Evaluation of the Use of Methylation as a New Tool for the Diagnostics and Progression of Squamous Intraepithelial Lesions

Vaccination against human papillomavirus (HPV) significantly reduces the incidence of HPV-related lesions worldwide. Considering the increasingly young age of patients in gynecological offices and earlier sexual initiation and potential contact with the HPV virus, doctors need the tools to verify diagnoses. Currently, women plan to pursue motherhood later, so it is necessary to consider whether sexual treatment in the form of, among others, loop electrosurgical excision procedures (LEEPs) may increase the risk of premature birth or difficulty dilating the cervix during labour. For this reason, to avoid the overtreatment of low-grade squamous intraepithelial lesions (LSILs), methylation testing may be considered. In patients with histopathologically confirmed high-grade squamous intraepithelial lesions (HSILs) during biopsy and, ultimately, a lower diagnosis, i.e., LSIL or no signs of atypia, methylation was found to be a useful tool. We performed a Pap smear, HPV genotyping, a punch biopsy, LEEP-conization (if needed), and methylation tests on 108 women admitted to the District Public Hospital in Poland. Women with a negative methylation test result were significantly more likely to be ultimately diagnosed with LSIL (<i>p</i> = 0.013). This means that in 85.7% of the patients with HSIL, major cervical surgery could be avoided if the methylation test was negative. Methylation testing, as well as dual-staining and diagnostics detecting the mRNA transcripts of highly oncogenic types of HPV, might be used in the future in the diagnosis of pre-cancerous conditions, mainly of the cervix, and in HPV-dependent cervical cancer screening. The methylation test may also be used in the diagnosis and identification of lesions within the cervical canal, including those located deep within the frontal crypts, not visible even during a professional colposcopic evaluation of the cervix.