The expected impact of HPV vaccination on the accuracy of cervical cancer screening: the need for a paradigm change

Epidemiology of HPV-associated cancers past, present and future: towards prevention and elimination

Cervical cancer is the first cancer deemed amenable to elimination through prevention, and thus lessons from the epidemiology and prevention of this cancer type can provide information on strategies to manage other cancers. Infection with the human papillomavirus (HPV) causes virtually all cervical cancers, and an important proportion of oropharyngeal, anal and genital cancers. Whereas 20th century prevention efforts were dominated by cytology-based screening, the present and future of HPV-associated cancer prevention relies mostly on HPV vaccination and molecular screening tests. In this Review, we provide an overview of the epidemiology of HPV-associated cancers, their disease burden, how past and contemporary preventive interventions have shaped their incidence and mortality, and the potential for elimination. We particularly focus on the cofactors that could have the greatest effect on prevention efforts, such as parity and human immunodeficiency virus infection, as well as on social determinants of health. Given that the incidence of and mortality from HPV-associated cancers remain strongly associated with the socioeconomic status of individuals and the human development index of countries, elimination efforts are unlikely to succeed unless prevention efforts focus on health equity, with a commitment to both primary and secondary prevention.

Predictable changes in the accuracy of human papillomavirus tests after vaccination: review with implications for performance monitoring in cervical screening

Vaccination against human papillomavirus (HPV) is changing the performance of cytology as a cervical screening test, but its effect on HPV testing is unclear. We review the effect of HPV16/18 vaccination on the epidemiology and the detection of HPV infections and high-grade cervical lesions (CIN2+) to evaluate the likely direction of changes in HPV test accuracy. The reduction in HPV16/18 infections and cross-protection against certain non-16/18 high-risk genotypes, most notably 31, 33, and/or 45, will likely increase the test's specificity but decrease its positive predictive value (PPV) for CIN2+. Post-vaccination viral unmasking of non-16/18 genotypes due to fewer HPV16 co-infections might reduce the specificity and the PPV for CIN2+. Post-vaccination clinical unmasking exposing a higher frequency of CIN2+ related to non-16/18 high-risk genotypes is likely to increase the specificity and the PPV of HPV tests. The effect of HPV16/18 vaccination on HPV test sensitivity is difficult to predict based on these changes alone. Programmes relying on HPV detection for primary screening should monitor the frequency of false-positive and false-negative tests in vaccinated (younger) vs. unvaccinated (older) cohorts, to assess the outcomes and performance of their service.

Impact of human papillomavirus age-related prevalence and vaccination levels on interpretation of cervical screening modalities: a modelling study

OBJECTIVE

Cervical screening is a life-saving intervention, which reduces the incidence of and mortality from cervical cancer in the population. Human papillomavirus (HPV) based screening modalities hold unique promise in improving screening accuracy. HPV prevalence varies markedly by age, as does resultant cervical intraepithelial neoplasia (CIN), with higher rates recorded in younger women. With the advent of effective vaccination for HPV drastically reducing prevalence of both HPV and CIN, it is critical to model how the accuracy of different screening approaches varies with age cohort and vaccination status. This work establishes a model for the age-specific prevalence of HPV factoring in vaccine coverage and predicts how the accuracy of common screening modalities is affected by age profile and vaccine uptake.

DESIGN

Modelling study of HPV infection rates by age, ascertained from European cohorts prior to the introduction of vaccination. Reductions in HPV due to vaccination were estimated from the bounds predicted from multiple modelling studies, yielding a model for age-varying HPV and CIN grades 2 and above (CIN2+) prevalence.

SETTING

Performance of both conventional liquid-based cytology (LBC) screening and HPV screening with LBC reflex (HPV reflex) was estimated under different simulated age cohorts and vaccination levels.

PARTICIPANTS

Simulated populations of varying age and vaccination status.

RESULTS

HPV-reflex modalities consistently result in much lower incidence of false positives than LBC testing, with an accuracy that improves even as HPV and CIN2+ rates decline.

CONCLUSIONS

HPV-reflex tests outperform LBC tests across all age profiles, resulting in greater test accuracy. This improvement is especially pronounced as HPV infection rates fall and suggests HPV-reflex modalities are robust to future changes in the epidemiology of HPV.

Enhancing Cervical Cancer Prevention in South African Women: Primary HPV mRNA Screening with Different Genotype Combinations

BACKGROUND

Cervical cancer prevention in regions with limited access to screening and HPV vaccination necessitates innovative approaches. This study explored the potential of a test-and-treat strategy using mRNA HPV tests to impact cervical cancer prevention in a high-prevalence HIV population.

METHODS

A cervical screening study was conducted at three South African hospitals involving 710 under-screened, non-pregnant women (25 to 65 years) without known cervical diseases. Cytology, HPV testing, colposcopy, and biopsies were performed concurrently. Histopathologists determined final histological diagnoses based on biopsy and LLETZ histology. mRNA-HPV-genotyping for 3 (16, 18, 45) to 8 (16, 18, 31, 33, 35, 45, 52, 58) high-risk types was performed on leftover liquid-based cytology material. The preventive potential of the test-and-treat approach was estimated based on published data, reporting the causative HPV types in cervical cancer tissue from South African women. Treatment was provided as needed.

RESULTS

The HPV positivity rate more than doubled from 3-type (15.2%; 95% CI: 12.6-17.8) to 8-type mRNA (31.5%; 95% CI: 28.8-34.9) combinations, significantly higher among HIV-positive women. CIN3+ prevalence among HIV-positive women (26.4%) was double that of HIV-negative women (12.9%) (p < 0.01). The 6-type combination showed the best balance of sensitivity, specificity and treatment group size, and effectiveness to prevent cervical cancer. A 4-type combination (16, 18, 35, 45) could potentially prevent 77.6% (95% CI: 71.2-84.0) of cervical cancer burden by treating 20% and detecting 41.1% of CIN3 cases in the study group. Similarly, a 6-type combination (16, 18, 31, 33, 35, 45), treating 25% and including 62% of CIN3 cases, might prevent 85% of cervical cancer cases (95% CI: 79.6-90.6) among HIV-positive and negative women.

CONCLUSION

Employing mRNA HPV tests within a test-and-treat approach holds huge promise for targeted cervical cancer prevention in under-screened populations. Testing for mRNA of the 6 highest-risk HPV types in this population and treating them all is projected to effectively prevent progression from CIN3 to invasive cervical cancer while reducing overtreatment in resource-constrained settings.

Test Performance of Cervical Cytology Among Adults With vs Without Human Papillomavirus Vaccination

Importance

Current US cervical cancer screening guidelines do not differ by human papillomavirus (HPV) vaccination status. However, as the positive predictive value (PPV) of a screening test decreases, the risk of a false-positive result increases.

Objective

To evaluate whether HPV vaccination is associated with decreased PPV for abnormal cervical cytology.

Design, Setting, and Participants

This retrospective cohort study conducted via electronic medical record review included eligible patients aged 21 to 35 years who had at least 1 cervical cytology result within a single health system between January 2015 and December 2018. The health system comprises a partnership between an academic health center and a private not-for-profit health center. Patients with abnormal screening cytology and no diagnostic test results were omitted from analysis. Data were analyzed from December 2019 to November 2021.

Exposures

HPV vaccination, defined as receiving at least 1 dose of HPV vaccine. Subgroup analyses were performed for those completing all vaccination doses per Advisory Committee on Immunization Practices guidelines and by age at vaccination initiation, dichotomized as younger than 21 years vs 21 years or older.

Main Outcomes and Measures

PPV of abnormal cervical cytology for risk of cervical intraepithelial neoplasia (CIN) 2 or more severe diagnosis.

Results

A total of 46 988 patients (mean [SD] age, 28.7 [4.5] years; 3058 [6.5%] Asian; 4159 [8.9%] Black or African American; 35 446 [75.4%] White) were included; 15 494 (33.0%) were at least partially vaccinated, and 4289 (9.1%) had abnormal cytology results during the study period. Among the individuals with abnormal cytology, the PPV for CIN 2 or more severe diagnosis was lower among vaccinated individuals (17.4%; 95% CI, 16.4%-18.4%) than unvaccinated individuals (21.3%; 95% CI, 20.4%-22.3%). Among vaccinated individuals, PPV was significantly lower among those completing vaccination (15.9%; 95% CI, 14.9%-17.0%) than those with incomplete vaccination (22.4%; 95% CI, 20.0%-25.0%), especially among those initiating vaccination when younger than 21 years (11.9%; 95% CI, 10.9%-12.9%) vs those initiating at age 21 years or older (30.7%; 95% CI, 27.3%-34.4%).

Conclusions and Relevance

Among a population with relatively low HPV vaccine coverage, the PPV of cervical cytology for CIN 2 or more severe diagnosis was significantly lower among vaccinated individuals. PPV will likely further decrease in the future as a population with higher HPV vaccination coverage ages into screening. Confirmation of these results will call for changes in screening strategies, particularly for completely vaccinated individuals who initiated vaccination when younger than 21 years.

Age-specific effectiveness of primary human papillomavirus screening versus cytology in a cervical cancer screening program: a nationwide cross-sectional study

BACKGROUND

Primary human papillomavirus (HPV) screening is recommended for the detection of cervical intraepithelial neoplasia (CIN) in the general population; however, the triage for HPV-positive women remains a challenge. This study aimed to evaluate the age-specific effectiveness of primary HPV screening versus primary cytology screening for identifying optimal strategies for women of different ages.

METHODS

The dataset of the prevalence round screening was derived from the National Cervical Cancer Screening Program in China. Primary cervical screening protocols included cytology only, HPV testing with cytology triage, and HPV testing with HPV-16/18 genotyping plus cytology triage. The primary outcomes were age-specific detection rate, colposcopy referral rate and positive predictive value (PPV) for CIN2+. Multivariate Poisson regression was used to evaluate the relative effectiveness of HPV testing and cytology according to age groups. The I2 statistic with a random-effect model was used to test the heterogeneity in relative effectiveness of HPV testing versus cytology between age groups.

RESULTS

This study included 1,160,981 women. HPV testing with HPV-16/18 genotyping plus cytology triage significantly increased the CIN2+ detection by 36% (rate ratio [RR]: 1.36, 95% confidential interval [CI] 1.21-1.54) for women aged 35-44 years and by 34% (RR: 1.34, 95% CI 1.20-1.51) for women aged 45-54 years compared with cytology only. HPV testing with cytology triage had similar CIN2+ detection rate compared with cytology only. The PPVs were substantially increased for both HPV testing groups. Among women aged 55-64 years old, HPV testing with HPV-16/18 genotyping plus cytology triage increased the colposcopy referral rate by 19% (RR 1.19, 95% CI 1.10-1.29) compared with cytology only, but did not increase the CIN2+ detection (1.09, 0.91-1.30). The effectiveness of HPV testing with cytology triage did not change in older women. The between-age-group heterogeneity in the effectiveness was statistically significant for HPV testing with HPV-16/18 genotyping plus cytology triage versus cytology only.

CONCLUSIONS

Our results suggested that the effectiveness of primary HPV screening with different triage strategies differed among age groups. HPV testing with HPV-16/18 genotyping plus cytology triage could be used for women aged 35-54 years to detect more lesions, and HPV testing with cytology triage could balance the CIN2+ detection and the number of colposcopies for women aged 55-64 years. Longitudinal data including both prevalence and incidence screening rounds are warranted to assess age-specific triage strategies.

Implementation of a centralized HPV-based cervical cancer screening programme in Tuscany: First round results and comparison with the foregoing Pap-based screening programme

OBJECTIVE

To evaluate performance of the first round of HPV-based screening in Tuscany region and compare it with the prior round of Pap-based screening.

SETTING

Tuscany region of Italy, where HPV-based cervical cancer screening started in 2013, with a strong level of centralization screening tests at the Regional Laboratory for Cancer Prevention (ISPRO).

METHODS

The transition from Pap- to HPV-based screening was initiated for older women and at 3 out of 12 Tuscany Local Health Units (LHUs). Data from the Florence and Grosseto LHUs (about 300,000 women) were analysed and performance screening indicators estimated.

RESULTS

HPV-based indicators recorded good performance, with increased compliance vs. the Pap-based programme. We registered a substantial decrease in waiting times from sampling to test reporting, probably related to the centralization strategy. Since the screening protocol was the same and conducted at a single laboratory, we could hypothesize that the difference in HPV positivity (6.8% in Florence vs. 8.4% in Grosseto) was due to a real difference in HPV prevalence among women of the two LHUs. The transition to HPV-based screening led to a significant increase both in colposcopy referral rate (4.3% vs. 1.2%) and CIN2+ detection rate (8.3‰ vs. 3.4‰).

CONCLUSIONS

HPV-based is more effective in detecting high-grade precancerous and cancerous lesions than Pap-based screening and is characterized by an "anticipatory effect" in the detection of CIN2+ lesions. The transition from Pap-based to HPV-based screening programme should include increased resources dedicated to colposcopy services. Centralization in a laboratory with long experience in this field promotes efficiency of the screening process.

Technological advances: Have they improved standards? Review of outcomes from the Welsh cervical screening programme

OBJECTIVES

Introduction of new technologies into cervical screening programmes has allowed more efficient programmes with less resources. We present an overview of screening technologies introduced into the Cervical Screening Wales programme and their evolution over time.

METHODS

Data from the programme's statistical report were used to evaluate its performance over a 17-year period between 2001/02 and 2017/18.

RESULTS

The introduction of liquid-based cytology has had a substantial impact on reducing inadequate sample rates and on increasing the positive predictive value of cytology. Inadequate rates have increased following the implementation of human papilloma virus testing as a triage test for cytology. Further knock-on effects on standard reporting ranges are expected following the introduction of human papilloma virus testing as the primary screening test. New performance standards have been introduced to better reflect the performance of the programme at a time when disease prevalence is expected to fall as women vaccinated against human papilloma virus reach screening age.

CONCLUSIONS

Improvements to this cervical cancer screening programme as illustrated through performance indicator ranges suggest a major role played by technology.

Modeling Cervical Cancer Screening Strategies With Varying Levels of Human Papillomavirus Vaccination

IMPORTANCE

Cervical cancer screening is a lifesaving intervention, with an array of approaches, including liquid-based cytology (LBC), molecular testing for human papillomavirus (HPV) infection, and combinations via parallel cotesting or sequential triage. Maximizing screening efficacy while minimizing overtreatment is vital, especially when considering how the HPV vaccine will affect the interpretation of results.

OBJECTIVES

To estimate the likely outcomes of different screening modalities and to model how the increasing uptake of the HPV vaccine could affect the interpretation of screening results.

DESIGN, SETTING, AND PARTICIPANTS

This decision analytic model established a simple Markov model to compare the outcomes of different cervical cancer screening modalities on a simulated population of women (aged ≥25 years), considering different levels of HPV vaccination.

MAIN OUTCOMES AND MEASURES

The number of cases of cervical intraepithelial neoplasia (CIN) grade 2 and 3 detected and missed, the number of false positives, and the number of tests required to achieve a given level of accuracy. Positive and negative predictive values of different modalities were simulated under varying levels of HPV vaccination and therefore HPV prevalence.

RESULTS

In a simulated population of 1000 women aged 25 years and older with an HPV prevalence of 2%, HPV-based modalities outperformed LBC-based approaches, detecting 19% more true positives (HPV test sensitivity, 89.9% [95% CI, 88.6%-91.1%]; LBC test sensitivity, 75.5% [95% CI, 66.6%-82.7%]). While cotesting markedly reduced missed cases, detecting 29% more true positives than LBC alone (19.5 [95% CI, 19.3-19.7] per 1000 women screened vs 15.1 [95% CI, 13.3-16.5] per 1000 women screened), it unacceptably increased excess colposcopy referral by 94% (184.4 [95% CI, 181.8-188.0] false positives per 1000 women screened vs 95.1 [95% CI, 93.1-97.0] false positives per 1000 women screened). By contrast, triage testing with reflex screening substantially reduced false positives by a factor of approximately 10 (eg, HPV with LBC triage, 9.6 [95% CI, 9.3-10.0] per 1000 women screened). Over a lifetime of screening, reflex approaches with appropriate test intervals maximized therapeutic efficacy; as HPV vaccination rates increased, HPV-based screening approaches resulted in fewer unnecessary colposcopies than LBC approaches (HPV testing, 80% vaccine coverage: 44.1 [95% CI, 40-45.9] excess colposcopies; LBC testing, 80% vaccine coverage: 96.9 [95% CI, 96.8-97.0] excess colposcopies).

CONCLUSIONS AND RELEVANCE

In this decision analytic model, the effectiveness of cervical cancer screening was dependent on the prevalence of cervical dysplasia and/or HPV infection or vaccination in a population as well as the sensitivity and specificity of various modalities. Although screening is lifesaving, overtesting or modalities inappropriate to the target population may cause significant harm, including overtreatment.

Laser-assisted rapid evaporative ionisation mass spectrometry (LA-REIMS) as a metabolomics platform in cervical cancer screening

Background

The introduction of high-risk human papillomavirus (hrHPV) testing as part of primary cervical screening is anticipated to improve sensitivity, but also the number of women who will screen positive. Reflex cytology is the preferred triage test in most settings but has limitations including moderate diagnostic accuracy, lack of automation, inter-observer variability and the need for clinician-collected sample. Novel, objective and cost-effective approaches are needed.

Methods

In this study, we assessed the potential use of an automated metabolomic robotic platform, employing the principle of laser-assisted Rapid Evaporative Ionisation Mass Spectrometry (LA-REIMS) in cervical cancer screening.

Findings

In a population of 130 women, LA-REIMS achieved 94% sensitivity and 83% specificity (AUC: 91.6%) in distinguishing women testing positive (n = 65) or negative (n = 65) for hrHPV. We performed further analysis according to disease severity with LA-REIMS achieving sensitivity and specificity of 91% and 73% respectively (AUC: 86.7%) in discriminating normal from high-grade pre-invasive disease.

Interpretation

This automated high-throughput technology holds promise as a low-cost and rapid test for cervical cancer screening and triage. The use of platforms like LA-REIMS has the potential to further improve the accuracy and efficiency of the current national screening programme.

Funding

Work was funded by the MRC Imperial Confidence in Concept Scheme, Imperial College Healthcare Charity, British Society for Colposcopy and Cervical Pathology, National Research Development and Innovation Office of Hungary, Waters corporation and NIHR BRC.

Cervical screening: ESGO-EFC position paper of the European Society of Gynaecologic Oncology (ESGO) and the European Federation of Colposcopy (EFC)

This paper summarises the position of ESGO and EFC on cervical screening based on existing guidelines and opinions of a team of lead experts. HPV test is replacing cytology as this offers greater protection against cervical cancer and allows longer screening intervals. Only a dozen of HPV tests are considered as clinically validated for screening. The lower specificity of HPV test dictates the use of triage tests that can select women for colposcopy. Reflex cytology is currently the only well validated triage test; HPV genotyping and p16 immunostaining may be used in the future, although methylation assays and viral load also look promising. A summary of quality assurance benchmarks is provided, and the importance to audit the screening histories of women who developed cancer is noted as a key objective. HPV-based screening is more cost-effective than cytology or cotesting. HPV-based screening should continue in the post-vaccination era. Only a fraction of the female population is vaccinated, and this varies across countries. A major challenge will be to personalise screening frequency according to vaccination status. Still the most important factor for successful prevention by screening is high population coverage and organised screening. Screening with self-sampling to reach under-screened women is promising.

Impact of HPV vaccination on cervical screening performance: a population-based cohort study

BACKGROUND

Human papillomavirus (HPV) vaccination is predicted to lower the positive predictive value (PPV) of cytology.

METHODS

We included 153,250 girls born between 1989 and 1993, resident in Sweden since the introduction of HPV vaccines (October 2006) and attending cervical screening at age 23 years. We assessed their first cytology and following histopathological diagnosis using Swedish National Cervical Screening Registry (NKCx). By linkage with the national Swedish HPV vaccination registry, we determined PPV of abnormal cytology for cervical intraepithelial neoplasia grade 2 or worse (CIN2+) and the differences with 95% confidence intervals (CIs) according to vaccination status.

RESULTS

The PPV of high-grade cytology for CIN2+ was 69.9% (95% CI, 67.9-71.9), 64.9% (95% CI, 59.8-69.8) and 57.4% (95% CI, 50.9-63.7) among women unvaccinated, initiating vaccination at age 17-22 years and initiating vaccination before age 17 years, corresponding to reduction in PPV by 8% (95% CI, 0-15%) and 17% (95% CI, 7-26%) in vaccinated groups after adjustment for birth cohort, respectively.

CONCLUSION

The PPV of cytology for CIN2+ decreased among vaccinated women, and the decrease was stronger for girls vaccinated at younger ages. A switch from cytology to HPV testing might potentially improve the screening performance.

Factors associated with human papillomavirus (HPV) test acceptability in primary screening for cervical cancer: A mixed methods research synthesis

Primary screening for cervical cancer is transitioning from the longstanding Pap smear towards implementation of an HPV-DNA test, which is more sensitive than Pap cytology in detecting high-risk lesions and offers greater protection against invasive cervical carcinomas. Based on these results, many countries are recommending and implementing HPV testing-based screening programs. Understanding what factors (e.g., knowledge, attitudes) will impact on HPV test acceptability by women is crucial for ensuring adequate public health practices to optimize cervical screening uptake. We used mixed methods research synthesis to provide a categorization of the relevant factors related to HPV primary screening for cervical cancer and describe their influence on women's acceptability of HPV testing. We searched Medline, Embase, PsycINFO, CINAHL, Global Health and Web of Science for journal articles between January 1, 1980 and October 31, 2017 and retained 22 empirical articles. Our results show that while most factors associated with HPV test acceptability are included in the Health Belief Model and/or Theory of Planned Behavior (e.g., attitudes, knowledge), other important factors are not encompassed by these theoretical frameworks (e.g., health behaviors, negative emotional reactions related to HPV testing). The direction of influence of psychosocial factors on HPV test acceptability was synthesized based on 14 quantitative studies as: facilitators (e.g., high perceived HPV test benefits), barriers (e.g., negative attitudes towards increased screening intervals), contradictory evidence (e.g., sexual history) and no impact (e.g., high perceived severity of HPV infection). Further population-based studies are needed to confirm the impact of these factors on HPV-based screening acceptability.

Estimation of the individual residual risk of cervical cancer after vaccination with the nonavalent HPV vaccine

BACKGROUND

The nonavalent HPV (9vHPV) vaccine is indicated for active immunisation of individuals from the age of 9 years against cervical, vulvar, vaginal and anal premalignant lesions and cancers causally related to vaccine HPV high risk types 16, 18, 31, 33, 45, 52 and 58, and to the HPV low risk types 6 and 11, causing genital warts.

OBJECTIVE

To estimate the lifetime risk (up to the age of 75 years) for developing cervical cancer after vaccinating a HPV naïve girl (e.g. 9 to 12 years old) with the 9vHPV vaccine in the hypothetical absence of cervical cancer screening.

METHODS

We built Monte Carlo simulation models using historical pre-screening age-specific cancer incidence data and current mortality data from Denmark, Finland, Norway, Sweden and the UK. Estimates of genotype contribution fractions and vaccine efficacy were used to estimate the residual lifetime risk after vaccination assuming lifelong protection.

RESULTS

We estimated that, in the hypothetical absence of cervical screening and assuming lifelong protection, 9vHPV vaccination reduced the lifetime cervical cancer and mortality risks 7-fold with a residual lifetime cancer risks ranging from 1/572 (UK) to 1/238 (Denmark) and mortality risks ranging from 1/1488 (UK) to 1/851 (Denmark). After decades of repetitive cervical screenings, the lifetime cervical cancer and mortality risks was reduced between 2- and 4-fold depending on the country.

CONCLUSION

Our simulations demonstrate how evidence can be generated to support decision-making by individual healthcare seekers regarding cervical cancer prevention.

Human papillomavirus vaccination and the role of herd effects in future cancer control planning: a review

INTRODUCTION

Vaccine herd effects are the indirect protection that vaccinated persons provide to those who remain susceptible to infection, due to the reduced transmission of infections. Herd effects have been an important part of the discourse on how to best implement human papillomavirus (HPV) vaccines and prevent HPV-related diseases.

AREAS COVERED

In this paper, we review the theory of HPV vaccine herd effects derived from mathematical models, give an account of observed HPV vaccine herd effects worldwide, and examine the implications of vaccine herd effects for future cervical cancer screening efforts.

EXPERT COMMENTARY

HPV vaccine herd effects improve the cost-effectiveness of vaccinating preadolescent girls, but contribute to making gender-neutral vaccination less economically efficient. Vaccination coverage and sexual mixing patterns by age are strong determinants of herd effects. Many countries worldwide are starting to observe reductions in HPV-related outcomes likely attributable to herd effects, most notably declining anogenital warts in young men, and declining HPV-16/18 infection prevalence in young unvaccinated women. Policy makers making recommendations for cervical cancer screening will have to consider HPV vaccination coverage and herd effects, as these will affect the positive predictive value of screening and the risk of cervical cancer in unvaccinated women.

The Direct Medical Costs of Diseases Associated with Human Papillomavirus Infection in Manitoba, Canada

BACKGROUND

The total direct cost of screening and treating all human papillomavirus-related diseases (HPV-RD) has not been measured in a single study. Accurate cost estimates are needed to inform decisions on intervention priorities and evaluate the cost-effectiveness of existing programs. We used province-wide clinical, administrative, and accounting databases to measure direct medical costs of HPV infection in Manitoba (Canada).

METHODS

All persons 9 years or older with health insurance coverage in Manitoba between April 2000 and March 2015 were eligible. We identified all persons with an incident HPV-RD and aggregated all medical costs (in 2014 Canadian dollars) related to that condition, including prescription drugs, diagnostic procedures, in-hospital and outpatient treatment, and physician visits.

RESULTS

We found that the median cost of treating a case of anogenital warts was $130. An episode of cervical dysplasia had a median cost of $220, compared to $1300 for an episode of cervical carcinoma in situ. The cost of treating HPV-related invasive cancer varied from $15,000 for cervical cancer to $33,000 for oral cavity cancer. Overall, 80% ($145 million) of the total cost was attributable to HPV infection. Cervical screening and follow-up accounted for $96 million (66%) of all costs and this cost component has declined following the introduction of new screening guidelines.

CONCLUSIONS

Overall, the average direct medical cost of HPV infection was $720 per newborn. The economic burden of HPV remains significant, although changes in cervical screening guidelines, prompted by the introduction of a public HPV vaccine program, appear to have promoted a promising trend towards lower costs.

Trend analysis of the quality indicators for the Brazilian cervical cancer screening programme by region and state from 2006 to 2013

Background

Quality indicators for the Brazilian cervical cancer screening programme can provide a perspective on its effectiveness in Brazilian macro-regions and states. The aim of this study was to perform a trend analysis of the cervical cancer screening program’s quality indicators, according to Brazilian regions and states, from 2006 to 2013.

Methods

Using information from approximately 62,000,000 exams obtained from the Information System of Cervical Cancer Screening (SISCOLO), joinpoint analysis was used to calculate the Annual Percentage Change (APC).

Results

The estimated number of women in the target age group (25–64 years) who underwent Pap testing over a three-year interval was lower than that recommended by international guidelines in the North, Northeast and Midwest regions, and the trends for this indicator remained stationary over the years in all regions of Brazil. Overall, the index of positivity in Brazilian regions and states is below that preconized by the Brazilian National Cancer Institute (INCA). Additionally, the frequencies of unsatisfactory cases are in line with international guidelines but above those preconized by INCA guidelines. All positive cytological diagnoses were lower than those preconized by INCA.

Conclusions

The results show that the cervical cancer screening programme is still far from efficient because most of the quality indicators in Brazilian regions and states are outside of the parameters preconized by national and international organizations.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4047-9) contains supplementary material, which is available to authorized users.

Optimizing secondary prevention of cervical cancer: Recent advances and future challenges

Although human papillomavirus (HPV) vaccines offer enormous promise for the ultimate control and possible elimination of cervical cancer, barriers to uptake and coverage of the vaccine both in high- and low/middle-income settings mean that advances in secondary prevention continue to be essential to prevent unnecessary deaths and suffering from cervical cancer for decades to come. While cytology (the Pap smear) has reduced cervical cancer incidence and prevalence in jurisdictions where it has been systematically implemented in population-based programs-mainly in high-income settings-limitations inherent to this method, and to program delivery, leave many women still vulnerable to cervical cancer. Recent evidence has confirmed that screening based on HPV testing prevents more invasive cervical cancer and precancerous lesions, and offers innovative options such as self-collection of specimens to improve screening uptake broadly. In this paper, we review key advances, future opportunities, and ongoing challenges for secondary prevention of cervical cancer using HPV-based testing.

How will transitioning from cytology to HPV testing change the balance between the benefits and harms of cervical cancer screening? Estimates of the impact on cervical cancer, treatment rates and adverse obstetric outcomes in Australia, a high vaccination coverage country

Primary HPV screening enables earlier diagnosis of cervical lesions compared to cytology, however, its effect on the risk of treatment and adverse obstetric outcomes has not been extensively investigated. We estimated the cumulative lifetime risk (CLR) of cervical cancer and excisional treatment, and change in adverse obstetric outcomes in HPV unvaccinated women and cohorts offered vaccination (>70% coverage in 12-13 years) for the Australian cervical screening program. Two-yearly cytology screening (ages 18-69 years) was compared to 5-yearly primary HPV screening with partial genotyping for HPV16/18 (ages 25-74 years). A dynamic model of HPV transmission, vaccination, cervical screening and treatment for precancerous lesions was coupled with an individual-based simulation of obstetric complications. For cytology screening, the CLR of cervical cancer diagnosis, death and treatment was estimated to be 0.649%, 0.198% and 13.4% without vaccination and 0.182%, 0.056% and 6.8%, in vaccinated women, respectively. For HPV screening, relative reductions of 33% and 22% in cancer risk for unvaccinated and vaccinated women are predicted, respectively, compared to cytology. Without the implementation of vaccination, a 4% increase in treatment risk for HPV versus cytology screening would have been expected, implying a possible increase in pre-term delivery (PTD) and low birth weight (LBW) events of 19 to 35 and 14 to 37, respectively, per 100,000 unvaccinated women. However, in vaccinated women, treatment risk will decrease by 13%, potentially leading to 4 to 41 fewer PTD events and from 2 more to 52 fewer LBW events per 100,000 vaccinated women. In unvaccinated women in cohorts offered vaccination as 12-13 year olds, no change to lifetime treatment risk is expected with HPV screening. In unvaccinated women in cohorts offered vaccination as 12-13 year olds, no change to lifetime treatment risk is expected with HPV screening. HPV screening starting at age 25 in populations with high vaccination coverage, is therefore expected to both improve the benefits (further decrease risk of cervical cancer) and reduce the harms (reduce treatments and possible obstetric complications) associated with cervical cancer screening.

Cervical Cancer Screening in Resource-Constrained Countries: Current Status and Future Directions

Cervical cancer continues to be a major public health problem affecting large numbers of women in many developing countries. Limitations of various screening modalities and the lack of ready availability of a cost-effective point-of-care screening tool have hindered the efficient implementation of population-based screening programs in these settings. It has not proved possible for many countries to adopt cytology as a screening modality due to inadequate infrastructure and trained manpower. However, recent developments, notably design and testing of a low-cost HPV test kit and initiatives by countries like India in developing and putting into operation a framework for large-scale screening of women, have raised hopes that cervical cancer control may be possible even in resource-constrained locations. With the advent of HPV vaccination, primary prevention of cervical cancer also seems a distinct possibility. However, wide availability and acceptability of vaccination is still an unresolved issue for developing countries. The possible future effects of vaccination on test characteristics of various screening strategies also need to be evaluated. This review gathers information on the current status of cervical cancer screening with a special focus on low resource settings. It revisits the strengths and limitations of the available screening modalities for cervical cancer viz. cytology, visual methods and HPV testing, in the context of their applicability in developing countries. In addition, the role of newer HPV-detection methods, for instance DNA, RNA and protein-based techniques, in triage of screen-positive women is discussed. The contemporary issue of impact of HPV vaccination on cervical cancer screening is also addressed briefly. The main highlight of the review is the reference to ‘operational framework guidelines’ for population-based cervical cancer screening, which have recently been formulated and are in the process of being implemented in India. The guidelines may serve as a model for other similar low-resource settings where implementation of cancer screening is desired.

Population-Based Incidence Rates of Cervical Intraepithelial Neoplasia in the Human Papillomavirus Vaccine Era

IMPORTANCE

A substantial effect of human papillomavirus (HPV) vaccines on reducing HPV-related cervical disease is essential before modifying clinical practice guidelines in partially vaccinated populations.

OBJECTIVE

To determine the population-based cervical intraepithelial neoplasia (CIN) trends when adjusting for changes in cervical screening practices that overlapped with HPV vaccination implementation.

DESIGN, SETTING, AND PARTICIPANTS

The New Mexico HPV Pap Registry, which captures population-based estimates of both cervical screening prevalence and CIN, was used to compute CIN trends from January 1, 2007, to December 31, 2014. Under New Mexico Administrative Code, the New Mexico HPV Pap Registry, a statewide public health surveillance program, receives mandatory reporting of all cervical screening (cytologic and HPV testing) and any cervical, vulvar, and vaginal histopathological findings for all women residing in New Mexico irrespective of outcome.

MAIN OUTCOME MEASURES

Prespecified outcome measures included low-grade CIN (grade 1 [CIN1]) and high-grade CIN (grade 2 [CIN2] and grade 3 [CIN3]).

RESULTS

From 2007 to 2014, a total of 13 520 CIN1, 4296 CIN2, and 2823 CIN3 lesions were diagnosed among female individuals 15 to 29 years old. After adjustment for changes in cervical screening across the period, reductions in the CIN incidence per 100 000 women screened were significant for all grades of CIN among female individuals 15 to 19 years old, dropping from 3468.3 to 1590.6 for CIN1 (annual percentage change [APC], -9.0; 95% CI, -12.0 to -5.8; P < .001), from 896.4 to 414.9 for CIN2 (APC, -10.5; 95% CI, -18.8 to -1.2; P = .03), and from 240.2 to 0 for CIN3 (APC, -41.3; 95% CI, -65.7 to 0.3; P = .05). Reductions in the CIN2 incidence were also significant for women 20 to 24 years old, dropping from 1027.7 to 627.1 (APC, -6.3; 95% CI, -10.9 to -1.4; P = .02).

CONCLUSIONS AND RELEVANCE

Population-level decreases in CIN among cohorts partially vaccinated for HPV may be considered when clinical practice guidelines for cervical cancer screening are reassessed. Evidence is rapidly growing to suggest that further increases in raising the age to start screening are imminent, one step toward integrating screening and vaccination.

Cervical cancer screening in women vaccinated against human papillomavirus infection: Recommendations from a consensus conference

In Italy, the cohorts of women who were offered Human papillomavirus (HPV) vaccination in 2007/08 will reach the age (25years) for cervical cancer (CC) screening from 2017. The simultaneous shift from cytology-based screening to HPV test-based screening gives the opportunity for unprecedented reorganisation of CC prevention. The ONS (National Screening Monitoring Centre) Directive and the GISCi (Italian Group for Cervical Screening) identified the consensus conference as the most suitable method for addressing this topic. A summary of consensus recommendations is reported here. The main objective was to define the best screening methods in girls vaccinated against HPV and the knowledge required for defining evidence-based screening strategies. A Jury made recommendations about questions and proposals formulated by a panel of experts representative of Italian scientific societies involved in CC prevention and based on systematic reviews of literature and evidence. The Jury considered changing the screening protocols for girls vaccinated in their twelfth year as appropriate. Tailored screening protocols based on vaccination status could be replaced by "one size fits all" protocols only when a herd immunity effect has been reached. Vaccinated women should start screening at age 30, instead of 25, with HPV test. Furthermore, there is a strong rationale for applying longer intervals for re-screening HPV negative women than the currently recommended 5years, but research is needed to determine the optimal screening time points. For non-vaccinated women and for women vaccinated in their fifteenth year or later, the current protocol should be kept.

Approaches for triaging women who test positive for human papillomavirus in cervical cancer screening

Substantial evidence exists to support the introduction of molecular testing for human papillomavirus (HPV) as the primary technology in cervical cancer screening. While HPV testing is much more sensitive than cytology for detection of high-grade precancerous lesions, it is less specific. To improve efficiency, it is therefore recommended that a specific test (like cytology) be used in triaging HPV positive women to colposcopy. A number of studies have been conducted that support the use of cytology alone or in conjunction with HPV genotyping for triage. The decision to incorporate genotyping also depends on the commercial HPV test that is selected since not all tests provide results for certain individual high-risk types. Regardless of whether policy officials decide to adopt a triage approach that incorporates genotyping, the use of liquid based cytology (LBC) may also improve screening performance by reducing diagnostic delays. With LBC, the same cell suspension from a single collection may be used for HPV testing and a smear can be immediately prepared if HPV status is positive. This was a critical lesson from a community based demonstration project in Montreal (VASCAR study), where conventional cytology exists and specimen co-collection was not permitted for ethical reasons, requiring HPV positive women to return for an additional screening visit prior to colposcopy.

Introduction of molecular HPV testing as the primary technology in cervical cancer screening: Acting on evidence to change the current paradigm

Since being introduced in the 1940s, cervical cytology - despite its limitations - has had unequivocal success in reducing cervical cancer burden in many countries. However, we now know that infection with human papillomavirus (HPV) is a necessary cause of cervical cancer and there is overwhelming evidence from large-scale clinical trials, feasibility studies and real-world experience that supports the introduction of molecular testing for HPV as the primary technology in cervical cancer screening (i.e., "HPV primary screening"). While questions remain about the most appropriate age groups for screening, screening interval and triage approach, these should not be considered barriers to implementation. Many countries are in various stages of adopting HPV primary screening, whereas others have not taken any major steps towards introduction of this approach. As a group of clinical experts and researchers in cervical cancer prevention from across Canada, we have jointly authored this comprehensive examination of the evidence to implement HPV primary screening. Our intention is to create a common understanding among policy makers, agencies, clinicians, researchers and other stakeholders about the evidence concerning HPV primary screening to catalyze the adoption of this improved approach to cervical cancer prevention. With the first cohort of vaccinated girls now turning 21, the age when routine screening typically begins, there is increased urgency to introduce HPV primary screening, whose performance may be less adversely affected compared with cervical cytology as a consequence of reduced lesion prevalence post-vaccination.

Human Papillomavirus and Its Testing Assays, Cervical Cancer Screening, and Vaccination

Human papillomavirus (HPV) was found to be the causative agent for cervical cancer in the 1980s with almost 100% of cervical cancer cases testing positive for HPV. Since then, many studies have been conducted to elucidate the molecular basis of HPV, the mechanisms of carcinogenesis of the virus, and the risk factors for HPV infection. Traditionally, the Papanicolaou test was the primary screening method for cervical cancer. Because of the discovery and evolving understanding of the role of HPV in cervical dysplasia, HPV testing has been recommended as a new method for cervical cancer screening by major professional organizations including the American Cancer Society, American Society for Colposcopy and Cervical Pathology, and the American Society for Clinical Pathology. In order to detect HPV infections, many sensitive and specific HPV assays have been developed and used clinically. Different HPV assays with various principles have shown their unique advantages and limitations. In response to a clear causative relationship between high-risk HPV and cervical cancer, HPV vaccines have been developed which utilize virus-like particles to create an antibody response for the prevention of HPV infection. The vaccines have been shown in long-term follow-up studies to be effective for up to 8 years; however, how this may impact screening for vaccinated women remains uncertain. In this chapter, we will review the molecular basis of HPV, its pathogenesis, and the epidemiology of HPV infection and associated cervical cancer, discuss the methods of currently available HPV testing assays as well as recent guidelines for HPV screening, and introduce HPV vaccines as well as their impact on cervical cancer screening and treatments.

Cervical cancer incidence in British Columbia: Predicting effects of changes from Pap to human papillomavirus screening and of changes in screening participation

Objectives To estimate the impact of increased participation in screening, and of the proposed change from Pap to human papillomavirus screening on the incidence of cervical cancer in British Columbia. Methods For invasive cervical cancer cases diagnosed in British Columbia between 2002 and 2011, data were extracted on age and cancer morphology from the British Columbia Cancer Registry, and Pap screening history was obtained from the British Columbia Cervical Cancer Screening Program database. Only screening performed two to seven years prior to diagnosis was assumed to reduce subsequent risk of cancer. Results from randomized trials of human papillomavirus versus cytology screening and population based estimates of cytology screening were used to estimate the effect of a change in screening test and increases in participation. Results Between 2002 and 2011, there were 1663 cases of cervical cancer reported; 660 (367 squamous and 293 non-squamous) were eligible and screened two to seven years prior to diagnosis. The predicted reduction by changing to human papillomavirus screening was 363 (95% confidence interval = 124-496) representing 22% of all cases. If 50% of subjects not screened two to seven years prior had undergone Pap screening, it is projected that a further 268 cases (16%) could have been prevented; if they had undergone human papillomavirus screening, a further 365 cases (22%) could have been prevented. Conclusions For many women who develop cervical cancer, primary human papillomavirus testing could have substantially reduced their cancer risk. Human papillomavirus rather than Pap testing would further increase the gains from any increases in population screening participation.

Estimating the cost-effectiveness profile of a universal vaccination programme with a nine-valent HPV vaccine in Austria

BACKGROUND

HPV is a major cancer-causing factor in both sexes in the cervix, vulva, vagina, anus, penis, oropharynx as well as the causal factor in other diseases such as genital warts and recurrent respiratory papillomatis. In the context of the arrival of a nonavalent HPV vaccine (6/11/16/18/31/33/45/52/58), this analysis aims to estimate the public health impact and the incremental cost-effectiveness of a universal (girls and boys) vaccination program with a nonavalent HPV vaccine as compared to the current universal vaccination program with a quadrivalent HPV vaccine (6/11/16/18), in Austria.

METHOD

A dynamic transmission model including a wide range of health and cost outcomes related to cervical, anal, vulvar, vaginal diseases and genital warts was calibrated to Austrian epidemiological data. The clinical impact due to the 5 new types was included for cervical and anal diseases outcomes only. In the base case, a two-dose schedule, lifelong vaccine type-specific protection and a vaccination coverage rate of 60% and 40% for girls and boys respectively for the 9-year old cohorts were assumed. A cost-effectiveness threshold of €30,000/QALY-gained was considered.

RESULTS

Universal vaccination with the nonavalent vaccine was shown to reduce the incidence of HPV16/18/31/33/45/52/58 -related cervical cancer by 92%, the related CIN2/3 cases by 96% and anal cancer by 83% and 76% respectively in females and males after 100 years, relative to 75%, 76%, 80% and 74% with the quadrivalent vaccine, respectively. Furthermore, the nonavalent vaccine was projected to prevent an additional 14,893 cases of CIN2/3 and 2544 cases of cervical cancer, over 100 years. Depending on the vaccine price, the strategy was shown to be from cost-saving to cost-effective.

CONCLUSION

The present evaluation showed that vaccinating 60% of girls and 40% of boys aged 9 in Austria with a 9-valent vaccine will substantially reduce the incidence of cervical cancer, CIN and anal cancer compared to the existing strategy. The vaccination strategies performed with the 9-valent vaccine in the current study were all found to be cost-effective compared to the current quadrivalent vaccination strategy by considering a cost-effectiveness threshold of 30,000€/QALY gained.

Discovery of new methylation markers to improve screening for cervical intraepithelial neoplasia grade 2/3

Background

Assessment of DNA promoter methylation markers in cervical scrapings for the detection of cervical intraepithelial neoplasia (CIN) and cervical cancer is feasible, but finding methylation markers with both high sensitivity as well as high specificity remains a challenge. In this study, we aimed to identify new methylation markers for the detection of high-grade CIN (CIN2/3 or worse, CIN2+) by using innovative genome-wide methylation analysis (MethylCap-seq). We focused on diagnostic performance of methylation markers with high sensitivity and high specificity considering any methylation level as positive.

Results

MethylCap-seq of normal cervices and CIN2/3 revealed 176 differentially methylated regions (DMRs) comprising 164 genes. After verification and validation of the 15 best discriminating genes with methylation-specific PCR (MSP), 9 genes showed significant differential methylation in an independent cohort of normal cervices versus CIN2/3 lesions (p < 0.05). For further diagnostic evaluation, these 9 markers were tested with quantitative MSP (QMSP) in cervical scrapings from 2 cohorts: (1) cervical carcinoma versus healthy controls and (2) patients referred from population-based screening with an abnormal Pap smear in whom also HPV status was determined. Methylation levels of 8/9 genes were significantly higher in carcinoma compared to normal scrapings. For all 8 genes, methylation levels increased with the severity of the underlying histological lesion in scrapings from patients referred with an abnormal Pap smear. In addition, the diagnostic performance was investigated, using these 8 new genes and 4 genes (previously identified by our group: C13ORF18, JAM3, EPB41L3, and TERT). In a triage setting (after a positive Pap smear), sensitivity for CIN2+ of the best combination of genes (C13ORF18/JAM3/ANKRD18CP) (74 %) was comparable to hrHPV testing (79 %), while specificity was significantly higher (76 % versus 42 %, p ≤ 0.05). In addition, in hrHPV-positive scrapings, sensitivity and specificity for CIN2+ of this best-performing combination was comparable to the population referred with abnormal Pap smear.

Conclusions

We identified new CIN2/3-specific methylation markers using genome-wide DNA methylation analysis. The diagnostic performance of our new methylation panel shows higher specificity, which should result in prevention of unnecessary colposcopies for women referred with abnormal cytology. In addition, these newly found markers might be applied as a triage test in hrHPV-positive women from population-based screening. The next step before implementation in primary screening programs will be validation in population-based cohorts.

Electronic supplementary material

The online version of this article (doi:10.1186/s13148-016-0196-3) contains supplementary material, which is available to authorized users.

Correlates of women's intentions to be screened for human papillomavirus for cervical cancer screening with an extended interval

Background

High-risk HPV DNA testing has been proposed as a primary tool for cervical cancer screening (HPV-CCS) as an alternative to the Papanicolaou cytology- method. This study describes factors associated with women’s intentions to attend cervical cancer screening if high-risk HPV DNA testing (HPV-CCS) was implemented as a primary screening tool, and if screening were conducted every 4 years starting after age 25.

Methods

This online survey was designed using the Theory of Planned Behaviour to assess factors that impact women’s intentions to attend HPV-CCS among women aged 25–69 upon exit of the HPV FOCAL trial. Univariate and regression analyses were performed to compare the demographic, sexual history, and smoking characteristics between women willing and unwilling to screen, and scales for intention to attend HPV-CCS. A qualitative analysis was performed by compiling and coding the comments section of the survey.

Results

Of the 981 women who completed the survey in full, only 51.4 % responded that they intended to attend HPV-CCS with a delayed start age and extended screening interval. Women who intended to screen were more likely to have higher education (AOR 0.59, 95 % CI [0.37, 0.93]), while both positive attitudes (AOR 1.26, 95 % CI [1.23, 1.30]) and perceived behavior control (AOR 1.06, 95 % CI [1.02, 1.10]) were significant predictors of intention to screen. Among women who provided comments in the survey, a large number of women expressed fears about not being checked more than every 4 years, but 12 % stated that these fears may be alleviated by having more information.

Conclusions

Acceptability of increased screening intervals and starting age could be improved through enhanced education of benefits. Program planners should consider measures to assess and improve women’s knowledge, attitudes and beliefs prior to the implementation of new screening programs to avoid unintended consequences.

HPV immunisation and cervical screening--confirmation of changed performance of cytology as a screening test in immunised women: a retrospective population-based cohort study

Background:

To document the effect of bivalent HPV immunisation on cervical cytology as a screening test and assess the implications of any change, using a retrospective analysis of routinely collected data from the Scottish Cervical Screening Programme (SCSP).

Methods:

Data were extracted from the Scottish Cervical Call Recall System (SCCRS), the Scottish Population Register and the Scottish Index of Multiple Deprivation. A total of 95 876 cytology records with 2226 linked histology records from women born between 1 January 1988 and 30 September 1993 were assessed. Women born in or after 1990 were eligible for the national catch-up programme of HPV immunisation. The performance of cervical cytology as a screening test was evaluated using the key performance indicators used routinely in the English and Scottish Cervical Screening Programmes (NHSCSP and SCSP), and related to vaccination status.

Results:

Significant reductions in positive predictive value (16%) and abnormal predictive value (63%) for CIN2+ and the mean colposcopy score (18%) were observed. A significant increase (38%) in the number of women who had to be referred to colposcopy to detect one case of CIN2+ was shown. The negative predictive value of negative- or low-grade cytology for CIN2+ increased significantly (12%). Sensitivity and specificity, as used by the UK cervical screening programmes, were maintained.

Conclusions:

The lower incidence of disease in vaccinated women alters the key performance indicators of cervical cytology used to monitor the quality of the screening programme. These findings have implications for screening, colposcopy referral criteria, colposcopy practice and histology reporting.

HPV-FASTER: broadening the scope for prevention of HPV-related cancer

Human papillomavirus (HPV)-related screening technologies and HPV vaccination offer enormous potential for cancer prevention, notably prevention of cervical cancer. The effectiveness of these approaches is, however, suboptimal owing to limited implementation of screening programmes and restricted indications for HPV vaccination. Trials of HPV vaccination in women aged up to 55 years have shown almost 90% protection from cervical precancer caused by HPV16/18 among HPV16/18-DNA-negative women. We propose extending routine vaccination programmes to women of up to 30 years of age (and to the 45-50-year age groups in some settings), paired with at least one HPV-screening test at age 30 years or older. Expanding the indications for HPV vaccination and much greater use of HPV testing in screening programmes has the potential to accelerate the decline in cervical cancer incidence. Such a combined protocol would represent an attractive approach for many health-care systems, in particular, countries in Central and Eastern Europe, Latin America, Asia, and some more-developed parts of Africa. The role of vaccination in women aged >30 years and the optimal number of HPV-screening tests required in vaccinated women remain important research issues. Cost-effectiveness models will help determine the optimal combination of HPV vaccination and screening in public health programmes, and to estimate the effects of such approaches in different populations.

Randomized Intervention of Self-Collected Sampling for Human Papillomavirus Testing in Under-Screened Rural Women: Uptake of Screening and Acceptability

BACKGROUND

Our aim was to determine if cervical cancer screening uptake would increase among under-screened women living in rural Ontario, Canada, if at-home self-collected sampling for human papillomavirus (HPV) testing was offered as a primary cervical cancer screening modality, compared to invited papanicolaou (Pap) testing or routine opportunistic screening.

METHODS

Women 30-70 years of age who were overdue for cervical cancer screening were randomized to receive (1) an at-home self-collected HPV kit, (2) a reminder invitation for Pap testing, or (3) standard of care opportunistic screening. The first two arms were also asked demographic and screening history questions. Women randomized to arm 1 were asked about acceptability.

RESULTS

In total, 818 eligible women were identified in a small rural community in Southwestern Ontario: 335 received a self-collected HPV testing kit, 331 received a reminder letter, and 152 received standard of care. In the HPV self-collection arm, 21% (70/335) returned the sample and questionnaire and 11% (37/335) opted to undergo Pap testing. In total, 32% from the HPV self-collection arm, 15% (51/331) from the Pap invitation arm, and 8.5% (13/152) with standard of care were screened. Women receiving the self-collected HPV kit were 3.7 (95% confidence interval 2.2-6.4) times more likely to undergo screening compared to the standard of care arm. In the HPV self-sampling arm, 80% (56/70) said they would be very likely to choose self-collected sampling in the future.

CONCLUSIONS

Providing self-collected sampling for HPV testing was more effective than sending reminder letters to increase screening coverage in under-screened women.

Cervical cancer screening of HPV vaccinated populations: Cytology, molecular testing, both or none

Cervical cancer control includes primary prevention through vaccination to prevent human papillomavirus (HPV) infection and secondary prevention through screening to detect and treat cervical precancerous lesions. This review summarizes the evidence for the population impact of vaccines against oncogenic HPV types in reducing the prevalence of cervical precancerous lesions. We examine the gradual shift in screening technology from cervical cytology alone to cytology and HPV cotesting, and finally to the recognition that HPV testing can serve alone as the new screening paradigm, particularly in the initial post-vaccination era. We should expect an impact on screening performance and practices, as cohorts of HPV-vaccinated girls and adolescents reach cervical cancer screening age. In preparation for changes in the screening paradigm for the vaccination era, we propose that policymaking on cervical cancer screening should mirror current practices with other cancers as benchmarks. Cervical precancerous lesions will become a very rare condition following the widespread implementation of HPV vaccines with broader coverage in the number of preventable oncogenic types. Irrespective of screening technology, the false positive results will far outnumber the true positive ones, a tipping point that will herald a new period when the harms from cervical cancer screening will outweigh its benefits. We present a conceptual framework to guide decision making when we reach this point within 25-30 years.

Historical Analysis of the Brazilian Cervical Cancer Screening Program from 2006 to 2013: A Time for Reflection

Background

The Cervical Cancer Database of the Brazilian National Health Service (SISCOLO) contains information regarding all cervical cytological tests and, if properly explored, can be used as a tool for monitoring and managing the cervical cancer screening program. The aim of this study was to perform a historical analysis of the cervical cancer screening program in Brazil from 2006 to 2013.

Material and Methods

The data necessary to calculate quality indicators were obtained from the SISCOLO, a Brazilian health system tool. Joinpoint analysis was used to calculate the annual percentage change.

Results

We observed important trends showing decreased rates of low-grade squamous intraepithelial lesions (LSIL) and high-grade squamous intraepithelial lesions (HSIL) and an increased rate of rejected exams from 2009 to 2013. The index of positivity was maintained at levels below those indicated by international standards; very low frequencies of unsatisfactory cases were observed over the study period, which partially contradicts the low rate of positive cases. The number of positive cytological diagnoses was below that expected, considering that developed countries with low frequencies of cervical cancer detect more lesions annually.

Conclusions

The evolution of indicators from 2006 to 2013 suggests that actions must be taken to improve the effectiveness of cervical cancer control in Brazil.

HPV DNA testing with cytology triage in cervical cancer screening: Influence of revealing HPV infection status

BACKGROUND

Knowledge of cervical human papillomavirus (HPV) status might influence a cytotechnician's assessment of cellular abnormalities. The authors compared original cytotechnicians' Papanicolaou (Pap) readings for which HPV status was concealed with Pap rereads for which HPV status was revealed separately for 3 screening populations.

METHODS

Previously collected cervical Pap smears and clinical data were obtained from the Canadian Cervical Cancer Screening Trial (study A), the Democratic Republic of Congo Community-Based Screening Study (study B), and the Brazilian Investigation into Nutrition and Cervical Cancer Prevention (study C). Smears were reread with knowledge of HPV status for all HPV-positive women as well as a sample of HPV-negative women. Diagnostic performance of Pap cytology was compared between original readings and rereads.

RESULTS

A total of 1767 Pap tests were reread. Among 915 rereads for HPV-positive women, the contrast between "revealed" and "concealed" Pap readings demonstrated revisions from negative to positive results for 109 women (cutoff was atypical squamous cells of undetermined significance or worse) and 124 women (cutoff was low-grade squamous intraepithelial lesions [LSIL] or worse). For a disease threshold of cervical intraepithelial neoplasia of grade 2 or worse, specificity significantly declined at the atypical squamous cells of undetermined significance cutoff for studies A (86.6% to 75.3%) and C (42.5% to 15.5%), and at the LSIL cutoff for study C (61.9% to 37.6%). Sensitivity remained nearly unchanged between readings, except in study C, in which reread performance was superior (91.3% vs 71.9% for the LSIL cutoff).

CONCLUSIONS

A reduction in the diagnostic accuracy of Pap cytology was observed when revealing patients' cervical HPV status, possibly due to a heightened awareness of potential abnormalities, which led to more false-positive results.

Primary screening for cervical cancer based on high-risk human papillomavirus (HPV) detection and HPV 16 and HPV 18 genotyping, in comparison to cytology

OBJECTIVES

The objective of the present study is to assess the performance of a high-risk human papillomavirus (HR-HPV) DNA test with individual HPV-16/HPV-18 genotyping as a method for primary cervical cancer screening compared with liquid-based cytology (LBC) in a population of Greek women taking part in routine cervical cancer screening.

METHODS

The study, conducted by the "HEllenic Real life Multicentric cErvical Screening" (HERMES) study group, involved the recruitment of 4,009 women, aged 25-55, who took part in routine cervical screening at nine Gynecology Departments in Greece. At first visit cervical specimens were collected for LBC and HPV testing using the Roche Cobas 4800 system. Women found positive for either cytology or HPV were referred for colposcopy, whereas women negative for both tests will be retested after three years. The study is ongoing and the results of the first screening round are reported herein.

RESULTS

Valid results for cytology and HPV testing were obtained for 3,993 women. The overall prevalence of HR-HPV was 12.7%, of HPV-16 2.7% and of HPV-18 1.4%. Of those referred for colposcopy, cervical intraepithelial neoplasia grade 2 or worse (CIN2+) was detected in 41 women (1.07%). At the threshold of CIN2+, cytology [atypical squamous cells of undetermined significance (ASC-US) or worse] and HPV testing showed a sensitivity of 53.7% and 100% respectively, without change between age groups. Cytology and HPV testing showed specificity of 96.8% and 90.3% respectively, which was increased in older women (≥30) in comparison to younger ones (25-29). Genotyping for HPV16/18 had similar accuracy to cytology for the detection of CIN2+ (sensitivity: 58.5%; specificity 97.5%) as well as for triage to colposcopy (sensitivity: 58.5% vs 53.7% for cytology).

CONCLUSION

HPV testing has much better sensitivity than cytology to identify high-grade cervical lesions with slightly lower specificity. HPV testing with individual HPV-16/HPV-18 genotyping could represent a more accurate methodology for primary cervical cancer screening in comparison to liquid-based cytology, especially in older women.

Invited commentary: multiple human papillomavirus infections and type replacement-anticipating the future after human papillomavirus vaccination

Prophylactic human papillomavirus (HPV) vaccination with 3 doses of either of 2 commercially available vaccines is highly efficacious in preventing infections with the most carcinogenic types of HPV (HPV 16 and HPV 18) at the cervix and other anatomical sites at which HPV-related cancers develop. Concern has been raised that eradicating the most virulent HPV types, 16 and 18, could result in 1 or more of the types that are not targeted by the vaccine occupying the ecological niche created by the elimination of these types, referred to as type replacement. In this issue of the Journal, Yang et al. (Am J Epidemiol. 2014;180(11):1066-1075) report on concurrent infections with multiple HPV types in unvaccinated women who underwent cervical screening in New Mexico (December 2007-April 2009) to identify possible interactions between HPV types, which if present could suggest the possibility of type replacement. Consistent with previous reports, they show minimal type-specific interactions among women with normal cytology, which they consider an indication that type replacement of HPV 16/18 is unlikely to be an issue in the general population postvaccination. Type replacement may be of less concern with the introduction of multivalent vaccines that include most of the carcinogenic HPV types; continued surveillance postvaccination should improve our understanding of the impact of HPV vaccination on type distribution and screening performance.

The Tahoe Study: bias in the interpretation of Papanicolaou test results when human papillomavirus status is known

CONTEXT

Knowledge of human papillomavirus (HPV) status is expected to bias the morphologic evaluation of Papanicolaou (Pap) test results.

OBJECTIVE

To characterize Pap test result interpretive bias when the HPV status is known at the microscopic evaluation.

DESIGN

Forty HPV-positive liquid-based Pap test results initially interpreted as negative for squamous intraepithelial lesion or malignancy were selected from a quality assurance program, separated into 2 groups of 20 slides each, and circulated in 2 groups to 22 members of the College of American Pathologists Cytopathology Committee. Each member reviewed each case and indicated whether the result was negative for squamous intraepithelial lesion or malignancy or was an epithelial cell abnormality (ECA). The participants assessed the severity of ECAs using the Bethesda System. The participants were not informed of the HPV status in the initial review round. Each group of 20 slides was then distributed to the opposite group (to avoid slide recall), and the participants were informed that all slides were from patients who were high-risk HPV positive. Differences in the responses between groups were analyzed by χ(2) test and Cochran-Mantel-Haenszel test at the .05 significance level.

RESULTS

Without knowledge of the HPV status, slides were more often categorized as negative for squamous intraepithelial lesion or malignancy and less likely identified as an ECA (P < .001). There was an increase across all categories of ECAs in the biased responses compared with the unbiased responses (P = .002).

CONCLUSIONS

Knowledge of positive HPV status biases morphologic Pap test result interpretation. If the HPV status is positive, observers are more likely to report a Pap test result as abnormal across all categories of ECAs.

Human papillomavirus vaccines: key factors in planning cost-effective vaccination programs

Prophylactic HPV vaccines hold tremendous potential for reducing cervical and non-cervical HPV-related disease burden worldwide. To maximize on this potential, policy officials will need to carefully consider available evidence, existing uncertainties and the cost-effectiveness of mass HPV vaccination programs in the context of their respective nations and/or regions. Proper harmonization of primary prevention strategies with secondary prevention efforts will also be important. Decisions following such considerations may ultimately depend on programmatic objectives, infrastructure and available resources. Continued research and surveillance surrounding HPV vaccination will be essential for filling current knowledge gaps, and forcing ongoing reconsiderations of selected immunization strategies.

Influence of Brucella abortus lipopolysaccharide as an adjuvant on the immunogenicity of HPV-16 L1VLP vaccine in mice

Brucella abortus lipopolysaccharide (LPS) has less toxicity and no pyrogenic properties in comparison with other bacterial LPS. It is a toll-like receptor 4 agonist and has been shown to have the potential use as a vaccine adjuvant. In this study, the immunostimulatory properties of LPS from smooth and rough strains of B. abortus (S19 and RB51) as adjuvants were investigated for the human papillomavirus type 16 (HPV16) L1 virus-like particles (L1VLPs) vaccines. C57BL/6 mice were immunized subcutaneously three times either with HPV-16 L1VLPs alone, or in combination with smooth LPS (S-LPS), rough LPS (R-LPS), aluminum hydroxide or a mixture of them as adjuvant. The humoral immunity was evaluated by measuring the specific and total IgG levels, and also the T-cell immune response of mice was evaluated by measuring different cytokines such as IFN-γ, TNF-α, IL-4, IL-10 and IL-17. Results showed that serum anti-HPV16 L1VLP IgG antibody titers was significantly higher in mice immunized with a combination of VLPs and R-LPS or S-LPS compared with other immunized groups. Co-administration of HPV-16 L1VLPs with R-LPS elicited the highest levels of splenocytes cytokines (IFN-γ, IL-4, IL-17 and TNF-α) and also effectively induced improvement of a Th1-type cytokine response characterized with a high ratio of IFN-γ/IL-10. The data indicate that B. abortus LPS particularly RB51-LPS enhances the immune responses to HPV-16 L1VLPs and suggests its potential as an adjuvant for the development of a potent prophylactic HPV vaccine and other candidate vaccines.

HPV testing with cytology triage for cervical cancer screening in routine practice

OBJECTIVE

The purpose of this study was to evaluate the feasibility and effectiveness of Viral Testing Alone with Pap (Papanicolaou) Triage for Screening Cervical Cancer in Routine Practice (VASCAR) in a publicly funded university-affiliated hospital in Montreal, Canada.

STUDY DESIGN

Women who are 30-65 years old are screened with the Hybrid Capture-2 assay. Women with negative results are retested at 3-year intervals; women with positive results are triaged with conventional cytologic methods. Women with Papanicolaou positive test results (≥atypical squamous cells of undetermined significance) are referred to colposcopy; women with Papanicolaou negative test results are retested with Hybrid Capture-2 assay and a Papanicolaou test in 1 year. Results were compared with a historic era (annual cytology with ≥atypical squamous cells of undetermined significance threshold for colposcopy referral) in the 3 years before VASCAR.

RESULTS

VASCAR included 23,739 eligible women, among whom 1646 women (6.9%) tested positive for the human papillomavirus (HPV). Because of the need for subsequent sampling for cytologic testing, follow-up evaluation for cytologic triage was relatively poor; only 46% and 24% of HPV-positive women were Papanicolaou-triaged and underwent biopsy, respectively. Protocol violations occurred mainly in the early phases of implementation (12%). Detection of high-grade cervical intraepithelial neoplasia increased nearly 3-fold (rate ratio, 2.78; 95% confidence interval [CI], 2.1-3.7) during VASCAR, mostly because of a doubling in the rate of high-grade cervical intraepithelial neoplasia (34.0%; 95% CI, 21.2-48.8) compared with the historic cytology-only era (16.3%; 95% CI, 13.2-19.8). VASCAR reduced the median time to colposcopy from a positive screen from 11 months (95% CI, 10.48-11.50) to 3 months (95% CI, 2.64-3.80).

CONCLUSION

VASCAR is feasible; however, it requires cosampling for HPV and cytology and for continuous education of healthcare providers of the HPV-Papanicolaou triage protocol. Efficacy in disease detection and reduction in time to colposcopy referrals compared with the historic cytology era is encouraging but should be considered preliminary because of the small number of patients who were tested.