76 Chapter 3 SINGLE MARKER CLASSIFIERS The methylation level distributions of ASCL1, LHX8, ST6GALNAC5, GHSR, SST and ZIC1 in hrHPV-positive cervical screening samples across histological subgroups are shown in Figure 3.2, displaying an increase with the severity of the underlying cervical disease (all p values < 3.8×10-10). All markers demonstrated a significant difference between methylation levels in CIN3 and subgroups no CIN (i.e., women with no histology or normal histology), CIN1 and CIN2 (all p values < 0.0001). The performance for CIN3+ was evaluated by ROC curves (Figure 3.3A) and quantified by AUCs ranging from 0.720 to 0.844. Two markers had AUC above 0.800, with highest AUC achieved by ASCL1 (AUC = 0.844), followed by LHX8 (AUC = 0.830). VALIDATION OF THE PREDEFINED BI-MARKER PANEL ASCL1/LHX8 The bi-marker panel ASCL1/LHX8 was found most discriminative for CIN3 and cancer among hrHPV-positive women in our earlier study 10. The performance of this predefined panel for CIN3+ is depicted in Figure 3.3B, with inclusion of the point estimates for cytology and HPV16/18 genotyping. The bi-marker panel achieved an AUC of 0.853 for CIN3+. At the predefined threshold 10, the panel yielded a CIN3+ sensitivity of 76.9% (95% CI 68.385.6%) and specificity of 74.5% (95% CI 71.1-77.9%; Table 3.1). All cervical carcinomas (n = 3) were classified as methylation positive. Cytology with threshold ASC-US had a CIN3+ sensitivity of 89.0% (95% CI 82.6-95.4%) and specificity 62.3% (95% CI 58.5-66.1%), and HPV16/18 genotyping a CIN3+ sensitivity 75.3% (95% CI 65.9-84.7%) and specificity of 65.0% (95% CI 60.9-69.1%). Combinations of HPV16/18 genotyping with cytology or methylation resulted in a CIN3+ sensitivity of 95.2% (95% CI 90.6-99.8%) and 86.7% (95% CI 79.5-94.0%), and a specificity of 43.7% (95% CI 39.7-47.8%) and 53.3% (95% CI 49.257.4%), respectively. The clinical performance for CIN2+ is shown in Table 3.1. When methylation data were stratified by cytology, the sensitivity for CIN3+ was 86.4% (95% CI 77.7-95.2%) and specificity was 52.4% (95% CI 37.3-67.5%; Table 3.2) among hrHPV-positive women with high-grade cytology. For hrHPV-positive women with lowgrade cytology, CIN3+ sensitivity was 63.6% (95% CI 43.5-83.7%) and specificity was 75.1% (95% CI 69.0-81.2%). For hrHPV-positive women with normal cytology, CIN3+ sensitivity was 50.0% (95% CI 19.0-81.0%) and specificity was 76.6% (95% CI 72.4-80.8%). Methylation demonstrated a particularly good discriminatory power among hrHPVpositive women with low-grade cytology (RR CIN3+ 4.32; 95% CI 1.91-9.78, p value < 0.0001). HPV16/18 genotyping had a RR for CIN3+ of 2.53 (95% CI 1.14-5.62, p value = 0.0188) in this subgroup (Table 3.2). Data on the combinations of HPV16/18 genotyping
RkJQdWJsaXNoZXIy MjY0ODMw