Ablation Outcomes for HIV-Infected and Uninfected Patients with Anal High-grade Squamous Intraepithelial Lesions (HSIL)

Background: HPV-induced anal HSIL, the putative anal cancer precursors, are highly prevalent in HIV-infected patients. Screening and ablation of anal HSIL has been proposed for high-risk patients but is associated with substantial recurrence rates. Using data from a large anal cancer-screening cohort, we evaluated long-term outcomes following HSIL ablation. Methods: 427 participants with HSIL were treated with electrocautery ablation. Using HRA, surveillance was conducted within 12 months to assess treatment response. HSILs in the same anatomic region as the index lesion were defined as persistent; HSILs in a different region were defined as metachronous. Results: Our cohort consisted of MSM (93%) and HIV+ persons (91%). HSIL persistence after ablation was 39% (95% CI: 34%-43%) and did not differ significantly by HIV status or sexual behavior. Metachronous HSIL was found in 27% (95% CI: 23%-31%). The overall recurrence (persistent plus metachronous) was 53% and was more frequent in HIV+ persons (56% vs. 28%; p=0.001). Subjects with more than one HSIL at baseline had a higher risk of persistence than those with solitary lesions (48% vs. 32%; p=0.001). No other factors were associated with persistence, including age, race/ethnicity, smoking, HIV viral load and CD4 count. After adjustment for baseline number of lesions, HIV infection was associated with overall recurrence of HSIL (odds ratio 3.2; 95% CI: 1.5–6.9). Conclusions: In our cohort, over one third of anal HSILs persisted after ablation. HIV+ patients with multiple HSILs at baseline are at a higher risk of recurrence and may require careful surveillance