Estimating the direct effect of human papillomavirus vaccination on the lifetime risk of screen-detected cervical precancer

Detection of Multiple HPV Types in Liquid Biopsies of Cervical Neoplasia

BACKGROUND

More than 95% of cervical cancers and their precancerous lesions are caused by human papillomavirus (HPV). Cell-free (cf) HPV DNA detection in blood samples may serve as a monitoring tool for cervical cancer.

METHODS

In our methodological study, an HPV panel for simultaneous detection of 24 types using mass spectrometry-based analysis was developed for liquid biopsy approaches and tested on HPV positive cell lines, plasmid controls, and cervical high-grade squamous intraepithelial lesions (HSIL) in positive smear samples (n = 52). It was validated in cfDNA blood samples (n = 40) of cervical cancer patients.

RESULTS

The HPV panel showed proficient results in cell lines and viral plasmids with a limit of detection of 1 IU (international units)/µL for HPV16/18 and 10GE/µL for HPV11/31/33/39/45/51/52/58/59 and a specificity of 100% for the tested HPV types. In cervical smear samples, HPV DNA was detected with a sensitivity of 98.14%. The overall agreement between the new HPV panel and clinical records was 97.2% (κ = 0.84). In cervical cancer cfDNA, 26/40 (65.0%) tested positive for any HPV type, with most infections due to hrHPV (24/26). HPV positive samples were found in all FIGO stages, with the highest positivity ratio in FIGO III and IV. Even the lowest stage, FIGO I, had 12/23 (52.2%) patients with a positive HPV plasma status.

CONCLUSIONS

This proof-of-concept paper shows that the described assay produces reliable results for detecting HPV types in a multiplex mass spectrometry-based assay in cervical smear and cfDNA with high specificity and sensitivity in both cohorts. The assay shows potential for liquid biopsy-based applications in monitoring cervical cancer progression.

An Updated Analysis of the Impact of HPV Vaccination Based on Long-term Effectiveness in the Netherlands

INTRODUCTION

Vaccination against human papillomavirus (HPV) is considered the most effective strategy to protect women from cervical cancer. Three HPV vaccines are currently licensed in Europe and, although they are generally supported by favorable health economic outcomes, current models fall short in predicting vaccination benefits. Here, we aim to re-evaluate the health benefits of HPV vaccination, using updated long-term effectiveness data and emphasizing quality of life losses related to pre-cancer disease and treatment.

METHODS

We used a static Markov model that compared "only screening" (includes unvaccinated girls) and "vaccination" (assumes 100% vaccination coverage with the bivalent HPV vaccine). A lifetime cohort of 100,000 uninfected 12-year-old girls was included, in which the number of cases with cervical intraepithelial neoplasia grade 2 or higher/3 (CIN2+, CIN3), cervical cancer, and cervical cancer deaths per scenario were determined. Furthermore, the reduction in major excisional procedures, the preterm deliveries averted, and the related gain in quality-adjusted life years (QALYs) due to vaccination were estimated.

RESULTS

The bivalent vaccine showed larger reductions in CIN2+, CIN3, cervical cancer cases, cervical cancer deaths, and major excisional treatments, after including long-term efficacy and effectiveness data, compared to previous data. Moreover, we observed an increased amount of QALYs gained due to prevention of major excisional treatment and the negative side effects related to it.

CONCLUSIONS

Updated health economic models for HPV vaccination, using updated and long-term effectiveness data and including prevention of treatment-related side effects, demonstrate a substantial additional positive effect on vaccination outcomes. Indeed, extrapolation of the bivalent HPV vaccine's updated long-term effectiveness data against HPV-related cervical diseases shows that the positive effects of vaccination may be more substantial than previously estimated. There is a graphical abstract available for this article.

Maximizing the cost-effectiveness of cervical screening in the context of routine HPV vaccination by optimizing screening strategies with respect to vaccine uptake: a modeling analysis

BACKGROUND

Regarding primary and secondary cervical cancer prevention, the World Health Organization proposed the cervical cancer elimination strategy that requires countries to achieve 90% uptake of human papillomavirus (HPV) vaccines and 70% screening uptake. The optimal cervical screening strategy is likely different for unvaccinated and vaccinated cohorts upon national HPV immunization. However, health authorities typically only provide a one-size-fits-all recommendation for the general population. We aimed to evaluate the cost-effectiveness for determining the optimal screening strategies for vaccinated and unvaccinated cohorts.

METHODS

We considered the women population in Hong Kong which has a unique HPV infection and cervical cancer epidemiology compared to other regions in China and Asia. We used mathematical models which comprise a deterministic age-structured compartmental dynamic component and a stochastic individual-based cohort component to evaluate the cost-effectiveness of screening strategies for cervical screening. Following the recommendations in local guidelines in Hong Kong, we considered strategies that involved cytology, HPV testing, or co-testing as primary cervical screening. We also explored the impacts of adopting alternative de-intensified strategies for vaccinated cohorts. The 3-year cytology screening was used as the base comparator while no screening was also considered for vaccinated cohorts. Women's lifetime life years, quality-adjusted life years, and costs of screening and treatment were estimated from the societal perspective based on the year 2022 and were discounted by 3% annually. Incremental cost-effectiveness ratios (ICERs) were compared to a willingness to pay (WTP) threshold of one gross domestic product per capita (US $47,792). Probabilistic and one-way sensitivity analyses were conducted.

RESULTS

Among unvaccinated cohorts, the strategy that adds reflex HPV to triage mild cytology abnormality generated more life years saved than cytology-only screening and could be a cost-effective alternative. Among vaccinated cohorts, when vaccine uptake was 85% (based on the uptake in 2022), all guideline-based strategies (including the cytology-only screening) had ICERs above the WTP threshold when compared with no screening if the vaccine-induced protection duration was 20 years or longer. Under the same conditions, HPV testing with genotyping triage had ICERs (compared with no screening) below the WTP threshold if the routine screening interval was lengthened to 10 and 15 years or screening was initiated at ages 30 and 35 years.

CONCLUSIONS

HPV testing is a cost-effective alternative to cytology for vaccinated cohorts, and the associated optimal screening frequency depends on vaccine uptake. Health authorities should optimize screening recommendations by accounting for population vaccine uptake.

Cervical cancer screening guidelines and screening practices in 11 countries: A systematic literature review

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Screening guidelines and practices are heterogenous across 11 countries researched.

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Differences persist between screening guidelines and practices within countries.

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Only 6 of 11 countries here examined have national screening registries in place.

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Robust data infrastructure is essential to evaluate screening performance.

The World Health Organization (WHO) advocates population-based screening programs to reduce the global incidence of cervical cancer. However, screening guidelines and practice continually change to reflect scientific developments. Here we describe and compare cervical cancer screening guidelines and clinical practice in 11 countries across North America, Europe, and Asia-Pacific. We conducted a systematic literature review (SLR) complemented by a targeted literature review (TLR) to identify relevant peer-reviewed publications and policy documents, which include 120 publications, of which 86 were identified from the SLR and 34 from the TLR. Only six of 11 countries assessed have population-based screening programs in place. Considerable differences persist across countries’ screening guidelines, even among comparable systems. Moreover, methods of data collection are also heterogenous, and systematic data collection is often not established. As future changes in screening guidelines and clinical practice occur (e.g., when the first cohorts of women vaccinated against HPV reach screening age), systematic collection of screening data is essential to monitor and improve screening performance.

Human Papilloma Virus Vaccination

Human papilloma virus (HPV) is the most common sexually transmitted infection worldwide causing a variety of benign and malignant conditions. A significant portion of the global population is infected with HPV, with the virus attributed to causing up to 5% of cancers worldwide. Bivalent, quadrivalent, and nine-valent vaccinations exist to aid in the prevention of these diseases and have been proven to be effective at preventing both benign and malignant disease. While vaccination is readily accessible in more developed countries, barriers exist to worldwide distribution and acceptance of vaccination. Vaccination and screening of HPV infection when used in combination are proven and predicted to decrease HPV related pathology. Improvements in vaccination formulations, for treatment as well as prevention, are actively being sought from a variety of mechanisms. Despite these advancements, and the data supporting their efficacy, there has been substantial delay in obtaining adequate vaccination coverage. In reviewing these challenges and looking forward to new vaccine development—especially within the current pandemic—it is clear from the challenges of HPV we require methods to more effectively encourage vaccination, ways to dispel vaccination myths as they occur, and implement better processes for vaccine distribution globally.

Estimating the direct effect of human papillomavirus vaccination on the lifetime risk of screen-detected cervical precancer

Birth cohorts vaccinated against human papillomavirus (HPV) are now entering cervical cancer screening. Assessment of (pre)cancer (CIN3+) risk is needed to assess the residual screening need in vaccinated women. We estimated the lifetime (screen-detected) CIN3+ risk under five-yearly primary HPV screening between age 30 and 60, using HPV genotyping and histology data of 21,287 women participating in a screening trial with two HPV-based screening rounds, 5 years apart. The maximum follow-up after an HPV-positive test was 9 years. We re-estimated the CIN3+ risk after projecting direct vaccine efficacy for the bivalent and the nonavalent HPV vaccines, assuming life-long protection. The lifetime CIN3+ risk was 4.1% (95% confidence interval 3.5-4.9) and declined by 53.5% and 70.5% after bivalent vaccination without and with cross-protection, respectively, translating into a residual lifetime CIN3+ risk of 1.9% (1.4-2.4) and 1.2% (0.9-1.5). The CIN3+ risk declined by 88.5% after nonavalent vaccination, translating into a residual lifetime CIN3+ risk of 0.5% (0.2-0.7). The latter risk increased to 1.6% when vaccine protection only lasted until the first screening round at age 30. Among HPV-positive women with abnormal adjunct cytology, the nine-year CIN3+ risk was 16.9% (8.7-32.4) after nonavalent vaccination. In conclusion, HPV vaccination will lead to a strong decline in the lifetime CIN3+ risk and the remaining absolute CIN3+ risk will be very low. Primary HPV testing combined with adjunct cytology at five-year intervals still seems feasible even after nonavalent vaccination, although unlikely to be cost-effective. Our results support a de-intensification of screening programs in settings with high vaccination coverage.