Evaluation of the hybrid capture 2 assay for detecting anal high-grade dysplasia

Abstract

Hybrid Capture 2 (HC2) Human Papillomavirus (HPV) DNA Test® is FDA approved and is a proven aid in detecting HPV infections of the cervix and as an aid in diagnosing, with cytology, cervical disease. A prospective feasibility study was conducted to determine if HC2 testing has utility when screening for high-grade anal dysplasia (AIN2+). We enrolled 298 patients (45% HIV+) who had AIN2+ screening with cytology, histology and HC2 testing for two specimens: a swab into liquid-based cytology medium and either a swab or a brush collection in specimen transport medium (STM). High-resolution anoscopy was performed on all patients with biopsy of AIN2+ suspicious lesions. Cytology was benign (42%), atypical squamous cells of undetermined significance (30%), low-grade squamous intraepithelial lesion (18%), high-grade squamous intraepithelial lesion (1%), ASCUS possibly high-grade dysplasia (1.7%) and nondiagnostic (7%) and 36% had AIN2+ histology. Sensitivity and specificity for predicting AIN2+ histology for any abnormal cytology were 77 and 52%, whereas HC2 sensitivity and specificity were 91 and 40% (p = 0.005 for sensitivity), respectively. There was no significant difference in HC2 sensitivity or specificity between brush and swab or STM and residual cells from cytology. AIN2+ was found in 20% of patients with benign cytology. Only nine AIN2+ specimens were HC2-. This prospective study indicates that HC2 may be useful when screening for anal dysplasia; however, a larger study is recommended.