The following is a summary of “Clinical course of cervical intraepithelial neoplasia grade 2: a population-based cohort study,” published in the December 2023 issue of Obstetrics and Gynecology by Lycke et al.
Cervical intraepithelial neoplasia grade 2 (CIN2) has traditionally been the threshold for surgical intervention, but due to substantial regression rates, many countries are shifting toward active surveillance.
Researchers conducted a retrospective study investigating the comprehensive description of regression and progression rates of CIN2 using nationwide healthcare registry data.
They characterized the rates of regression and progression of CIN2 in women aged 18 to 40 years undergoing active surveillance in Denmark (1998 to 2020). A nationwide population-based cohort study was conducted, excluding women with a history of CIN2 or worse or surgical excision. Cumulative incidence functions were used to estimate regression and progression rates at 6, 12, 18, and 24 months post-diagnosis. Modified Poisson regression was employed to estimate crude and adjusted relative risks of progression within 24 months, stratified by index cytology and age.
The results showed 11,056 women on active surveillance, 6,767 experienced regression, and 3,580 progressed within 24 months. The regression rates were 62.9% (95% CI, 61.9–63.8), and progression rates were 33.3% (95% CI, 32.4–34.2) at the 24-month follow-up. Most regression (90%) and progression (90%) events occurred within the first 12 months. Women with high-grade index cytology had a higher risk of progression than those with normal index cytology (adjusted relative risk, 1.58; 95% CI, 1.43–1.76), while no significant age-related differences in progression risk were observed (adjusted relative, 0.98; 95% CI, 0.88–1.10) between women aged 30-40 years and those aged 23-29 years.
They concluded that the high regression rates observed for CIN2 support the shift in clinical management towards active surveillance, particularly for women with low-grade or normal index cytology.