Prognostic Significance of the Detection of Human Papilloma Virus L1 Protein in Smears of Cervical Intraepithelial Neoplasia Grade 3 in Pregnant Women.

Background/aim: Cervical intraepithelial neoplasia (CIN) III/high-grade squamous lesions (HSIL) remains a significant challenge during pregnancy. Current data on the course of disease are contradictory, with cases of progression to cervical cancer (CC) during pregnancy being observed. Evidence suggests that the expression of L1 capsid protein is associated with a favorable prognosis in non-pregnant women. The aim of this study was to evaluate L1 expression in pregnant women with CIN III/HSIL.

Patients and methods: Between 2008 and 2021, the conventional PAP-smears from pregnant women were retrospectively analyzed for the expression of L1. Only women with histologically confirmed CIN III/HSIL during pregnancy were included.

Results: A total of 161 women were included in this study; among them, 32 women (19.9%) had regressive disease postpartum. The majority of women (n=123, 76.4%) had persistent disease. In six cases, invasive CC was histologically proven postpartum (3.7%). In 113 women (70.2%) the PAP-Smears were L1- and 29.2% (n=48) of women were L1+. The rates of regression for L1+ were higher than for L1-, 25% vs. 17.7%, respectively. Rates for persistence were similar, at 75% and 78%, respectively. All cases of progression to CC were L1 negative during pregnancy.

Conclusion: In pregnant women, the rates of regression were higher in L1+ CIN III/HSIL cases. All women who progressed to CC were L1-. Therefore, detecting L1 expression could serve as a valuable test to rule out progression to CC in pregnant women. This approach may provide reassurance to women, allowing them to continue their pregnancies with reduced fear and anxiety about CIN III/HSIL during pregnancy.