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) may be at higher risk of anal cancer. Our aim was to determine the prevalence of human papillomavirus (HPV)-related abnormalities of the anal canal in women and to characterize risk factors for these lesions.


METHODS
We evaluated HPV-related abnormalities in 251 HIV-positive and in 68 HIV-negative women. We completed physical examinations and obtained questionnaire data on medical history and relevant sexual practices. Univariate and adjusted relative risks (RRs) and 95% confidence intervals (CIs) were computed using the Mantel-Haenszel procedure and regression techniques. All statistical tests were two-sided.


RESULTS
Abnormal anal cytology, including atypical squamous cells of undetermined significance, low-grade squamous intraepithelial lesions, or high-grade squamous intraepithelial lesions (HSILs), 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 disease as the CD4 count decreased (P<.0001) and as the plasma HIV RNA viral load increased (P =.02). HIV-positive women with abnormal cervical cytology 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 was associated with anal HPV RNA detected by the polymerase chain reaction and by a nonamplification-based test (RR = 4.3; 95% CI = 1.6 to 11). In a multivariate analysis, the history of anal intercourse and concurrent abnormal cervical cytology also were statistically significantly (P =.05) associated with abnormal anal cytology.


CONCLUSIONS
HIV-positive women had a higher risk of abnormal anal cytology than did HIV-negative women with high-risk lifestyle factors. These data provide strong support for anoscopic and histologic assessment and careful follow-up of women with abnormal anal lesions.
Holly
E A
EA
Department of Epidemiology and Biostatistics, University of California, San Francisco 94143-1228, USA. eaholly@epi.ucsf.edu
Ralston
M L
ML
Darragh
T M
TM
Greenblatt
R M
RM
Jay
N
N
Palefsky
J M
JM
D000328:Adult; D001003:Anal Canal / Q000473:pathology; D000704:Analysis of Variance; D001005:Anus Neoplasms / Q000453:epidemiology*; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology*; D016001:Confidence Intervals; D004522:Educational Status; D005006:Ethnicity; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000453:epidemiology; D018023:HIV Seronegativity; D006679:HIV Seropositivity / Q000453:epidemiology; D006801:Humans; D007182:Income; D017533:Marital Status; D008487:Medical History Taking; D008875:Middle Aged; D027383:Papillomaviridae / Q000302:isolation & purification; D030361:Papillomavirus Infections / Q000150:complications* / Q000453:epidemiology; D015995:Prevalence; D044469:Racial Groups; D012044:Regression Analysis; D012306:Risk; D012307:Risk Factors; D012495:San Francisco / Q000453:epidemiology; D012725:Sexual Behavior; D012959:Socioeconomic Factors; D019966:Substance-Related Disorders / Q000453:epidemiology; D011795:Surveys and Questionnaires; D014412:Tumor Virus Infections / Q000150:complications / Q000453:epidemiology