Trial23 - A Method Study on Cervical Screening in Women Offered HPV-vaccination as Girls

Cervical Intraepithelial Neoplasia (CIN)

Cervical screening, Human papillomavirus (HPV), Cytology, HPV-test, Cervical intraepithelial neoplasia (CIN)

In Denmark, the first birth cohorts of women offered HPV-vaccination as girls are entering the cervical screening program. These women are expected to be better protected against cervical cancer. It has not yet been decided how to screen these women. This method study will investigate a possible screening scheme that could provide a reduced burden of screening for HPV-vaccinated birth cohorts.

In Denmark, women aged 23-49 are offered cervical screening with liquid-based cytology (LBC) every 3rd year, and women aged 50-59 every 5th year. Women aged 60-64 are offered an exit HPV-DNA test. In 2008 vaccination against Human papilloma virus (HPV) was offered free of charge to girls aged 13-15. HPV-vaccination has been part of the child vaccination program for 12-year old girls since 2009. Women born in 1994 were offered HPV-vaccination at age 14, and approximately 80% are HPV-vaccinated. These women entered the screening program in 2017. HPV-testing is shown to provide a better protection against cervical cancer than cytology testing, and the 6-year protection against CIN3+ after a negative HPV-test has been observed to be higher than the 3-year protection after a negative cytology test (ref). The aim of the study is to evaluate if primary screening with HPV-testing and LBC triage every 6 years in women offered HPV-vaccination as girls would provide at least the same protection as the present screening, measured by cumulative number of cervical intraepithelial neoplasia (CIN). This screening scheme would allow HPV-negative women to benefit from a prolonged screening interval and thereby reduce the burden of screening for HPV-vaccinated birth cohorts. The study is deemed a method study by the ethical committee of the Capital region and informed consent is, therefore, not required. The study is approved by the Danish data protection agency. The study will be undertaken as a method study embedded in the existing cervical screening program in the study area: Region Zealand, Northern Denmark region, Central Denmark region and part of region of Southern Denmark. The study is planned to run over three screening rounds. We expect 12000 women to be screened in the baseline screening round. The study includes all women born in 1994 who live in the study area and participate in cervical screening. For a random half of these women, an HPV-DNA test is performed in addition to routine cervical cytology. The result of the HPV-test will not affect screening or follow-up, but is performed solely for purposes of the method study. CINtec p16 histology will be performed on all cervical biopsies in the study to ensure the quality of the diagnosis. When screening samples are received at the pathology labs the allocation (HPV+/- in addition to cytology) will appear automatically in the IT-system. The study will be conducted a non-inferiority study. If non-inferiority is declared, analysis for superiority will be conducted. Censoring will be performed in the event of death, emigration, end of study and at first cervical intraepithelial neoplasia grade 3 or above (CIN3+) or conization. Data on primary and secondary endpoints will be collected from National Health registers. The project is supported by funds from 'Det Frie forskningsråd', 'Helsefonden' and 'Johannes Clemmesens Forskningsfond'. Cobas HPV-DNA and CINtec p16 histology test-kits are sponsored by Roche. Both tests were in standard use in the pathology departments prior to the project. Results of the baseline screening round and final results from the study will be published in relevant peer-reviewed journals.

Denmark