Prevalence and risk factors for anal squamous intraepithelial lesions in women

Background: Anal cancers are thought to arise from squamous intraepithelial lesions in the anal canal, and women infected with human immunodeficiency virus-1 (HIV) mag be at higher risk of anal cancer. Our aim was to determin e the prevalence of human papillomavirus (HPV)-related abnormalities of the anal canal in women and to characterize risk factors for these lesions, Me thods: We evaluated HPV-related abnormalities in 251 HIV-positive and in 68 HIV-negative women. We completed physical examinations and obtained questi onnaire data on medical history and relevant sexual practices. Univariate a nd adjusted relative risks (RRs) and 95% confidence intervals (CIs) were co mputed using the Mantel-Haenszel procedure and regression techniques, All s tatistical tests were two-sided, Results: Abnormal anal cytology, including atypical squamous cells of undetermined significance, low-grade squamous i ntraepithelial lesions, or high-grade squamous intraepithelial lesions (HSI Ls), was diagnosed in 26% of HIV-positive and in 8% of HIV-negative women. HSILs were detected by histology or cytology in 6% of HIV-positive and in 2 % of HIV-negative women. HIV-positive women showed increased risk of anal d isease as the CD4 count decreased (P < .0001) and as the plasma HIV RNA vir al load increased (P =.02), HIV-positive women with abnormal cervical cytol ogy had an increased risk of abnormal anal cytology at the same visit (RR = 2.2; 95% CI = 1.4 to 3.3). Abnormal anal cytology in HIV-positive women wa s associated with anal HPV RNA detected by the polymerase chain reaction an d by a non-amplification-based test (RR = 4.3; 95% CI = 1.6 to 11), In a mu ltivariate analysis, the history of anal intercourse and concurrent abnorma l cervical cytology also were statistically significantly (P =.05) associat ed with abnormal anal cytology. Conclusions: HIV-positive women had a highe r risk of abnormal anal cytology than did HIV-negative women with high-risk lifestyle factors. These data provide strong support for anoscopic and his tologic assessment and careful followup of women with abnormal anal lesions .