title: A trial of radiofrequency ablation for anal intraepithelial neoplasia.
abstract: OBJECTIVE
  Radiofrequency ablation (RFA) effectively treats esophageal high-grade dysplasia, but its efficacy in treating anal canal high-grade squamous intraepithelial lesions (HSILs) is unsubstantiated. This prospective study assessed the safety and efficacy of applying hemi-circumferential RFA to anal canal HSIL.
  
  
  METHODS
  Twenty-one HIV-negative participants with HSIL occupying ≤ half the anal canal circumference were treated with hemi-circumferential anal canal RFA. Participants were assessed every 3 months for 12 months with high-resolution anoscopy; recurrence in the treatment zone was re-treated with focal RFA.
  
  
  RESULTS
  Twenty-one participants with a mean of 1.7 lesions (range 1-4) enrolled and completed the trial. Six (29 %) participants had recurrent HSIL within the treated hemi-circumference within 1 year. Four participants (19 %) had persistence of an index lesion at 3 months. One (2.9 %) index HSIL persisted again at 12 months. No participants had more than two RFA treatments. KM curve-predicted HSIL-free survival within the treatment zone at 1 year was 76 % (95 % CI 52-89 %). Comparing the first 7 and last 14 participants, the predicted 1-year HSIL-free survivals are 43 % (95 % CI 10-73 %) and 93 % (95 % CI 59-99 %), respectively (p = 0.008), suggesting a learning curve with the treating physician. Multivariable analysis showed decreased recurrence in the last 14 participants (HR 0.02; 95 % CI 0.001-0.63) while increasing BMI increased recurrence (HR 1.43, 95 % CI 1.01-2.01). No participants had device or procedure-related serious adverse events, anal stricture, or heavy bleeding.
  
  
  CONCLUSIONS
  Hemi-circumferential RFA yielded a high rate of anal HSIL eradication in HIV-negative patients at 1 year with minimal adverse events. Lesion persistence was probably related to incomplete initial ablation.
authors: Massachusetts General Hospital, Boston, MA, USA.
authors: Robert N
authors: RN
authors: Goldstone
authors: Medtronic, Sunnyvale, CA, USA.
authors: Shirin R
authors: SR
authors: Hasan
authors: Medtronic, New Haven, CT, USA.
authors: Steven
authors: S
authors: Drury
authors: Departments of Pathology and Obstetrics, Gynecology and Reproductive Sciences, University of California San Francisco, San Francisco, CA, USA.
authors: Teresa M
authors: TM
authors: Darragh
authors: Department of Pathology, University of California San Francisco, San Francisco, CA, USA.
authors: Annemieke
authors: A
authors: van Zante
authors: Icahn School of Medicine, Mount Sinai, 420 West 23rd St, New York, NY, 10011, USA. goldstone.stephen@gmail.com.
authors: Stephen E
authors: SE
authors: Goldstone
mesh_terms: D000328:Adult; D000368:Aged; D001005:Anus Neoplasms / Q000601:surgery*; D002278:Carcinoma in Situ / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects; D003710:Demography; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D010149:Postoperative Pain / Q000209:etiology; D012307:Risk Factors; D016896:Treatment Outcome
keywords: Anal cancer; High-grade squamous intraepithelial lesion; Radiofrequency ablation