant predictor of a subsequent recurrence (HR, 28.53) for recurrence at 9 months or before. LIMITATIONS: Enrollment ended prematurely, 10 participants from the pilot study were combined to increase the sample size, and longer-term follow-up was collected retrospectively were the limitations of this study. CONCLUSIONS: Circumferential radiofrequency ablation has improved efficacy over targeted ablation but with increased pain and bleeding.