Background. As HIV-infected men live longer, rates of anal cancer have risen and antiretroviral therapy may not be protective. Anal human papillomavirus (HPV) infection prevalence has been estimated as high as 57% in HIV-negative men who have sex with men (MSM) and 88% in HIV-positive MSM populations. Approaches to screening and understanding of HPV-driven malignant transformation leading to anal cancer in this population are informed by experience with cervical cancer. We present data from the only Department of Defense Infectious Diseases (ID) anal dysplasia screening program.
Methods. Naval Medical Center San Diego ID clinic provides care to 600 HIV-positive men. In 2013, we began screening with anal Papanicolaou (Pap) smear and referred any abnormal results for high resolution anoscopy (HRA), performed by an ID attending. Anal Paps were repeated at the time of HRA. Using clinic records (paper and electronic), as well as information gathered from pre-procedural questionnaires regarding social history, data were compiled for each patient.
Results. To date, 78 patients have been evaluated with HRA. Average age was 42 years, duration of HIV infection 10 years, and CD4 nadir 284 cells/µL. Average CD4 nadirs were 400 cells/µL, 284 cells/µL, 285 cells/µL, 188 cells/µL for those with no dysplasia, Atypical Squamous Cells of Undetermined Significance (ASCUS), Low Grade Squamous Intraepithelial Lesion (LGSIL), and High Grade Squamous Intraepithelial Lesion (HGSIL), respectively. Of those with low grade cytology (ASCUS or LGSIL), 20% had high grade Anal Intraepithelial Neoplasia (AIN) II or III; negative predictive value of low grade cytology for AIN II or III was 77%. Of those with high grade cytology (HGSIL), 100% had AIN II or III, and one clinically early case of anal squamous cell carcinoma was identified.
Conclusion. In our first year, we've demonstrated the feasibility, utility, and importance of anal dysplasia surveillance in an HIV-infected population. Additional data are needed in order to link observation and intervention to clinical outcomes and will help to clarify natural history of dysplasia as well as help guide appropriate follow-up. Further, our experience provides a model to be considered by other ID and HIV clinics interested in starting anal dysplasia surveillance programs.
Disclosures. All authors: No reported disclosures.