Presence of koilocytosis in low-grade smears of high-risk HPV-positive women is a negative predictor for cervical intraepithelial neoplasia grade 3 or more.

Objective: The Netherlands converted to high-risk (hr)HPV-based screening in 2017. An increase in referral of hrHPV-positive women with low risk for cervical intraepithelial neoplasia grade 3 or more (CIN3+) is anticipated and reduction of unjustified referrals will have priority. The relevance of koilocytosis in relation to the underlying risk of high-grade CIN in a primary HPV screening setting is unclear. The aim was to investigate whether the risk for CIN3+ differs between hrHPV-positive atypical squamous cells of undetermined significance (ASC-US)/low-grade squamous intraepithelial lesion (LSIL) with or without koilocytosis.
Methods: Retrospective cohort study, using data from the Dutch national pathology database (PALGA). The population was 1201 hrHPV-positive women with cytological diagnosis of ASC-US/LSIL. Reporting of koilocytosis was assessed as well as detection rates of CIN1 or less, CIN2 and CIN3+ for ASC-US/LSIL cytology stratified by presence or absence of koilocytosis. Crude and adjusted odds ratios were determined.
Results: Koilocytosis was present in 40.1% of ASC-US and 45.9% of LSIL cases. CIN3+ is significantly less often found when koilocytosis is present (7.8% for hrHPV-positive ASC-US with- vs 15.8% without koilocytosis). For hrHPV-positive LSIL this was 11.7% vs 20.2%. The crude and adjusted odds ratios for CIN3+ was 0.45 for hrHPV-positive ASC-US and 0.52 for hrHPV-positive LSIL.
Conclusions: The presence of koilocytosis is a negative predictor of CIN3+. The risk of hrHPV-positive ASC-US with koilocytosis is in the same range as hrHPV-positive/cytology negative cases and in a setting of primary hrHPV screening these cases could be followed conservatively by repeat cytology. The results should be confirmed by the first data from the Dutch HPV-based screening programme.
(© 2018 John Wiley & Sons Ltd.)