ANAL SQUAMOUS INTRAEPITHELIAL LESIONS IN HIV-POSITIVE AND HIV-NEGATIVE HOMOSEXUAL AND BISEXUAL MEN - PREVALENCE AND RISK-FACTORS

Anal cancer is more commonly found in homosexual and bisexual men than cervical cancer is in women. Invasive anal cancer may be preceded by anal squamous intraepithelial lesions (ASIL), and treatment of ASIL ma y prevent the development of anal cancer. We characterized the prevale nce and risk factors for ASIL in 346 HIV-positive and 262 HIV-negative homosexual men. Anal cytology, biopsy of visible anal lesions, and hu man papillomavirus (HPV) tests were performed, and data on HIV serosta tus, CD4 count, and medical and lifestyle history were collected. ASIL was diagnosed in 36% of HIV-positive men and 7% of HIV-negative men ( relative risk [RR] = 5.7; 95% confidence interval [CI], 3.6-8.9). Amon g HIV-positive men, the RR for ASIL increased with lower CD4 levels bu t was elevated even in men with CD4 levels >500/mm(3) (RR = 3.8; 95% C I, 2.1-6.7) when compared with HIV-negative men. High-level HPV infect ion, as measured by detection of both hybrid capture (HC) group A and group B types, was another significant risk factor for ASIL in both HI V-positive men (RR = 8.8; 95% CI, 2.3-35) and HIV-negative men (RR = 2 0; 95% CI, 5.5-71) when compared with HIV-negative men. HIV-negative m en with anal HPV infection and HIV-positive men, regardless of CD4 lev el, are at high risk for ASIL.