Oncogenic human papillomavirus is not helpful for cytology screening of the precursor lesions of anal cancers in Taiwanese men who are infected with human immunodeficiency virus

Homosexual men infected with human immunodeficiency virus (HIV) are at increased risk of developing anal cancer. The aim of this study was to assess the clinical sensitivity of anal cytology analysis and oncogenic human papillomavirus (HPV) detection for predicting histological anal intraepithelial neoplasia. Between March 2011 and December 2013, we enrolled 196 HIV-positive men in Taoyuan General Hospital, Taiwan. We analyzed the results of thin-preparation anal Pap smears, HPV genotyping, and histology of anoscopic biopsy samples. The mean age (+/- standard deviation) was 31.43 (+/- 8.74) years. The proportion (95 % confidence interval) with abnormal thin-preparation anal cytology was 36.2 % (29.8-43.2 %): 16.8 % (12.2-22.7 %) atypical squamous cells of undetermined significance, 14.8 % (10.5-20.4 %) low-grade squamous intraepithelial lesions, and 4.6 % (2.4-8.5 %) high-grade squamous intraepithelial lesions. At least one HPV genotype was detected in 90.8 % of subjects, and the mean number of HPV infection types was 4.41 (+/- 3.24).The frequency of histological high-grade anal intraepithelial lesions was 7.14 % (95 % confidence interval 4.3-11.6 %). Anal cytology yielding atypical squamous cells of undetermined significance or higher grades resulted in a sensitivity of 64.3 %, specificity of 65.9 %, positive predictive value of 12.7 %, and negative predictive value of 96 %. Using both oncogenic HPV and cytology did not provide better performance. Anal cytology yielding atypical squamous cells of undetermined significance or higher grades could detect two-thirds of high-grade anal intraepithelial neoplasias in HIV-infected men and should be promoted for anal cancer prevention.