Long-Term Outcomes of Adding HPV Vaccine to the Anal Intraepithelial Neoplasia Treatment Regimen in HIV-Positive Men Who Have Sex with Men

Background.Recent evidence shows that quadrivalent human papillomavirus (qHPV) vaccination in men who have sex with men (MSM) who have a history of high-grade anal intraepithelial neoplasia (HGAIN) was associated with a 50% reduction in the risk of recurrent HGAIN. We evaluated the long-term clinical and economic outcomes of adding the qHPV vaccine to the treatment regimen for HGAIN in human immunodeficiency virus (HIV)-positive MSM aged ≥27 years. Methods.We constructed a Markov model based on anal histology in HIV-positive MSM comparing qHPV vaccination with no vaccination after treatment for HGAIN, the current practice. The model parameters, including baseline prevalence, disease transitions, costs, and utilities, were either obtained from the literature or calibrated using a natural history model of anal carcinogenesis. The model outputs included lifetime costs, quality-adjusted life years, and lifetime risk of developing anal cancer. We estimated the incremental cost-effectiveness ratio of qHPV vaccination compared to no qHPV vaccination and decrease in lifetime risk of anal cancer. We also conducted deterministic and probabilistic sensitivity analyses to evaluate the robustness of the results. Results.Use of qHPV vaccination after treatment for HGAIN decreased the lifetime risk of anal cancer by 63% compared with no vaccination. The qHPV vaccination strategy was cost saving; it decreased lifetime costs by $419 and increased quality-adjusted life years by 0.16. Results were robust to the sensitivity analysis. Conclusions.Vaccinating HIV-positive MSM aged ≥27 years with qHPV vaccine after treatment for HGAIN is a cost-saving strategy. Therefore, expansion of current vaccination guidelines to include this population should be a high priority.