Outcomes in women with biopsy-confirmed cervical intraepithelial neoplasia grade 1 or normal cervix and related cofactors: A 15-year population-based cohort study from China.

OBJECTIVE: To estimate long-term outcomes of biopsy-confirmed cervical intraepithelial neoplasia grade 1 (CIN1) or normal cervix and identify the cofactors during disease progression. METHODS: In 1999, a cervical cancer screening cohort in Shanxi, China, enrolled 1997 women aged 35-45. They were followed up at year 6, 11, and 15 after enrollment with high-risk human papillomavirus (hrHPV) DNA testing, liquid-based cytology, and visual inspection with acetic acid. Progression, persistence, and regression rates were calculated, stratified by baseline hrHPV and cytological status. Risk factors associated with hrHPV acquisition, persistence, and progression were examined. RESULTS: The cumulative rates of progression to CIN2+ among CIN1 over 6, 11, and 15 years were 7.5%, 21.4%, and 24.0%, respectively; the regression rates to normal cervix were 85.0%, 76.7%, and 72.9%, respectively. Over 6, 11, and 15 years, 0.7%, 2.9%, and 5.2% of normal cervix developed CIN2+, respectively, but over 90% remained normal after 15 years. CIN1 or normal cervix positive for hrHPV had significantly higher progression rates to CIN2+ than those without hrHPV. Similarly, the severity of cytological status was found to be associated with an increased risk of developing CIN2+. Women who had an earlier sexual debut were at a higher risk of acquiring new HPV infection and repeated HPV infections. CONCLUSIONS: Clinical follow-up strategies for women with CIN1 or normal cervix could be adjusted accordingly based on hrHPV/cytology status.