Time trends in the clinical management of cervical intraepithelial neoplasia grade 2: A Danish register-based study

Active surveillance for cervical intraepithelial neoplasia grade 2 (CIN2) has been implemented recently in many countries, including the Nordic countries. In Denmark, the only eligibility criterion for active surveillance for CIN2 is that the woman should be of reproductive age. With this study, we aimed to evaluate clinical and socioeconomic characteristics in women with CIN2 managed by active surveillance or large loop excision of the transformation zone (LLETZ) and to evaluate temporal changes in the clinical management of CIN2.

We conducted a Danish nationwide study using data from healthcare registries. All female residents aged 18-40 years, diagnosed with incident CIN2 from January 1, 1998, to February 29, 2020, were included. We collected data on age, index cytology result, year of CIN2 diagnosis, region of residence, civil status, HPV vaccination status, and socioeconomic position indicators. The variables were tabulated overall and by management group (active surveillance vs. LLETZ). To evaluate time trends, we used joinpoint regression to calculate the annual percentage change (APC), including 95% confidence intervals (CI).

Of the 27 536 women with CIN2 included, 12 500 (45.4%) underwent active surveillance, and 15 036 (54.6%) underwent a LLETZ. Women undergoing active surveillance were younger, more often HPV-vaccinated, and more likely to have a normal/low-grade index cytology result than women undergoing LLETZ. Socioeconomic position indicators did not differ. Over time, the proportion of women undergoing active surveillance increased from 21.7% in 2004 to 73.6% in 2019 (APC 9.7, 95% CI 8.1-11.4). The proportion of women undergoing active surveillance aged <30 declined over time (APC -2.2, 95% CI -2.9 to -1.5). The proportion of women with normal/low-grade index cytology increased slightly to 51.6% in 2019 (APC 0.8, 95% CI 0.4-1.3).

The use of active surveillance for CIN2 has increased over the past two decades in Denmark. Observed differences in characteristics between women undergoing active surveillance vs LLETZ are likely related to indications for clinical management.