Expectancy as alternative to treatment for cervical intraepithelial neoplasia grade 2 in women aged 25 – 30 years: ExCIN2, a prospective clinical multicentre cohort study

Objective: To evaluate the natural course, over two years, of untreated cervical intraepithelial neoplasia grade 2 (CIN2) in women aged 25-30 years and the association with human papillomavirus 16 (HPV16). Design Prospective longitudinal multicentre clinical study. Setting Five colposcopy clinics, managing referrals after abnormal cervical screening in Region Västra Götaland (VGR), Sweden, February 2017-June 2021. Population of sample Per protocol: 127 women, aged 25-30 years, with histologically verified CIN2. Methods Surveillance with colposcopy, cytology, HPV testing and at least two cervical biopsies every six months, until progression or regression. Main outcome measures Respective rates of regression, persistence and progression of CIN2, in cases with HPV16 and without HPV16 at 6, 12, 18 and 24 months. Results Partial or total regression during the two-year period was found in 72% (Confidence interval 63-79). In patients with HPV16 the regression rate was 51% (36-66) and the progression rate 47% (32-62). In the HPV-non16 group 83% (73-90) regressed and 16% (9-26) progressed. Most of the regression and progression in both groups occurred within 15 months. Conclusions The regression rate of CIN2 is high and HPV16 is a strong determinant in the natural course. Patients aged 25 – 30 without HPV16 should generally be recommended active surveillance for one year. With HPV16 treatment should be considered. Funding The Healthcare Board, Region Västra Götaland, Sweden Keywords CIN2, natural course, regression, HPV 16