Related Experiment Video
Updated: Aug 5, 2025

Tubal Cytology of the Fallopian Tube as a Promising Tool for Ovarian Cancer Early Detection
Published on: July 25, 2017
May Women with a Negative Co-Test at First Follow-Up Visit Return to 3-Year Screening after Treatment for Cervical
Finn Egil Skjeldestad1, Sveinung Wergeland Sørbye2
1Research Group Epidemiology of Chronic Diseases, Department of Community Medicine, UiT The Arctic University of Norway, 9037 Tromsø, Norway.
Background:
The Norwegian Cervical Cancer Screening Programme recommends that women treated for cervical intraepithelial neoplasia (CIN) only be returned to 3-year screening after receiving two consecutive negative co-tests, 6 months apart. Here we evaluate adherence to these guidelines and assessed the residual disease, using CIN3+ as the outcome.
Methods:
This cross-sectional study comprised 1397 women, treated for CIN between 2014 and 2017, who had their cytology, HPV, and histology samples analyzed by a single university department of pathology. Women who had their first and second follow-up at 4-8 and 9-18 months after treatment were considered adherent to the guidelines. The follow-up ended on 31 December 2021. We used survival analysis to assess the residual and recurrent CIN3 or worse among women with one and two negative co-tests, respectively.
Results:
71.8% (1003/1397) of women attended the first follow-up 4-8 months after treatment, and 38.3% were considered adherent at the second follow-up. Nearly 30% of the women had incomplete follow-up at the study end. None of the 808 women who returned to 3-year screening after two negative co-tests were diagnosed with CIN3+, whereas two such cases were diagnosed among the 887 women who had normal cytology/ASCUS/LSIL and a negative HPV test at first follow-up (5-year risk of CIN3+: 0.24, 95%, CI: 0.00-0.57 per 100 woman-years).
Conclusions:
The high proportion of women with incomplete follow-up at the end of the study period requires action. The risk of CIN3+ among women with normal cytology/ASCUS/LSIL and a negative HPV test at first follow-up is indicative of a return to 3-year screening.

