Assessment of Anal Cancer Screening Tools in Detecting High-Grade Anal Squamous Intraepithelial Lesions in Women.

Abstract

The aim of the study was to evaluate the validity of anal cytology against high-resolution anoscopy in the detection of anal high-grade squamous intraepithelial lesions (HSILs) among women in a clinical setting in Puerto Rico, alone and in combination with high-risk human papillomavirus (HR-HPV) typing. A cross-sectional study was done among 128 eligible women who attended the Anal Neoplasia Clinic of the University of Puerto Rico Comprehensive Center between 2014 and 2019. Kappa (κ) coefficient, sensitivity, specificity, positive predictive value, and negative predictive value were calculated using high-resolution anoscopy with biopsy as the criterion standard test. Poisson regression was used to estimate the adjusted prevalence ratio of anal HR-HPV infection. Overall, 71.1% of women were HIV infected and 78.9% had anal HR-HPV infection. Squamous intraepithelial lesions were detected with anal cytology and histology in 70.3% and 81.3% of women, respectively. The κ statistic between the tests (cytology and histology) was 0.32 (p < .05). Measured against the results from histology, the sensitivity of anal cytology alone to detect HSIL was 85.4% (95% CI = 72.2%-93.9%), whereas specificity was 38.8% (95% CI = 28.1%-50.3%). Although the sensitivity of the 2 tests combined (anal cytology and HR-HPV typing) to detect histologically confirmed HSIL increased (100.0%, 95% CI = 92.6%-100.0%), the specificity decreased (16.3%, 95% CI = 9.0%-26.2%). Meanwhile, women with HSIL had a higher prevalence of anal HR-HPV infection than those with no SIL/LSIL (prevalence ratio = 6.23, 95% CI = 1.50-25.83). Anal cytology in combination with HR-HPV typing for the screening of anal intraepithelial neoplasia improved the detection of HSIL in women.