Triage of cervical cytological diagnoses of atypical squamous cells by DNA methylation of paired boxed gene 1 (PAX1)

Detection of cervical high‐grade squamous intraepithelial lesions (HSIL) in patients with equivocal cytological abnormalities, such as atypical squamous cells (ASC) of undetermined significance (ASCUS) or inability to exclude high‐grade squamous intraepithelial lesions (ASC‐H) is still a challenge. This study tested the efficacy of PAX1 methylation analysis in the triage of cervical ASCUS and ASC‐H and compared its performance with Hybrid Capture 2 (HC2) HPV test. A hospital‐based case–control study was conducted. Cervical scrapings from patients with ASCUS or ASC‐H were used for the quantitative methylation analysis of PAX1 methylation by MethyLight and HPV testing by HC2. Patients with ASC‐H or ASCUS with repeated abnormal smears underwent colposcopic biopsy and subsequent therapies. Diagnoses were made by histopathology at a follow‐up of 2 years. The efficacies of detecting high‐grade lesions were compared. Fifty‐eight cervical scrapings with cytological diagnosis of ASCUS (n = 41) and ASC‐H (n = 17) were analyzed. One of the 41 (2.4%) ASCUS patients and seven of 17 (41.2%) ASC‐H patients were confirmed to have HSIL. After dichotomy of the PMR, PAX1 methylation rates were significantly higher in ASC developing HSIL compared with those developing reactive atypia (87.5% vs. 12.5%, P < 0.001). Testing PAX1 methylation in cervical swabs of patients with ASC confers better sensitivity (87.5% vs. 62.5%) and specificity (98.0% vs. 86.0%) than HC2 HPV testing. We show for the first time that PAX1 hypermethylation analysis may be a better choice than HC2 in the triage of ASCUS and ASC‐H. Diagn. Cytopathol. 2013. © 2011 Wiley Periodicals, Inc.