DNA-Methylation for Risk-Stratification of Women Without a Fully Visible Transformation Zone at Colposcopy: A Cross-Sectional Study

Abstract

Objective: To evaluate the performance of DNA methylation markers for the detection of cervical precancer among screening-positive older women without a fully visible transformation zone at colposcopy (TZ3). Design: Cross-sectional study. Setting: Colposcopy clinics, Central Denmark Region, 2019–2021. Population: Women ≥ 45 years with a TZ3 at colposcopy. Methods: Participants referred for colposcopy due to an abnormal cervical screening test underwent cervical cytology sampling, biopsies and a large loop excision of the transformation zone (LLETZ). Cytology samples were analysed for DNA methylation markers: FAM19A4/miR124-2, ARID3C/ARL5C and METloc001/METloc002 according to the manufacturer's instructions. LLETZ histology was the reference standard. Main Outcome Measures: Sensitivity and specificity of the methylation markers for cervical intraepithelial grade 2 or worse (CIN2+) and cervical intraepithelial grade 3 or worse (CIN3+). Results: Among 89 women (median age: 67.9 years), 31 (34.8%) had CIN2+ and 16 (18.0%) had CIN3+ detected. Sensitivity for CIN2+ was similar across markers, ranging from 74.2% (95% CI: 55.4–88.1) to 77.4% (95% CI: 58.9–90.4), while specificity was lower for FAM19A4/miR124-2 (39.7%; 95% CI: 27.0–53.4) compared to ARID3C/ARL5C (65.5%; 95% CI: 51.9–77.5) and METloc001/METloc002 (82.8%; 95% CI: 70.6–91.4). Sensitivity for CIN3+ was slightly lower for FAM19A4/miR124-2 (75.0%; 95% CI: 47.6–92.7) compared to ARID3C/ARL3C (87.5%; 95% CI: 61.7–98.4) and METloc001/METloc002 (93.8%; 95% CI: 69.8–99.8). Similarly, specificity was lowest for FAM19A4/miR124-2 (35.6%; 95% CI: 24.7–47.7), higher for ARID3C/ARL5C (60.3%; 95% CI: 48.1–71.5) and highest for METloc001/METloc002 (93.8%; 95% CI: 63.9–84.7). Conclusions: Methylation markers, particularly METloc001/METloc002, may be useful for risk-based management of women with a TZ3 at colposcopy. Trial Registration: ClinicalTrials.gov identifier: NCT04298957 (https://www.clinicaltrials.gov/ct2/show/NCT04298957?term=NCT04298957&draw=2&rank=1).