Long-term Outcome of Ablation of Anal High-grade Squamous Intraepithelial Lesions

Abstract

High-grade dysplasia is the anal carcinoma precursor. Clinicians ablate high-grade dysplasia with laser, electrocautery, and infrared coagulation to prevent cancer. The aim of this study was to determine the long-term effectiveness of high-grade dysplasia ablation and the incidence of cancer. This study is a retrospective chart review of patients who were treated for high-grade dysplasia from February 1998 until May 2012. This study was conducted in a surgical practice screening patients for anal cancer and high-grade dysplasia. The patients identified were HIV-positive and -negative men who have sex with men. The ablation of high-grade dysplasia was performed. The primary outcomes measured were the probability of high-grade dysplasia recurrence postablation and the incidence of cancer. 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%). 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. 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.