Cervical Intraepithelial Neoplasia 3 (Cervical Intraepithelial Neoplasia 3/High-Grade Squamous Intraepithelial Lesion) in Human Papillomavirus-Vaccinated Women-Results From a Tertiary Referral Center.

OBJECTIVE: High-grade cervical intraepithelial neoplasia (CIN 3) still develops in some vaccinated women despite established effectiveness of prophylactic human papillomavirus (HPV) vaccination. The purpose of this study was to define characteristics of women with CIN 3 after HPV vaccination referred to a gynecological dysplasia unit. MATERIALS AND METHODS: Retrospective analysis of HPV-vaccinated women with CIN 3 in a single German center. Between July 2018 and September 2020, 791 women were referred to our university hospital-based dysplasia unit for colposcopic evaluation of abnormal cytological findings. Human papillomavirus vaccination status was retrieved. Human papillomavirus typing was performed in lesional biopsies and cervical swabs. RESULTS: Nine women were identified who had previously been vaccinated with the quadrivalent HPV vaccine (Q-HPV) and were diagnosed with histologically confirmed CIN 3/high-grade squamous intraepithelial lesion. The Q-HPV had been administered between 12 and 28 years of age and 1-13 years before CIN 3 diagnosis. Nine different high-risk (HR)-HPV types were found in the CIN 3 biopsies, 6 monoinfections (twice HPV 16, once HPV 18, HPV 31, HPV 52, HPV 58, respectively) and 3 dual infections (HPV 33 + 52, HPV 51 + 52, HPV 53 + 66). Seven of these 9 HR-HPV types are not covered by Q-HPV, but only 2 CIN 3 lesions carried HR-HPV types not included in the nonavalent HPV vaccine. CONCLUSIONS: It is important to implement vaccination recommendations and administer HPV vaccination as early as possible in HPV-naive individuals. Because not all HR-HPV types are covered by the available HPV vaccines, other types may still cause CIN 3/high-grade squamous intraepithelial lesion. This requires further screening after vaccination, especially in women who were previously vaccinated with the bivalent or the quadrivalent HPV vaccine.