THE CHANGE IN PREVALENCE OF HIGH-RISK HPV GENOTYPES IN CERVICAL CANCER AND PRECANCER IN LATVIA FROM 2016 TO 2024.

Description

Introduction: Over a decade of active HPV screening and vaccination has changed the prevalence of high-risk HPVs (HR-HPV). HPV vaccination in Latvia started in 2010 with Cervarix, replaced by Gardasil9 in 2020. This retrospective study aimed to determine changes in the dominant hrHPV genotypes in cervical dysplasia (CD) and cancer (CC) in Latvia from 2016 to 2024.
Methods: FFPE cervical tissue samples from patients with CD and CC were retrieved from the hospital repository. DNA was isolated with QIAamp DNA FFPE advanced UNG kit (Qiagen). HPVs were genotyped using Anyplex™ II HPV HR Detection kit (Seegene).
Results: Samples from 128 patients were retrieved, none were HPV vaccinated (>12 years in 2010; Table 1). Most were HR-HPV(+) – all CC and 90.2% (46/51) of CD samples. HPV16 was the most common, followed by HPV33 (Table 2). HPV56, HPV52, and HPV45 were found only in CC, and HPV31 and HPV66, in CD.Samples were grouped by year of collection: all and CC samples into 2016-2017, 2018-2019, 2020-2021, and 2022-2024, and CD samples into 2016-2018, 2019-2020, and 2021-2023. HPV16 tended to decrease (Fig. 1(F.1)). The decrease was significant in CD – there were less HPV16(+) in 2021-2023 than in 2016-2018 (F.1B). HPV18 decreased overall, in CC and in CD, while HPV33 and HPV45 increased, in case of HPV33, significantly (F.1). There were more HPV33(+) overall and in CC samples in 2020-2021 and 2022-2024 compared to 2018-2019 (F.1A, F1.C).
Conclusions: HPV16 is the most prevalent among HPV-nonvaccinated. HPV16/18, which have been targeted by vaccines the longest, are decreasing in prevalence, while others are on the rise. HPV16/18 decrease might signify a herd effect and have opened a niche for other hrHPVs. Thus, the introduction of multivalent vaccines (including such HrHPVs as HPV33 and 45) seems crucial in protecting the next generations. Acknowledgments: Latvian Science Council grant LZP-2021/1-0484.

Period	14 Nov 2024 → 15 Nov 2024
Event title	International Papillomavirus Conference 2024
Event type	Conference
Location	Edinburgh, United KingdomShow on map
Degree of Recognition	International