SHIFT IN HIGH RISK HPV GENOTYPES IN CERVICAL LESIONS AND CANCER IN LATVIA

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, exchanged for 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 (over 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. HPV56, HPV52, and HPV45 were found only in CC, and HPV31 and HPV66 - in CD. Samples were grouped: 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. The decrease was significant in CD – there were less HPV16(+) in 2021-2023 than in 2016-2018. HPV18 decreased overall, in CC and in CD, while HPV33 and HPV45 increased, in case of HPV33, significantly. There were more HPV33(+) overall and in CC samples in 2020-2021 and 2022-2024 than in 2018-2019.
Conclusions:
HPV16 is the most prevalent in the 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 seems pivotal in protecting the next generations.
Acknowledgments: Latvian Science Council grant LZP-2021/1-0484.

Period	22 Nov 2024
Event title	Viral infections and cancer, openings for vaccines and cure: Viruses and cancer
Event type	Conference
Location	Riga, LatviaShow on map
Degree of Recognition	International