We explored the association of HPV16 DNA methylation with age, viral load, viral persistence, and risk of incident and prevalent high grade CIN (CIN2+) in serially collected specimens from the Guanacaste, Costa Rica cohort. 273 exfoliated cervical cell specimens (diagnostic and pre-diagnostic) were selected: 1) 92 with HPV16 DNA clearance (controls), 2) 72 with HPV16 DNA persistence (without CIN2+), and 3) 109 with CIN2+. DNA was extracted, bisulfite converted and methylation was quantified using pyrosequencing assays at 66 CpGs across the HPV genome. The Kruskal-Wallis test was used to determine significant differences among groups, and receiver operating characteristic curve analyses were used to evaluate how well methylation identified women with CIN2+. In diagnostic specimens, 88% of CpG sites had significantly higher methylation levels in CIN2+ after correction for multiple tests compared with controls. The highest AUC was 0.82 for CpG site 6457 in L1, and a diagnostic sensitivity of 91% corresponded to a specificity of 60% for CIN2+. Prospectively, 17% of CpG sites had significantly higher methylation in pre-diagnostic CIN2+ specimens (median time of 3 years before diagnosis) vs. controls. The strongest pre-diagnostic CpG site was 6367 in L1 with an AUC of 0.76. Age-stratified analyses suggested that women older than the median age of 28 years have an increased risk of precancer associated with high methylation. Higher methylation in CIN2+ cases was not explained by higher viral load. We conclude that elevated levels of HPV16 DNA methylation may be useful to predict concurrently diagnosed as well as future CIN2+.

High‐risk human papillomavirus (hrHPV) DNA tests have excellent sensitivity for detection of cervical intraepithelial neoplasia 2 or higher (CIN2+). A drawback of hrHPV screening, however, is modest specificity. Therefore, hrHPV‐positive women might need triage to reduce adverse events and costs associated with unnecessary colposcopy. We compared the performance of HPV16/18 genotyping with a predefined DNA methylation triage test (S5) based on target regions of the human gene EPB41L3, and viral late gene regions of HPV16, HPV18, HPV31 and HPV33. Assays were run using exfoliated cervical specimens from 710 women attending routine screening, of whom 38 were diagnosed with CIN2+ within a year after triage to colposcopy based on cytology and 341 were hrHPV positive. Sensitivity and specificity of the investigated triage methods were compared by McNemar's test. At the predefined cutoff, S5 showed better sensitivity than HPV16/18 genotyping (74% vs 54%, P = 0.04) in identifying CIN2+ in hrHPV‐positive women, and similar specificity (65% vs 71%, P = 0.07). When the S5 cutoff was altered to allow equal sensitivity to that of genotyping, a significantly higher specificity of 91% was reached (P < 0.0001). Thus, a DNA methylation test for the triage of hrHPV‐positive women on original screening specimens might be a valid approach with better performance than genotyping.

DNA methylation changes in human papillomavirus type 16 (HPV16) DNA are common and might be important for identifying women at increased risk of cervical cancer. Using recently published data from Costa Rica we developed a classification score to differentiate women with cervical intraepithelial neoplasia grade 2 or 3 (CIN2/3) from those with no evident high-grade lesions. Here, we aim to investigate the performance of the score using data from the UK. Exfoliated cervical cells at baseline and 6-months follow-up were analyzed in 84 women selected from a randomized clinical trial of women undergoing surveillance for low-grade cytology. Selection of women for the methylation study was based on detectable HPV16 in the baseline sample. Purified DNA was bisulfite converted, amplified and pyrosequenced at selected CpG sites in the viral genome (URR, E6, L1 and L2), with blinding of laboratory personnel to the clinical data. The primary measure was a predefined score combining the mean methylation in L1 and any methylation in L2. At the second follow-up visit, 73/84 (87%) women were HPV16 positive and of these 25 had a histopathological diagnosis of CIN2/3. The score was significantly associated with CIN2/3 (area under curve = 0.74, p = 0.002). For a cutoff with 92% sensitivity, colposcopy could have been avoided in 40% (95% CI 27–54%) of HPV16 positive women without CIN2/3; positive predictive value was 44% (32–58%) and negative predictive value was 90% (71–97%). We conclude that quantitative DNA methylation assays could help to improve triage among HPV16 positive women.

ObjectiveTesting for high risk human papillomavirus (HR-HPV) is increasing; however due to limitations in specificity there remains a need for better triage tests. Research efforts have focused recently on methylation of human genes which show promise as diagnostic classifiers.MethodsMethylation of 26 genes: APC, CADM1, CCND2, CDH13, CDKN2A, CTNNB1, DAPK1, DPYS, EDNRB, EPB41L3, ESR1, GSTP1, HIN1, JAM3, LMX1, MAL, MDR1, PAX1, PTGS2, RARB, RASSF1, SLIT2, SOX1, SPARC, TERT and TWIST1 was measured by pyrosequencing in cytology specimens from a pilot set of women with normal or cervical intraepithelial neoplasia grade 3 (CIN3) histology. Six genes were selected for testing in Predictors 1, a colposcopy referral study comprising 799 women. The three genes EPB41L3, DPYS and MAL were further tested in a second colposcopy referral study, Predictors 2, comprising 884 women.ResultsThe six genes selected from the pilot: EPB41L3, EDNRB, LMX1, DPYS, MAL and CADM1 showed significantly elevated methylation in CIN2 and CIN3 (CIN2/3) versus ≤CIN1 in Predictors 1 (p < 0.01). Highest methylation was observed in cancer tissues. EPB41L3 methylation was the best single classifier of CIN2/3 in both HR-HPV positive (p < 0.0001) and negative samples (p = 0.02). Logistic regression modeling showed that other genes did not add significantly to EPB41L3 and in Predictors 2, its classifier value was validated with AUC 0.69 (95% CI 0.65–0.73).ConclusionSeveral methylated genes show promise for detecting CIN2/3 of which EPB41L3 seems the best. Methylated human gene biomarkers used in combination may be clinically useful for triage of women with HR-HPV infections.

Testing for high-risk (hr) types of human papillomavirus (HPV) is highly sensitive as a screening test of high-grade cervical intraepithelial neoplastic (CIN2/3) disease, the precursor of cervical cancer. However, it has a relatively low specificity. Our objective was to develop a prediction rule with a higher specificity, using combinations of human and HPV DNA methylation. Exfoliated cervical specimens from colposcopy-referral cohorts in London were analyzed for DNA methylation levels by pyrosequencing in the L1 and L2 regions of HPV16, HPV18, HPV31 and human genes EPB41L3, DPYS and MAL. Samples from 1,493 hrHPV-positive women were assessed and of these 556 were found to have CIN2/3 at biopsy; 556 tested positive for HPV16 (323 CIN2/3), 201 for HPV18 (73 CIN2/3) and 202 for HPV31 (98 CIN2/3). The prediction rule included EPB41L3 and HPV and had area under curve 0.80 (95% CI 0.78–0.82). For 90% sensitivity, specificity was 36% (33–40) and positive predictive value (PPV) was 46% (43–48). By HPV type, 90% sensitivity corresponded to the following specificities and PPV, respectively: HPV16, 38% (32–45) and 67% (63–71); HPV18, 53% (45–62) and 52% (45–59); HPV31, 39% (31–49) and 58% (51–65); HPV16, 18 or 31, 44% (40–49) and 62% (59–65) and other hrHPV 17% (14–21) and 21% (18–24). We conclude that a methylation assay in hrHPV-positive women might improve PPV with minimal sensitivity loss.