title: Preliminary results of a screening program for anal cancer and its precursors for HIV-infected men who have sex with men in Vigo-Spain.
abstract: BACKGROUND
  Men who have sex with men (MSM) infected with human immunodeficiency virus (HIV) have the highest risk of developing anal cancer (AC). The objective of this study was to describe our screening implementation program in this population, and report the prevalence of human papillomavirus (HPV) anal infection, and cytological and histological findings in a Spanish medium-size community (Vigo, Spain).
  
  
  METHODS
  Prospective cohort analysis of 240 HIV-infected MSM. Cellular anal sample and high risk HPV (HR-HPV)-tests were performed to study cytological changes and HPV genotyping. High resolution anoscopy (HRA) was performed in 209 patients. Results were analyzed with respect to epidemiological, clinical and analytical factors.
  
  
  RESULTS
  Of 209 patients selected for HRA, the prevalence of HR-HPV anal infection, cytological and histological alterations was 85.6%, 47.5%, and 39.8%, respectively. Sensitivity and specificity for ≥ ASCUS (atypia of squamous cells of undetermined significance) cytology in relation to histological alterations were 61% and 85%, (OR: 8.7; IC 95%: 4.4-17.2), respectively. Observed concordance between high-grade squamous intraepithelial lesion (HSIL) cytology and HSIL anal intraepithelial neoplasia types 2 and 3 (AIN-2/3) histology was 64% (OR: 11.4; IC 95%: 3.6-36.7). One patient with HSIL cytology presented a prevalent anal squamous carcinoma.
  
  
  CONCLUSIONS
  HRA was feasible with similar results to relevant groups. There was a high prevalence of anal HR-HPV infection, and cytological and histological alterations.
authors.affiliation: Cirugía general, Complejo Hospitalario Universitario de Vigo, España.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Iribarren Díaz
authors.affiliation: Medicina Interna, Complexo Hospitalario Universitario de Vigo, España.
authors.forename: Antonio
authors.initials: A
authors.lastname: Ocampo Hermida
authors.affiliation: Anatomía Patológica, Complexo Hospitalario Universitario de Vigo, España.
authors.forename: Joaquín
authors.initials: J
authors.lastname: González-Carreró Fojón
authors.affiliation: Medicina Interna, Complexo Hospitalario Universitario de Vigo, España.
authors.forename: Rebeca
authors.initials: R
authors.lastname: Longueira Suárez
authors.affiliation: Medicina Interna, Complexo Hospitalario Universitario de Vigo, España.
authors.forename: Alberto
authors.initials: A
authors.lastname: Rivera Gallego
authors.affiliation: Cirugía general, Complexo Hospitalario Universitario de Vigo, España.
authors.forename: Enrique
authors.initials: E
authors.lastname: Casal Núñez
authors.affiliation: Biólogo, departamento calidad., Freshcut S.L, España.
authors.forename: Antón
authors.initials: A
authors.lastname: Ocampo Álvarez
authors.affiliation: Department of Medicine, Owen Clinic. University of California at San Diego, Estados Unidos.
authors.forename: Edward R
authors.initials: ER
authors.lastname: Cachay
mesh_terms: D000328:Adult; D001005:Anus Neoplasms / Q000175:diagnosis* / Q000453:epidemiology; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D015658:HIV Infections / Q000150:complications* / Q000453:epidemiology; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D030361:Papillomavirus Infections / Q000175:diagnosis* / Q000453:epidemiology; D011230:Precancerous Conditions / Q000175:diagnosis; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D012725:Sexual Behavior