title: Prevalence and predictors of high-grade anal intraepithelial neoplasia in a community-based sample of homosexual men.
abstract: BACKGROUND
  We report the prevalence and predictors for high-grade anal intraepithelial neoplasia (HGAIN) in community-based cohorts of HIV-negative and HIV-positive homosexual men in Sydney, Australia.
  
  
  METHODS
  A cross-sectional study of consecutive participants in both cohorts was performed in 2005 (204 HIV-negative and 128 HIV-positive men). Anal swabs collected by a research nurse underwent cytological analysis, using the ThinPrep procedure, and human papillomavirus (HPV) testing. Participants who had cytological abnormalities other than low-grade squamous epithelial lesions (SIL) were referred for high resolution anoscopy (HRA).
  
  
  RESULTS
  A total of 114 men had cytological abnormalities (24.3% of HIV-negative and 57.5% of HIV-positive men, odds ratio (OR)=4.21, 95% confidence interval (CI) 2.57-6.90). However, only three (2.3%) HIV-positive men and no HIV-negative men had high-grade SIL on anal cytology. Seventy-seven men were referred for HRA, of whom 63 (81.8%) attended. Histologically confirmed HGAIN was detected in 21 (33.3%). The prevalence of HGAIN was higher in HIV-positive men (10.8%) than in HIV-negative men (5.0%, OR=2.29, 95% CI 0.93-5.63, P=0.071). HGAIN was not related to age but was strongly associated with the detection of high-risk types of anal HPV (OR=10.1, 95% CI 1.33-76.2) rather than low-risk types (OR=1.97, 95% CI 0.74-5.25).
  
  
  CONCLUSIONS
  HGAIN was prevalent in homosexual men across all age groups and was more than twice as common in HIV-positive men compared with HIV-negative men. The presence of high-risk anal HPV was highly predictive of HGAIN.
authors.affiliation: Sexually Transmitted Infections Research Centre, University of Sydney, Marion Villa, Westmead, Australia.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Hillman
authors.forename: Marina T
authors.initials: MT
authors.lastname: van Leeuwen
authors.forename: Claire M
authors.initials: CM
authors.lastname: Vajdic
authors.forename: Leo
authors.initials: L
authors.lastname: McHugh
authors.forename: Garrett P
authors.initials: GP
authors.lastname: Prestage
authors.forename: Leon P
authors.initials: LP
authors.lastname: Botes
authors.forename: Iryna
authors.initials: I
authors.lastname: Zablotska
authors.forename: Gabriele
authors.initials: G
authors.lastname: Medley
authors.forename: Sepehr N
authors.initials: SN
authors.lastname: Tabrizi
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Grulich
authors.forename: Fengyi
authors.initials: F
authors.lastname: Jin
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000453:epidemiology; D000328:Adult; D000368:Aged; D001005:Anus Neoplasms / Q000175:diagnosis* / Q000453:epidemiology* / Q000517:prevention & control; D001315:Australia / Q000453:epidemiology; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000453:epidemiology; D015984:Causality; D015897:Comorbidity; D018451:Homosexuality, Male / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D008297:Male; D008403:Mass Screening / Q000706:statistics & numerical data; D008875:Middle Aged; D030361:Papillomavirus Infections / Q000175:diagnosis* / Q000453:epidemiology* / Q000517:prevention & control; D012309:Risk-Taking; D019529:Sexuality / Q000706:statistics & numerical data*