Cervical cancer is associated with a persistent infection with high-risk HPV and develops through precancerous lesions (high-grade cervical intraepithelial neoplasia; CIN2/3). In CIN2/3 the normal viral life cycle is aborted and the viral oncogenes E6 and E7 are overexpressed in proliferating cells. This results in the induction of (epi)genetic changes that drive progression to cancer. With the introduction of primary hrHPV testing in cervical screening, these host cell changes provide promising markers for the management of hrHPV-positive women. These so-called triage markers ideally identify hrHPV-positive women with clinically relevant high-grade CIN lesions in need of treatment (‘’advanced CIN2/3’’).
We set out to discover and validate DNA methylation markers that can be used for triage of hrHPV-positive women.
Targeted and genome wide methylation discovery screens were performed on hrHPV-transformed cell lines and cervical tissue specimens. Candidate genes targeted by DNA methylation were validated by methylation-specific PCR (MSP) on cervical exfoliated cells.
We identified a series of candidate methylation target genes, of which the methylation levels showed a significant increase with severity of cervical disease (p<0.005). Analysis of HPV-positive cervical scrapes and self-collected cervico-vaginal specimens showed that these methylation markers enable the detection of all advanced CIN2/3 lesions and cervical cancers in both HPV-positive scrapes and self-collected specimens.
DNA methylation analysis provides an attractive triage tool for hrHPV-positive women, which is particularly useful for self-collected specimens. Triage by DNA methylation analysis specifically detects cervical lesions in need of treatment and can prevent overtreatment of non-progressive lesions.