PRINCess: The Prediction of Regression in CIN2 - A prospective study of young women under the age of 25 with biopsy proven CIN2 undergoing conservative management with assessment of regression, stable disease and progression.

Background: Women with cervical intraepithelial neoplasia grade 2 (CIN2) and grade 3 (CIN3) have a risk of developing cervical cancer and treatment by removing the affected tissue is usually recommended. However, treatment may increase the risk of early labour and delivery in future pregnancies. Studies indicate that CIN2 changes can spontaneously resolve without treatment in some young women. Thus, rather than treatment, close examination of the cervix every 6 months for up to 2 years is often recommended for young women with CIN2. Aims: Document for women <25 years with CIN2, safety of observational management, proportion of cell changes resolving without treatment, and factors which predict whether cell changes will resolve. Results: For the 508 women who completed the study, abnormalities resolved to low grade or normal for 351 (69%) and treatment was avoided, while 157 (31%) had a persistent high grade abnormality which was treated. No women progressed to cancer. Factors which increased the chance that the CIN2 would resolve were (1) not being infected with HPV types 16 or 18, (2) having a small area of abnormal cells (<0.5 cm), (3) abnormal cells appearing ‘low grade’ to a clinician, (4) being a non-smoker, and (5) a low grade smear. Conclusion: CIN2 abnormalities resolved without treatment in the majority of young women. Observational management of CIN2 in young women is safe and avoids the risks of over-treatment.