Low methylation marker levels among human papillomavirus-vaccinated women with cervical high-grade squamous intraepithelial lesions

Cervical cancer screening programs, including triage tests, need redesigning as human papillomavirus (HPV)-vaccinated women are entering the programs. Methylation markers offer a potential solution to reduce false-positive rates by identifying clinically relevant cervical lesions with progressive potential. In a nested case-control study, 9242 women who received the three-dose HPV16/18-vaccine at ages 12-15 or 18 in a community-randomized trial were included. Subsequently, they were re-randomized for either frequent or infrequent cervical cancer screening trials. Over a 15-year post-vaccination follow-up until 2022, 17 high-grade squamous intraepithelial lesion (HSIL) and 15 low-grade (LSIL) cases were identified at the 25-year screening round, alongside 371 age and community-matched HPV16/18-vaccinated controls. Methylation analyses were performed on cervical samples collected at age 25, preceding histologically confirmed LSIL or HSIL diagnoses. DNA methylation of viral (HPV16/18/31/33) and host-cell genes (EPB41L3, FAM19A4, and miR124-2) was measured, along with HPV-genotyping. No HPV16/18 HSIL cases were observed. The predominant HPV-genotypes were HPV52 (29.4%), HPV59/HPV51/HPV58 (each 23.5%), and HPV33 (17.7%). Methylation levels were generally low, with no significant differences in mean methylation levels of viral or host-cell genes between the LSIL/HSIL and controls. However, a significant difference in methylation levels was found between HSIL cases and controls when considering a combination of viral genes and EPB41L3 (p value = .0001). HPV-vaccinated women with HSIL had HPV infections with uncommon HPV types that very rarely cause cancer and displayed low methylation levels. Further investigation is warranted to understand the likely regressive nature of HSIL among HPV-vaccinated women and its implications for management. Cervical cancer screening programs, including triage tests, need to be redesigned as human papillomavirus (HPV)-vaccinated women now enter the programs. In this nested case-control study, HPV-vaccinated women with cervical high-grade squamous intraepithelial lesions had infections with HPV genotypes that very rarely cause cancer in this age group. Moreover, they displayed low methylation levels similar with those in HPV-vaccinated women with low-grade squamous intraepithelial lesions and HPV-vaccinated controls. The low methylation levels and potential for lesion regression suggest that HPV-vaccinated women would benefit from active surveillance of their high-grade squamous intraepithelial lesions rather than immediate treatment. image