Lovisa Bergengren

Molecular triage on HPV-positive samples in a cervical screening setting

Objective To improve human papilloma virus (HPV) screening, more effective triage methods for HPV-positive samples need development and validation. Cytology, the most common triage method today, is subjective and can only be applied to professionally collected samples. Methylation status has been shown to be informative, as genes are highly methylated in HPV-induced cervical dysplasia and cancer. This study aimed to assess whether triaging HPV-positive samples using molecular methods, such as methylation and genotyping for high-risk HPV types, could be as effective as cytology in cervical screening. Methods A retrospective biobank study was conducted on HPV-positive samples collected in 2017–2018, analyzing FAM19A4/MiR-124-2 hypermethylation and HPV genotyping for types 16, 18, 31, 33, 45, 52, and/or 59, comparing these results to cytology triage for detecting histologically confirmed high-grade squamous intraepithelial lesions (HSIL) and cancer. Results Results from 1915 positive screening samples were analyzed, including 1052 follow-up biopsies with 402 HSIL or cancer cases. Genotyping showed slightly higher sensitivity than cytology but lower specificity, while methylation had higher specificity but much lower sensitivity. Cytology’s positive predictive value (PPV) was 36%, with lower PPVs for the molecular methods. Combining molecular methods increased the PPV but significantly reduced sensitivity. Conclusions Based on these findings with molecular methods reducing sensitivity, we do not recommend adopting the molecular triage methods evaluated in this study in the Swedish setting. The trade-off between sensitivity and specificity does not support a change from the current cytology-based triage approach.

Prevalence of HPV and pathological changes among women 70 years of age, 10 years after exclusion from the Swedish cervical cancer screening program

Abstract Purpose Örebro County introduced an updated screening program 2016 with primary HPV test for women over 30 years and prolonged screening, increasing the cut-off age from 56–60 to 64–70. The aim of this study was to investigate the prevalence of HPV genotypes and their correlation to histological changes in women, 10 years after exclusion from the screening program, due to an eventual implementation of a catch-up program including all women aged 60–70. Methods All women in Örebro County, born 1,946 (n = 1,968), were invited to a liquid-based cell sample with primary HPV screening. Samples were analyzed for hrHPV mRNA and positive samples were genotyped. hrHPV positive women were offered to do a conization. Results Out of 809 participants, 31 (3.8%) were hrHPV positive, of these 22 did a conization. Histologically, 5/22 (23%) had LSIL and 5/22 (23%) had HSIL. Normal histology was found in 12/22 (55%). The most prevalent genotypes were HPV 16, 33, 52, 56, and 68. Of the women with HSIL, one case of cervical cancer was confirmed in a recone biopsy after 4 months. Conclusion The study showed considerable prevalence of hrHPV and histologically confirmed LSIL/HSIL. These data led to catch-up screening for women between 60 and 70 years when overlapping two screening strategies.

Full genotyping and FAM19A4/miR124-2 methylation analysis in high-risk human papillomavirus–positive samples from women over 30 years participating in cervical cancer screening in Örebro, Sweden

Currently, cervical cancer prevention is undergoing comprehensive development regarding human papillomavirus (HPV) vaccination and cervical cancer screening. In Sweden and many other countries, high coverage vaccinated cohorts are entering screening within the next few years. This entails demands for baseline HPV genotype data across the screening age range for surveillance and a basis for screening program adjustment. In 2016, Örebro County, Sweden, changed to primary HPV screening using HPV mRNA testing followed by cytology triage. An alternative triage method to cytology could allow for a fully molecular screening algorithm and be implemented in a screening program where self-sampling is included. Hypermethylation analysis of the human genes FAM19A4/miR124-2 has been suggested as a promising triage method. HPV mRNA-positive screening samples (n = 529) were included and subjected to genotyping targeting a broad range of both low-risk and high-risk genotypes in addition to hypermethylation analysis of the two human genes FAM19A4/miR124-2. Data were connected to cytological and histological status and age. The most commonly detected genotypes were HPV31, 16, and 52. In addition, HPV18 was one of the most common genotypes in high-grade squamous intraepithelial lesions (HSILs) samples. In relation to available vaccines, 26% of the women with histological HSIL or cancer (≥HSIL) tested positive for only hrHPV included in the quadrivalent vaccine and 77% of the genotypes in the nonavalent vaccine. According to these figures, a relatively large proportion of the HSILs will probably remain, even after age cohorts vaccinated with the quadrivalent vaccine enter the screening program. Hypermethylation positivity was associated with increasing age, but no HPV-related independently predictive factors were found. Accordingly, age needs to be considered in development of future screening algorithms including triage with hypermethylation methodology.