Risk of Cervical Cancer Following Incident, Persistent and History-unknown HPV Detection

The goal of this register-based retrospective observational study is to understand the risk of cervical cancer following incident, persistent and history-unknown HPV detection by HPV genotype in healthy women participating in HPV-based cervical screening. The main questions it aims to answer are: 1. Whether an incident HPV detection with certain HPV genotypes has low risk of cervical cancer in 3 to 5 years thus does not need further clinical assessment before the next screening test? 2. How risky a persistent HPV detection is, and whether persistent detection of any high-risk HPV genotype warrant immediate clinical assessment? 3. How risky a HPV detection is, if no previous HPV test result is available? As being a register-based retrospective observational study, study subjects will not be asked to do any specific task for this study.