Background: Anal squamous cell carcinoma (SCC) incidence in men who have sex with men (MSM) is rising. The high-grade squamous intraepithelial lesion (HSIL) is purported to be a SCC precursor, but HSIL treatment remains controversial. We previously reported our experience with infrared coagulator (IRC) HSIL ablation in MSM with median follow-up of 1.5 years. We now report our long term results.

Methods: A retrospective chart review was performed on MSM with ≥1 IRC of intra-anal HSIL between 1999-2005. Included subjects had ≥1 yr additional follow-up with cytology, high-resolution anoscopy, and biopsy. New or recurrent HSIL was retreated.

Results: 96 MSM were enrolled (44 HIV+) with a median follow-up of 5.6 yrs (range 1-8.5) and 4 yrs (range 1-7.3) in HIV+ and HIV- MSM, respectively. HSIL recurred in 40 (91%) HIV+ and 32 (62%) HIV- MSM after first IRC and HIV+ MSM had a significantly shorter time to recurrence (p=0.013) (Figure 1). Median time to recurrence in HIV+ MSM was half that of HIV- MSM (1.0±0.1 yrs vs. 2.0±0.5 yrs, respectively). HIV+ MSM had significantly more HSILs compared to HIV- MSM at initial IRC (1.7 vs. 1.4, p=0.013), first recurrence (1.7 vs. 1.1, p=0.003), and second recurrence (0.9 vs. 0.5, p=0.038). On multivariable analysis, HIV was an independent risk factor for recurrence when adjusting for age, smoking status, and history of unprotected sex (HR=2.1, p=0.006). No MSM progressed to invasive SCC or experienced a serious adverse event. At last visit, 90% of HIV- MSM and 82% of HIV+ MSM were free of HSIL.

Conclusion: IRC is a safe office-based treatment for anal HSIL. Although recurrence is high, over 80% of MSM were free of HSIL at last visit. HSIL recurs more rapidly with more disease foci in HIV+ MSM compared to HIV- MSM. With repeated IRC no MSM progressed to cancer.