Long-term Outcome of Ablation of Anal High-grade Squamous Intraepithelial Lesions: Recurrence and Incidence of Cancer

Abstract

BACKGROUND: High-grade dysplasia is the anal carcinoma precursor. Clinicians ablate high-grade dysplasia with laser, electrocautery, and infrared coagulation to prevent cancer. OBJECTIVE: The aim of this study was to determine the long-term effectiveness of high-grade dysplasia ablation and the incidence of cancer. DESIGN: This study is a retrospective chart review of patients who were treated for high-grade dysplasia from February 1998 until May 2012. SETTING: This study was conducted in a surgical practice screening patients for anal cancer and high-grade dysplasia. PATIENTS: The patients identified were HIV-positive and -negative men who have sex with men. INTERVENTION: The ablation of high-grade dysplasia was performed. MAIN OUTCOME MEASURES: The primary outcomes measured were the probability of high-grade dysplasia recurrence postablation and the incidence of cancer. RESULTS: Four hundred fifty-six HIV-positive men who have sex with men (mean age, 45 ± 9 years) and 271 HIV-negative men who have sex with men (mean age, 41 ± 11 years) followed for a median of 2.2 (range, 0.2-13) years underwent high-grade dysplasia ablation by laser, infrared coagulation, and/or electrocautery. Median time to recurrence was 6.8 and 6.9 months for HIV-positive and -negative patients. Kaplan-Meier curves predict a rate of recurrence 1 year after the first ablation for HIV-positive and -negative patients of 53% (95% CI, 49%-58%) and 49% (95% CI, 43%-55%). At 2 and 3 years, the rate of recurrence was 68% (95% CI, 63%-73%) and 77% (95% CI, 7%2-82%) for HIV-positive patients and 57% (95% CI, 51%-64%) and 66% (95% CI, 59%-73%) for HIV-negative patients. The median number of recurrent lesions was ≤2 for HIV-positive patients and ≤1 for HIV-negative patients. Recurrence increased with HIV infection (HR, 1.3; 95% CI, 1.1-1.6) and each additional lesion treated (HR 1.6, 95% CI, 1.1-1.2). Five HIV-positive men who have sex with men developed cancer. The Kaplan-Meier probability of cancer 3 years postablation was 1.97% (95% CI, 0.73%-5.2%). LIMITATIONS: This is a retrospective study by 1 surgeon who has extensive experience treating anal dysplasia. There was no pathology review, and the type of recurrence cannot be definitively determined because the location could be inaccurate. CONCLUSIONS: Patients undergoing ablation of intra-anal high-grade dysplasia have high recurrence, but the probability of developing anal cancer is low. HIV infection and increased number of high-grade dysplasias increases the risk of recurrence.