Background: The objective of this study in MSM living with HIV was to determine the incidence of HSIL and ASCC, related factors, and the response to treatment.
Patients and methods: Data were gathered in 405 consecutive HIV-infected MSM (May 2010-December 2018) at baseline and annually on: sexual behavior, anal cytology, and HPV PCR and/or high-resolution anoscopy results. They could choose mucosectomy with electric scalpel (from May 2010) or self-administration of 5% imiquimod 3 times weekly for 16 weeks (from November 2013). A multivariate logistic regression model was developed for ≥HSIL-related factors using a step-wise approach to select variables, with a significance level of 0.05 for entry and 0.10 for exit, applying the Hosmer-Lemeshow test to assess the goodness of fit.
Results: The study included 405 patients with a mean age of 36.2 years; 56.7% had bachelor´s degree, and 52.8% were smokers. They had a mean of 1 (IQR 1-7) sexual partner in the previous 12 months, median time since HIV diagnosis of 2 years, and mean CD4 nadir of 367.9 cells/uL; 86.7% were receiving ART, the mean CD4 level was 689.6 cells/uL, mean CD4/CD8 ratio was 0.77, and 85.9% of patients were undetectable. Incidence rates were 30.86/1,000 patient-years for ≥high squamous intraepithelial lesion (HSIL) and 81.22/100,000 for anal squamous cell carcinoma (ASCC). The ≥HSIL incidence significantly decreased from 42.9% (9/21) in 2010 to 4.1% (10/254) in 2018 (p = 0.034). ≥HSIL risk factors were infection with HPV 11 (OR 3.81; 95%CI 1.76-8.24), HPV 16 (OR 2.69, 95%CI 1.22-5.99), HPV 18 (OR 2.73, 95%CI 1.01-7.36), HPV 53 (OR 2.97, 95%CI 1.002-8.79); HPV 61 (OR 11.88, 95%CI 3.67-38.53); HPV 68 (OR 2.44, CI 95% 1.03-5.8); low CD4 nadir (OR1.002; 95%CI 1-1.004) and history of AIDS (OR 2.373, CI 95% 1.009-5.577). Among HSIL-positive patients, the response rate was higher after imiquimod than after surgical excision (96.7% vs 73.3%, p = 0.009) and there were fewer re-treatments (2.7% vs 23.4%, p = 0.02) and adverse events (2.7% vs 100%, p = 0.046); none developed ASCC.
Conclusions: HSIL screening and treatment programs reduce the incidence of HSIL, which is related to chronic HPV infection and poor immunological status. Self-administration of 5% imiquimod as first-line treatment of HSIL is more effective than surgery in HIV+ MSM.