PLoS ONE (Jan 2016)

Cytological Anal Squamous Intraepithelial Lesions Associated with Anal High-Risk Human Papillomavirus Infections among Men Who Have Sex with Men in Northern Thailand.

  • Darin Ruanpeng,
  • Suwat Chariyalertsak,
  • Quanhathai Kaewpoowat,
  • Taweewat Supindham,
  • Jongkolnee Settakorn,
  • Kornkanok Sukpan,
  • Utaiwan Utaipat,
  • Toshiyuki Miura,
  • Natthapol Kosashunhanan,
  • Pongpun Saokhieo,
  • Radchanok Songsupa,
  • Antika Wongthanee

DOI
https://doi.org/10.1371/journal.pone.0156280
Journal volume & issue
Vol. 11, no. 5
p. e0156280

Abstract

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BACKGROUND:Anal cancer, one of human papillomavirus (HPV) related malignancies, has increased in recent decades, particularly among men who have sex with men (MSM) and HIV-infected (HIV+) persons. We aimed to explore the prevalence of anal squamous intraepithelial lesions (ASIL) using Papanicolau (Pap) screening among MSM in northern Thailand and its associated factors. METHODS:Two hundreds MSM aged ≥18 years reporting receptive anal intercourse in the prior 6 months were recruited from July 2012 through January 2013. Medical history and behavioral data were collected by staff interview and computer-assisted self interview. Anal Pap smear, HPV genotyping, and HIV testing were performed. Two pathologists blinded to HPV and HIV status reported cytologic results by Bethesda classification. RESULTS:Mean age was 27.2 years (range 18-54). Overall, 86 (43.0%) had ASIL: 28 (14.2%) with atypical cells of undetermined significance (ASCUS), 1 (0.5%) with atypical squamous cells-cannot exclude high-grade squamous intraepithelial lesion (ASC-H), 56 (28.4%) with low-grade squamous intraepithelial lesion (LSIL), and 1 (0.5%) with high-grade squamous intraepithelial lesion (HSIL). ASIL was associated by univariate analysis (p ≤0.05) with older age, gender identity other than bisexual (i.e., gay men and transgender women), rectal douching, anal symptoms, genital warts, HIV positivity, and high-risk-HPV infection. However, on multiple logistic regression ASIL was associated only with high-risk HPV type (p = 0.002) and HIV infection (p = 0.01). CONCLUSIONS:ASIL is quite common in high-risk MSM in northern Thailand and is associated with high-risk HPV types and HIV infection. Routine anal Pap screening should be considered, given the high frequency of ASIL, particularly in the HIV+. High resolution anoscopy (HRA), not done here, should be to confirm PAP smears whose sensitivity and specificity are quite variable. Timely HPV vaccination should be considered for this population.