What cervical screening is appropriate for women who have been vaccinated against high risk HPV? A simulation study

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.

A systematic review of the cost-effectiveness of interventions to increase cervical cancer screening among underserved women in Europe

BACKGROUND

This study aimed to conduct a systematic review of the cost-effectiveness studies of interventions to increase cervical cancer screening uptake rates in underserved women in Europe.

METHODS

A search of Embase, Medline, Global Health, PsychINFO, and NHS Economic Evaluation Database was conducted for studies published between January 2000 and September 2022. Studies were eligible if they analysed the cost-effectiveness of any interventions to improve participation in cervical cancer screening among underserved women of any age eligible to participate in cervical cancer screening in European countries, in any language. Study characteristics and cost-effectiveness results were summarised. Study quality was assessed using the Drummond Checklist, and methodological choices were further compared.

RESULTS

The searches yielded 962 unique studies, with 17 of these (from twelve European countries) meeting the eligibility criteria for data extraction. All studies focused on underscreened women as an overarching group, with no identified studies focusing on specific subgroups of underserved women. Generally, self-HPV testing and reminder interventions were shown to be cost-effective to increase the uptake rates. There was also research showing that addressing access issues and adopting different screening modalities could be economically attractive in some settings, but the current evidence is insufficient due to the limited number of studies.

CONCLUSION

This systematic review has revealed a gap in the literature on the cost-effectiveness of interventions to improve uptake rates of cervical cancer screening through tailored provision for specific groups of underserved women.

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.

Baseline knowledge on risk factors, symptoms and intended behavior of women and men towards screening and treatment of cervical cancer in rural Uganda: a cross-sectional study

BACKGROUND

Knowledge of risk factors and symptoms of cervical cancer has been found to promote uptake of screening of cervical cancer. Most interventions targeted women without much involvement of men (husbands/decision makers) who are often decision makers in many low- and middle-income countries. This study aimed at assessing baseline knowledge and intended behavior of both women and men to enable design specific targeted messages to increase uptake of cervical cancer screening and promote early detection of women with symptoms.

METHODS

This cross-sectional study was conducted in two districts in Western Uganda using the modified African Women Awareness of CANcer (AWACAN) questionnaire. Women aged 30-49 years and their husbands/decision makers were interviewed. Knowledge on risk factors and symptoms, intended behavior and barriers towards participation in cervical cancer screening and treatment were assessed. Descriptive and logistic regression analyses were done to establish the association between knowledge levels and other factors comparing women to men.

RESULTS

A total of 724 women and 692 men were enrolled. Of these, 71.0% women and 67.2% men had ever heard of cervical cancer and 8.8% women had ever been screened. Knowledge of risk factors and symptoms of cervical cancer was high and similar for both women and men. Lack of decision making by women was associated with low knowledge of risk factors (X2 = 14.542; p = 0.01), low education (X2 = 36.05, p < 0.01) and older age (X2 = 17.33, p < 0.01). Men had better help seeking behavior than women (X2 = 64.96, p < 0.01, OR = 0.39, 95% CI: 0.31-0.50) and were more confident and skilled in recognising a sign or symptom of cervical cancer (X2 = 27.28, p < 0.01, OR = 0.52, CI (0.40-0.67).

CONCLUSION

The baseline knowledge for cervical cancer was high in majority of participants and similar in both women and men. Their intended behavior towards screening was also positive but screening uptake was very low. This study suggests developing messages on multiple interventions to promote screening behavior in addition to education, consisting of male involvement, women empowerment and making services available, accessible and women friendly.

Social Norms in Cervical Cancer Screening

Cancer screening aims to check the body for cancer before symptoms develop. Social norms theory suggests people falsely perceive the attitudes and/or behaviours of similar others to be different from their own and correcting these perceptions can lead to behaviour change. Across two studies, we tested if women underestimate peer levels of cervical screening behaviour and whether a social norms manipulation increases intention to attend cervical cancer screening. In study 1, participants completed a survey on cervical cancer screening norms. In study 2, participants were randomised to receive no norm information, norm information, or norm information plus statement on value of norms in decision making. In study 1, participant estimates of peer level of cervical screening behaviour were significantly lower than nationally reported levels. In study 2, a social norm plus value statement intervention led to stronger intentions to attend screening. This effect was consistent across demographic factors and screening status. Participants significantly underestimate rates of cervical screening behaviour in their peers. A brief, online social norms plus values manipulation increased intentions to attend cervical cancer screening across all groups.

Canadian Guideline on the Management of a Positive Human Papillomavirus Test and Guidance for Specific Populations

The purpose of this paper is to provide evidence-based guidance on the management of a positive human papilloma virus (HPV) test and to provide guidance around screening and HPV testing for specific patient populations. The guideline was developed by a working group in collaboration with the Gynecologic Oncology Society of Canada (GOC), Society of Colposcopists of Canada (SCC), and the Canadian Partnership Against Cancer. The literature informing these guidelines was obtained through a systematic review of relevant literature by a multi-step search process led by an information specialist. The literature was reviewed up to July 2021 with manual searches of relevant national guidelines and more recent publications. The quality of the evidence and strength of recommendations were developed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework. The intended users of this guideline include primary care providers, gynecologists, colposcopists, screening programs, and healthcare facilities. The implementation of the recommendations will ensure an optimum implementation of HPV testing with a focus on the management of positive results. Recommendations for appropriate care for underserved and marginalized groups are made.

Managing an extension of screening intervals: Avoiding boom and bust in health care workloads

Extending screening intervals in ongoing cancer screening programmes can lead to challenging year-on-year variations in the number of screening tests. We explored how such variation could be diminished with a managed transition to the extended interval. We defined three extension scenarios: immediate extension for the entire target population; stepped transition by birth cohort; and gradual transition by reducing the number of available screening appointments. These were compared to a situation in which the interval remains unchanged in a demographic model covering a 15-year period. The model was populated with observed parameters from England, a real-world setting recommending cervical screening with 3-year intervals at age 25-49 and 5-year intervals at age 50-64. Informed by typical changes currently considered by several European programmes including the programme in England, we explored the effect on screening test numbers of an extension of the 3-year interval to 5 years for women younger than 50. All three extension scenarios resulted in similar cumulative numbers of screening tests, which were about 30% lower compared to a situation in which the interval would remain unchanged. However, the year-on-year variation in the number of screening tests varied between the scenarios. This variation was around 4-fold for the immediate scenario. In the stepped scenario, the yearly numbers could differ by around 20%, whereas in the gradual scenario they were virtually constant. A managed interval extension, transitioning different groups of the target population at different times, can substantially reduce the yearly variation in screening workload without increasing the total number of screening tests in the long term.

Knowledge, attitude and practice towards cervical cancer screening among women living with human immunodeficiency virus: Implication for prevention strategy uptake

AIM

To explore the knowledge, attitude and practices of cervical cancer screening among HIV-infected women in public health facilities in Lusaka, Zambia.

DESIGN

Cross-sectional study.

METHODS

The study was conducted from 1st January 2020 to 28th February 2020. We used a structured questionnaire for data collection. The Structural Equation Modelling (SEM) was used to analyse relationships among latent variables (knowledge, attitude and practice).

RESULTS

The overall knowledge, attitude, and practice scores of cervical cancer screening among women living with HIV were 6.86/11 (62.4%), 6.41/7 (91.6%) and 2.92/8 (36.5%), respectively. Overall, knowledge was positively and significantly associated with attitude (r = .53, p < .001) and practice (r = .38, p < 0.001). Additionally, attitude and practice were significantly associated (r = 0.29, p < .001). Our findings support the reinforcement of current public health interventional programmes to improve the knowledge about cervical cancer and screening uptake.

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.

Do reasoned action approach variables mediate relationships between demographics and cervical cancer screening intentions or behaviour? An online study of women from the UK

OBJECTIVE

In the UK, approximately 3,200 women are diagnosed with cervical cancer each year. Regular screening is one of the best ways to prevent cervical cancer from developing, yet screening rates are declining and vary by sociodemographic variables. The present stratified online study aimed to investigate relationships between sociodemographic factors and screening intentions and past behaviour. Reasoned Action Approach (RAA) variables were assessed as potential mediators.

METHODS

In total, 500 women living in the UK were recruited via an online research recruitment website to an online cross-sectional survey. Participant recruitment was stratified by age, socioeconomic status and ethnicity to ensure adequate representation of each strata. Participants completed measures on RAA variables (affective attitudes, cognitive attitudes, injunctive norms, descriptive norms, capability, autonomy, and intention) as well as screening past behaviour.

RESULTS

Among the demographic variables, age, ethnicity and deprivation were significantly related to screening intention. Younger women, those from less deprived areas, along with white women were more likely to report higher intentions to attend screening. Past behaviour was significantly negatively predicted by deprivation only, indicating that individuals from less deprived areas were more likely to be up to date with their screening. Both intention and past behaviour were significantly positively correlated with all RAA variables. Capability and cognitive attitude partially mediated the relationship between age and intention and fully mediated the relationship between ethnicity and intention. Capability fully mediated the relationships between deprivation and intention and between deprivation and past behaviour.

CONCLUSION

Intentions toward attending cervical cancer screening are related to age, ethnicity, and level of deprivation, with older women and those from areas of greater deprivation and ethnic minority groups reporting lower intentions. Capability (confidence engaging in cervical screening) and cognitive attitudes (how useful/beneficial screening is seen to be) are key variables to target to promote cervical screening attendance and reduce potential inequalities.

COVID-19 disruption to cervical cancer screening in England

INTRODUCTION

In England, routine invitations for cervical screening were reduced between April 2020 and June 2020 due to the COVID-19 pandemic. We quantify the impact of COVID-19 disruptions on attendance and excess diagnoses of cervical cancer (CC).

METHODS

Using Public Health England CC screening data on laboratory samples received in 2018 as a baseline we quantify the reduction in screening attendances due to the COVID-19 pandemic between April 2020 and March 2021 for women aged 25-64. We model the impact on excess CC diagnoses assuming once invitations resume 87.5% of women attend within 12 months and 12.5% delay screening for 3 or 5 years (depending on age).

RESULTS

The number of samples received at laboratories was 91% lower than expected during April, 85% during May and 43% during June 2020 compared to the same period in 2018. Although on average laboratories received 12.6% more samples between August 2020 and April 2021 than over the same months in 2018, by April 2021 there was a short fall of 200,949 samples (6.4% fewer than in 2018). An excess of 41 CC (4.0 per 100,000 women with a maximum screening delay of 12 months) are predicted to occur among the estimated 1,024,794 women attending this screening round with a delay. An excess of 60 CC (41.0 per 100,000 women) are predicted to occur among the estimated 146,391 women who do not attend this screening round.

CONCLUSION

Prompt restoration of cervical screening services limited the impact on excess CC diagnoses. However, in 2020 a 6.4% shortfall of screening samples was observed. Every effort should be made to reassure these women that services are open and safe to attend.

The impact of catch-up bivalent human papillomavirus vaccination on cervical screening outcomes: an observational study from the English HPV primary screening pilot

BACKGROUND

In England, bivalent vaccination (Cervarix) against high-risk human papillomavirus (HR-HPV) genotypes 16/18 was offered in a population-based catch-up campaign in 2008-2010 to girls aged 14-17 years. These women are now entering the national cervical screening programme. We determined the impact of catch-up bivalent vaccination on their screening outcomes.

METHODS

We studied the overall and genotype-specific screening outcomes in 108,138 women aged 24-25 (offered vaccination) and 26-29 years (not offered vaccination) included in the English HPV screening pilot between 2013 and 2018.

RESULTS

At 24-25 years, the detection of high-grade cervical intraepithelial neoplasia (CIN2+) associated with HPV16/18 decreased from 3 to 1% (p < 0.001), with estimated vaccine effectiveness of 87% (95% CI: 82-91%). The detection of any CIN2+ halved from 6 to 3% (p < 0.001), with an estimated vaccine effectiveness of 72% (95% CI: 66-77%). The positive predictive value of a colposcopy for CIN2+ decreased for both low-grade (p < 0.001) and high-grade (p = 0.02) abnormalities on triage cytology. The decreases in screen-detected abnormalities at age 26-29 were of a substantially smaller magnitude.

CONCLUSIONS

These data confirm high effectiveness of bivalent HPV vaccination delivered through a population-based catch-up campaign in England. These findings add to the rationale for extending screening intervals for vaccinated cohorts.

Age-specific outcomes from the first round of HPV screening in unvaccinated women: Observational study from the English cervical screening pilot

OBJECTIVE

To report detailed age-specific outcomes from the first round of an English pilot studying the implementation of high-risk human papillomavirus (HR-HPV) testing in primary cervical screening.

DESIGN

Observational study with screening in 2013-2016, followed by two early recalls and/or colposcopy until the end of 2019.

SETTING

Six NHS laboratory sites.

POPULATION

A total of 1 341 584 women undergoing screening with HR-HPV testing or liquid-based cytology (LBC).

METHODS

Early recall tests and colposcopies were recommended, depending on the nature of the screening-detected abnormality.

MAIN OUTCOME MEASURES

We reported standard screening process indicators, e.g. proportions with an abnormality, including high-grade cervical intraepithelial neoplasia (CIN2+) or cancer, and the positive predictive value (PPV) of colposcopy for CIN2+, by screening test and age group.

RESULTS

Among unvaccinated women screened with HR-HPV testing at age 24-29 years, 26.9% had a positive test and 10.4% were directly referred to colposcopy following cytology triage, with a PPV for CIN2+ of 47%. At 50-64 years of age, these proportions were much lower: 5.3%, 1.2% and 27%, respectively. The proportions of women testing positive for HR-HPV without cytological abnormalities, whose early recall HR-HPV tests returned negative results, were similar across the age spans: 54% at 24-29 years and 55% at 50-64 years. Two-thirds of infections at any age were linked to non-16/18 genotypes. Among women with CIN2, CIN3 or cervical cancer, however, the proportion of non-16/18 infections increased with age. As expected, the detection of abnormalities was lower following screening with LBC.

CONCLUSIONS

These data provide a reliable reference for future epidemiological studies, including those concerning the effectiveness of HPV vaccination.

TWEETABLE ABSTRACT

Data from the English pilot study provide a comprehensive overview of abnormalities detected through HPV screening.

Extension of cervical screening intervals with primary human papillomavirus testing: observational study of English screening pilot data

OBJECTIVES

To provide updated evidence about the risk of cervical intraepithelial neoplasia grade 3 or higher (CIN3+) and cervical cancer after a negative human papillomavirus (HPV) test in primary cervical screening, by age group and test assay.

DESIGN

Observational study.

SETTING

Real world data from the English HPV screening pilot's first and second rounds (2013-16, follow-up to end of 2019).

PARTICIPANTS

1 341 584 women.

INTERVENTIONS

Cervical screening with HPV testing or liquid based cytological testing (cytology or smear tests). Women screened with cytology were referred to colposcopy after high grade cytological abnormalities or after borderline or low grade abnormalities combined with a positive HPV triage test. Women screened with HPV testing who were positive were referred at baseline if their cytology triage test showed at least borderline abnormalities or after a retest (early recall) at 12 and 24 months if they had persistent abnormalities.

MAIN OUTCOME MEASURES

Detection of CIN3+ and cervical cancer after a negative HPV test.

RESULTS

For women younger than 50 years, second round detection of CIN3+ in this study was significantly lower after a negative HPV screen in the first round than after cytology testing (1.21/1000 v 4.52/1000 women screened, adjusted odds ratio 0.26, 95% confidence interval 0.23 to 0.30), as was the risk of interval cervical cancer (1.31/100 000 v 2.90/100 000 woman years, adjusted hazard ratio 0.44, 0.23 to 0.84). Risk of an incident CIN3+ detected at the second screening round in the pilot five years after a negative HPV test was even lower in women older than 50 years, than in three years in women younger than 50 years (0.57/1000 v 1.21/1000 women screened, adjusted odds ratio 0.46, 0.27 to 0.79). Women with negative HPV tests at early recall after a positive HPV screening test without cytological abnormalities had a higher detection rate of CIN3+ at the second routine recall than women who initially tested HPV negative (5.39/1000 v 1.21/1000 women screened, adjusted odds ratio 3.27, 95% confidence interval 2.21 to 4.84). Detection after a negative result on a clinically validated APTIMA mRNA HPV test was similar to that after clinically validated cobas and RealTime DNA tests (for CIN3+ at the second round 1.32/1000 v 1.14/1000 women screened, adjusted odds ratio 1.05, 0.73 to 1.50).

CONCLUSIONS

These data support an extension of the screening intervals, regardless of the test assay used: to five years after a negative HPV test in women aged 25-49 years, and even longer for women aged 50 years and older. The screening interval for HPV positive women who have negative HPV tests at early recall should be kept at three years.

Acceleration of cervical cancer diagnosis with human papillomavirus testing below age 30: Observational study

Several international cervical screening guidelines advise against using high-risk human papillomavirus (HR-HPV) testing in women younger than 30. The rationale for this in young women, lies in the potential for additional detection of both low-grade and high-grade cervical intraepithelial neoplasia (CIN) leading to unnecessary treatments without reducing the burden of cervical cancer. We studied 56 544 women screened at 24 to 29 with HR-HPV testing and 116 858 screened with liquid-based cytology (LBC) in the English HPV screening pilot. They were compared to 528 460 women screened at the age of 30 to 49. We studied the detection of cervical cancer and CIN2/3 across two consecutive screening rounds 3 years apart. At 24 to 29, a positive HR-HPV test detected more cases of cervical cancer in the prevalence round than did a positive LBC test (1.36/1000 screened vs 0.82/1000, ORadj : 1.61, 95% CI: 1.18-2.19). In women with a negative HR-HPV test, cervical cancer was diagnosed before or at the incidence round in 0.07/1000. After a negative LBC test, cancer detection reached 0.47/1000 and 40% of these cases were diagnosed at FIGO stage IB+. HR-HPV testing increased the detection of CIN2/3 diagnoses in two consecutive rounds combined by 30% (71.9/1000 vs 55.2/1000). The patterns of detection of cervical cancer and CIN2/3 were almost identical at older ages. These data support using HR-HPV testing for screening of women younger than 30, which not only accelerates the diagnosis of cervical cancer but leads to a similar relative increase in CIN2/3 diagnosis to that found in women aged 30 to 49.

Early Welsh cervical screening programme learning as a consequence of the coronavirus pandemic

BACKGROUND

The coronavirus pandemic has had a profound impact on the cervical screening programme in Wales for the eligible women, sample takers and laboratory and colposcopy services.

AIMS

To explore what changes due the pandemic have adversely affected screening outcomes in Wales and what lessons can be learned to improve cervical screening in Wales and elsewhere.

METHODS

A review of the screening performance in 2020 and the first quarter of 2021 in Wales as well as a comparison with other cervical screening programme responses to the pandemic.

RESULTS

A three-month pause of screening together with a change in a variety of working practices, including social distancing, use of personal protective equipment, use of virtual meetings and home working have been implemented. The combination of a pause to the issue of invitations, plus reduced services in primary and secondary care, together with population lockdown, have contributed to longer waiting times for colposcopy and potentially delayed cancer diagnoses. Some programme changes which were being evaluated prior to the pandemic could be developed now to mitigate the impact of the pandemic such as improved information, increased screening intervals for human papillomavirus-based screening programmes and home working for call and recall staff.

CONCLUSIONS

Despite a considerable short-term interruption to the cervical screening programme, some changes introduced as a result of the coronavirus pandemic could provide key lessons learnt for improvement for cervical cancer prevention services.

Are We Facing a New Colposcopic Practice in the HPV Vaccination Era? Opportunities, Challenges, and New Perspectives

The combination of primary and secondary prevention has already influenced the colposcopic practice by reduction in HPV (human papillomavirus) vaccine-type HSIL (HIGH-GRADE SIL), colposcopy referral numbers, colposcopic positive predictive value (PPV) for CIN2+, and by modification of referral pattern, colposcopic performance, and procedures. Different strategies, both isolated and combined, have been proposed in order to maintain the diagnostic accuracy of colposcopy: patient risk stratification based on immediate or future risk of CIN3+ or on HPV genotyping after a positive screening test. Data are needed to support alternative colposcopic strategies based on vaccination status and on the application of artificial intelligence where the patient’s risk stratification is implicit in precision medicine which involves the transition from an operator-dependent morphology-based to a less-operator dependent, more biomolecular management. The patient’s risk stratification based on any combination of “history” and “test results” to decrease colposcopy workload further reduce colposcopic and histologic morphological approaches, while adding genotyping to the risk stratification paradigm means less cytologic morphologic diagnosis. In Italy, there is a strong colposcopic tradition and there is currently no immediate need to reduce the number of colposcopies. Instead, there is a need for more accredited colposcopists to maintain the diagnostic accuracy of colposcopy in the vaccination era.

Trend of HPV 16/18 Genotypes in Cervical Intraepithelial Neoplasia Grade 3: Data for 2007-2018

Aim

In the post-vaccination era, the starting age and time intervals of cervical screening could change (older age and longer screening intervals). This scenario may be achieved by significantly reducing human papillomavirus (HPV) 16/18 prevalence (genotypes included in the current vaccines). In this regard, assessing the trend over time of these HPV infections in high-grade cervical lesions can provide information on the objective. The present study aimed to evaluate the trend of HPV 16/18 over the years 2007–2018 in women with cervical intraepithelial neoplasia (CIN) grade 3.

Methods

This is a retrospective multi-institutional study including HPV genotyped and unvaccinated women under 30 with CIN3. The sample was divided into the following periods: 2007–2010, 2011–2014, 2015–2018. HPV genotypes were grouped in genotypes 16/18, genotypes 31/33/35/52/58/67 (genetically related to HPV16), genotypes 39/45/59/68/70 (genetically related to HPV18), genotypes 31/33/45/52/58 (high-risk types included in the nonavalent vaccine), possibly carcinogenic HPV (genotypes 26/30/53/67/70/73/82/85), low-risk HPV (genotypes 6/11/40/42/43/44/54/55/61). The trend between periods and HPV genotypes was measured using the Cochran–Armitage test for trend.

Results

The final analysis included 474 participants. HPV 16/18 prevalence decreased significantly over the years (77.8% vs 68.9% vs 66.0%, respectively, Ptrend=0.027). Possibly carcinogenic HPV (genotypes 26/30/53/67/70/73/82/85) showed a significant negative prevalence trend over time (4.9% vs 1.1% vs 1.3%, respectively, Ptrend=0.046). Finally, there was a significant positive trend over the years for high-risk HPV genotypes 31/33/45/52/58 in women under 25 (9.9% vs 17.0% vs 24.0%, respectively, Ptrend=0.048).

Conclusion

The prevalence of CIN3 lesions related to HPV 16/18 genotypes decreased over time from 2007 to 2018. These data highlight a herd effect of the HPV vaccine. However, fifteen years after HPV vaccine introduction, we are still a long way from herd immunity. The increase in high-risk types 31/33/45/52/58 will need to be reassessed when the nonavalent vaccine impact will be more reliable.

Physiopathology and effectiveness of therapeutic vaccines against human papillomavirus

Human papillomavirus (HPV) is a well-known sexually transmitted disorder globally. Human papillomavirus (HPV) is the 3rd most common cancer that causes cervical carcinoma, and globally it accounts for 275,000 deaths every year. The load of HPV-associated abrasions can be lessened through vaccination. At present, three forms of prophylactic vaccines, Cervarix, Gadrasil, and Gardasil 9, are commercially accessible but all these prophylactic vaccines have not the ability to manage and control developed abrasions or infections. Therefore, a considerable amount of the population is not secured from HPV infectivity. Consequently, the development of therapeutic HPV vaccines is a crucial requirement of this era, for the treatment of persisting infections, and to stop the progression of HPV-associated cancers. Therapeutic vaccines are a developing trial approach. Because of the constitutive expression of E6 and E7 early genes in cancerous and pre-cancerous tissues, and their involvement in disturbance of the cell cycle, these are best targets for this therapeutic vaccine treatment. For the synthesis and development of therapeutic vaccines, various approaches have been examined comprising cell-based vaccines, peptide/protein-based vaccines, nucleic acid-based vaccines, and live-vector vaccines all proceeding towards clinical trials. This review emphasizes the development, progress, current status, and future perspective of several vaccines for the cure of HPV-related abrasions and cancers. This review also provides an insight to assess the effectiveness, safety, efficacy, and immunogenicity of therapeutic vaccines in the cure of patients infected with HPV-associated cervical cancer.

Eliminating Cervical Cancer: Progress and Challenges for High-income Countries

In 2020, the World Health Organization launched a major initiative to eliminate cervical cancer globally. The initiative is built around the three key pillars of human papillomavirus (HPV) vaccination, cervical screening and treatment, with associated intervention targets for the year 2030. The '90-70-90' targets specify that 90% of adolescent girls receive prophylactic HPV vaccination, 70% of adult women receive a minimum twice-in-a-lifetime cervical HPV test and 90% receive appropriate treatment for preinvasive or invasive disease. Modelling has shown that if these targets are met, the elimination of cervical cancer, defined as fewer than four cases per 100 000 women per annum, will be achieved within a century. Many high-income countries are well positioned to eliminate cervical cancer within the coming decades, but few have achieved '90-70-90' and many challenges must still be addressed to deliver these critical interventions effectively. This review considers the current status of cervical cancer control in relation to each of the three elimination pillars in high-income countries and discusses some of the developments that will assist countries in reaching these ambitious targets by 2030.

Impact of screening between the ages of 60 and 64 on cumulative rates of cervical cancer to age 84y by screening history at ages 50 to 59: A population-based case-control study

There is little empirical data on the absolute benefit of cervical screening between ages 60-64y on subsequent cancer risk. We estimate the incidence of cervical cancer up to age 84y in women with and without a cervical cytology test at age 60-64y, by screening histories aged 50-59y. The current study is a population based case-control study of women born between 1928 and 1956 and aged 60-84y between 2007 and 2018. We included all such women diagnosed with cervical cancer in England and an aged-matched random sample without cancer. Women with a hysterectomy were excluded. Exposure was cervical cytology between ages 50-64y. The main outcome was 25y cumulative risk of cervical cancer between ages 60-84y. We found that eight in every 1000 (8.40, 95%CI: 7.78 to 9.07) women without a screening test between age 50-64y develop cervical cancer between the ages of 60-84y. The risk is half: 3.46 per 1000 (95%CI: 2.75 to 4.36) among women with a test between age 60-64y but no cervical screening test at age 50-59y. The absolute difference in risk is equivalent to one fewer cancer for every 202 such women screened. The highest risk (10.01, 95%CI:6.70 to 14.95) was among women with abnormal screening at ages 50-59y and no tests 60-64y. 25y risk among women with a screening test every five years between age 50-64y was just under two in a 1000 (1.59, 95%CI:1.42 to 1.78). Results suggest the upper age of screening should be dependent on previous screening participation and results.

Recovery strategies following COVID-19 disruption to cervical cancer screening and their impact on excess diagnoses

BACKGROUND

The COVID-19 pandemic has disrupted cervical cancer screening services. Assuming increases to screening capacity are unrealistic, we propose two recovery strategies: one extends the screening interval by 6 months for all and the other extends the interval by 36/60 months, but only for women who have already missed being screened.

METHODS

Using routine statistics from England we estimate the number of women affected by delays to screening. We used published research to estimate the proportion of screening age women with high-grade cervical intraepithelial neoplasia and progression rates to cancer. Under two recovery scenarios, we estimate the impact of COVID-19 on cervical cancer over one screening cycle (3 years at ages 25-49 and 5 years at ages 50-64 years). The duration of disruption in both scenarios is 6 months. In the first scenario, 10.7 million women have their screening interval extended by 6 months. In the second, 1.5 million women (those due to be screened during the disruption) miss one screening cycle, but most women have no delay.

RESULTS

Both scenarios result in similar numbers of excess cervical cancers: 630 vs. 632 (both 4.3 per 100,000 women in the population). However, the scenario in which some women miss one screening cycle creates inequalities-they would have much higher rates of excess cancer: 41.5 per 100,000 delayed for screened women compared to those with a 6-month delay (5.9 per 100,000).

CONCLUSION

To ensure equity for those affected by COVID-19 related screening delays additional screening capacity will need to be paired with prioritising the screening of overdue women.

Age-related distribution of uncommon HPV genotypes in cervical intraepithelial neoplasia grade 3

AIM

Cervical cancer prevention guidelines include Human Papillomavirus (HPV) test, cytology, and HPV-16/18 typing for triage to determine the risk of cervical intraepithelial neoplasia (CIN) grade 3 as the best proxy of cervical cancer risk. In doing that, they do not consider how age can modify the type-specific risk of CIN3. The present study aimed to evaluate the age-related distribution of HPV genotypes affecting the risk-assessment in cervical cancer screening programs: non-screening-type-HPV and non-HPV-16/18 in unvaccinated women with CIN3.

METHODS

Retrospective multi-institutional study, including HPV genotyped women with CIN3 on cone histology treated between 2014 and 2019. The sample was divided into three categories of age: <30, 30-44, ≥45. HPV genotypes were grouped in non-screening-type-HPV (not-including genotypes 16/18/31/33/35/39/45/51/52/56/58/59/66/68) and non-HPV-16/18. Associations and trends between different age-groups and HPV genotypes were measured.

RESULTS

1332 women were analyzed. Non-screening-type-HPV CIN3 were 73 (5.5%). Non-HPV-16/18 were found in 417 participants (31.3%). Women over 45 associated with non-screening-type HPV [odds ratio (OR) = 1.87, 95% confidence interval (CI) 1.07-3.25; p = 0.027]. Non-screening-type-HPV prevalence increased significantly with age (3.9% vs 5.1% vs 9.0%, p = 0.016). Women under 30 showed a lower rate of non-HPV-16/18 (OR = 0.65, 95% CI 0.47-0.89; p = 0.007). There was a positive trend with age of non-HPV-16/18 CIN3 (23.6% vs 32.1% vs 38.0%, p = 0.0004).

CONCLUSION

The proportion of CIN3 lesions unrelated to genotypes detected by primary screening tests increased with age. This implies that age probably modifies the risk of CIN3 and possibly of cancer associated with HPV types. The risk-based recommendation should take into consideration age to define the management of HPV positive women.

Cervical screening in high-income countries: the need for quality assurance, adjunct biomarkers and rational adaptation to HPV vaccination

We here discuss human papillomavirus (HPV)-based screening avenues to achieve elimination of cervical cancer as a public health problem in high-income country (HIC) settings, covering both the most recent data on the performance of HPV testing, as well as the currently most robust triage methods that are known. We also provide an outlook to several other promising, yet not fully established, options for triage that have been proposed, including methylation, dual staining, machine learning, and artificial intelligence. Finally, we discuss the key issue of how to adapt screening in the presence of programmatic HPV vaccination, and how this combination can best be leveraged for comprehensive cancer control. We conclude that, for the HIC setting, evidence-based and effective cervical screening methods are readily available, but whichever method or platform is chosen, we would propose that recurring audits of performance and population attendance remain common denominators for maintaining successful disease prevention.

Screening for the prevention and early detection of cervical cancer: protocol for systematic reviews to inform Canadian recommendations

PURPOSE

To inform recommendations by the Canadian Task Force on Preventive Health Care on screening in primary care for the prevention and early detection of cervical cancer by systematically reviewing evidence of (a) effectiveness; (b) test accuracy; (c) individuals' values and preferences; and (d) strategies aimed at improving screening rates.

METHODS

De novo reviews will be conducted to evaluate effectiveness and to assess values and preferences. For test accuracy and strategies to improve screening rates, we will integrate studies from existing systematic reviews with search updates to the present. Two Cochrane reviews will provide evidence of adverse pregnancy outcomes from the conservative management of cervical intraepithelial neoplasia. We will search Medline, Embase, and Cochrane Central (except for individuals' values and preferences, where Medline, Scopus, and EconLit will be searched) via peer-reviewed search strategies and the reference lists of included studies and reviews. We will search ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. Two reviewers will screen potentially eligible studies and agree on those to include. Data will be extracted by one reviewer with verification by another. Two reviewers will independently assess risk of bias and reach consensus. Where possible and suitable, we will pool studies via meta-analysis. We will compare accuracy data per outcome and per comparison using the Rutter and Gatsonis hierarchical summary receiver operating characteristic model and report relative sensitivities and specificities. Findings on values and preferences will be synthesized using a narrative synthesis approach and thematic analysis, depending on study designs. Two reviewers will appraise the certainty of evidence for all outcomes using GRADE (Grading of Recommendations Assessment, Development and Evaluation) and come to consensus.

DISCUSSION

The publication of guidance on screening in primary care for the prevention and early detection of cervical cancer by the Task Force in 2013 focused on cytology. Since 2013, new studies using human papillomavirus tests for cervical screening have been published that will improve our understanding of screening in primary care settings. This review will inform updated recommendations based on currently available studies and address key evidence gaps noted in our previous review.

The optimal HPV-screening protocol in Eastern-Europe: The example of Slovenia

OBJECTIVE

Eastern European countries are contemplating to introduce the high-risk Human Papillomavirus (HPV)-test as the primary screening test for their cervical cancer screening programme, but its optimal protocol is yet unknown. The aim of this study was to compare the costs, effects and cost-effectiveness of different primary HPV-screening protocols in Eastern Europe, using Slovenia as an example and with respect of local preferences for screening.

METHODS

We evaluated 968 HPV-screening protocols, which varied by screening ages, triage tests (i.e. cytology, repeat HPV and/or genotyping) and strategy for women under 35 years old, using the microsimulation model MISCAN-Cervix.

RESULTS

Within the subset of strategies that would be acceptable for Slovenian women, the optimal HPV-screening protocol is to start with two cytology tests at age 25 and 28 and switch to 5-yearly HPV screening from age 30 to 65. When also other protocols were considered, the optimal screening strategy would be 5-yearly HPV screening from age 30 to 65 only, improving the cost-effectiveness with 5%. Adding genotyping in the triage algorithm consistently improved cost-effectiveness. Sensitivity analyses showed the robustness of the results for other situations in Eastern Europe.

CONCLUSIONS

Despite differences in cervical cancer epidemiology between Eastern and Western European regions where HPV screening was evaluated, the optimal screening protocol was found to be very similar. Furthermore, strategies that were considered socially acceptable to the population were found to be almost as cost-effective as less acceptable strategies and can therefore be considered a viable alternative to prevent opportunistic screening.

Human papillomavirus genotype-specific risks for cervical intraepithelial lesions

Prevalence of different HPV genotypes is changing after HPV vaccination. The associated risks are needed for optimizing cervical cancer screening.To estimate HPV type-specific prevalence, odds ratio (OR), and positive predictive value (PPV) for cervical cytological abnormalities, we determined 41 different HPV genotypes in cervical samples from a population-based sample of 8351 women aged 18-51 years before HPV vaccination era (V501-033; NCT01077856).Prevalence of HPV16 was 4.9% (95% CI: 4.4-5.5) with the PPV for high-grade cytology 11.2%, and OR 11.9 (95% CI: 8.5-16.5). Carcinogenic HPVs included in the nonavalent vaccine (HPV16,18,31,33,45,52,58) had a population prevalence of 14.4% (95% CI: 13.5-15.4), with PPV of 8.0% (95% CI: 6.8-9.3) and OR 23.7 (95% CI: 16.0-63.5) for high-grade cytology. HPV types currently included in most screening tests, but not vaccinated against (HPV35,39,51,56,59,66,68) had a joint prevalence of 8.5% (95% CI: 7.8-9.2) with PPV of 4.4% (95% CI: 3.3-5.7) and OR of 2.9 (95% CI: 2.0-4.0) for high-grade cytology. The other 27 non-carcinogenic genotypes had a prevalence of 11.8%, PPV of 2.9% (95% CI:2.1-3.9), and OR 1.5 (95% CI: 1.1-2.2.) for high-grade cytology.These results suggest that HPV screening tests in the post-vaccination era might perform better if restricted to the HPV types in the nonavalent vaccine and screening for all 14 HPV types might result in suboptimal balance of harms and benefits.

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.

Defining benchmarks for tolerable risk thresholds in cancer screening: Impact of HPV vaccination on the future of cervical cancer screening

The performance of cervical cancer screening will decline as a function of lower disease prevalence—a consequence of successful human papillomavirus (HPV) vaccination. Replacement of cytology with molecular HPV testing as the primary screening test and adoption of risk‐based screening, with less intense screening of vaccinated individuals and initiated at older ages is expected to improve efficiency. However, policy officials may decide to further reduce or eliminate screening as the ratio of benefits to harms continues to decline. To evaluate the level of risk currently tolerated for different cancers in the United States (ie, for which clinical guidelines do not recommend secondary prevention though effective screening methods exist), we used US cancer registry data to compare incidence (2008‐2012) and survival (1988‐2011) associated with different cancers for which organized screening is recommended and not recommended. The most common cancer at ages 70 to 74 years (ie, age group with highest cancer incidence and reasonable life expectancy to consider screening in the US) satisfying Wilson and Jungner's classic screening criteria was vulvar cancer (incidence = 9/100 000 females). In comparison, the incidence of cervical cancer among females 65 years of age (the upper recommended age limit for screening) was 13 cases per 100 000 females (low as a reflection of effective screening), whereas 10‐year survival was 66% (similar to vulvar cancer at 67%). Our approach of defining tolerable risk in cancer screening could help guide future decisions to modify cervical screening programs.

Comparison of the implementation of human papillomavirus and hepatitis B vaccination programs in the United States: Implications for future vaccines

Vaccines for two viruses which cause cancer, human papillomavirus (HPV) and hepatitis B virus (HBV), are recommended for all children in the United States. Numerous parallels exist between the two vaccines in addition to their roles in cancer prevention, including transmission through sexual contact, multiple doses needed for series completion, and vaccine administration in adolescence for HPV and in the initial phase of the HBV vaccination program. All of these factors were viewed as potential barriers to achieving high rates of coverage, yet the ultimate success of the HBV vaccination program led to predictions that similarly high rates of coverage could be achieved for the HPV vaccine. However, currently, only the recommendation for HBV vaccination is supported by mandates for school entry in most states. Uptake of the HPV vaccine has lagged far behind U.S. goals for public health promotion. The aim of this paper is to examine factors which may account for the divergent pathways of the two vaccines. Four main factors are identified: logistical challenges of vaccine administration, attitudes of parents and healthcare providers, safety concerns, and cost. For each factor examined, recommendations are offered to confront similar barriers likely to arise for future vaccines. The authors conclude that gender-neutral state mandates coupled with school-located vaccination programs, stronger gender-neutral messaging from pharmaceutical companies and healthcare providers, and younger age of vaccine administration, if approved, present the most promising approaches to improving uptake of the HPV vaccine, and similar vaccines down the road.

Different types of adjuvants in prophylactic and therapeutic human papillomavirus vaccines in laboratory animals: a systematic review

Human papillomavirus (HPV) causes cervical carcinoma, which and is the third most common cancer, accounting for 275,000 deaths annually worldwide. Adjuvants have a key role in promotion of vaccine efficacy; therefore, using prophylactic and therapeutic vaccines combined with adjuvant could be of great benefit in prevention and treatment of cervical cancer. There are different types of adjuvants, including MF59^TM adjuvants, RNA-based, JY (interleukin2/chitosan), cholera toxin (CT), heat-labile enterotoxin (LT), Freund's adjuvant, alum, SA-4-1BBL, λ-carrageenan (λ-CGN), heat shock proteins (HSPs), juzen-taiho-to (JTT) and hochu-ekki-to (HET), ISCOM and ISCOMATRIX™, very small size proteoliposomes (VSSPs), granulocyte macrophage colony-stimulating factor (GM-CSF), and Toll-like receptors (TLRs). Adjuvants have various functions, especially in therapeutic vaccines, and they lead to an increase in cytotoxic T lymphocytes (CTLs), so they are important in the design of vaccines. Here, we review the currently used adjuvants and their combinations with HPV protein vaccines in order to introduce an appropriate adjuvant for HPV vaccines.

Age-Related Changes in the Fraction of Cervical Intraepithelial Neoplasia Grade 3 Related to HPV Genotypes Included in the Nonavalent Vaccine

Objective

The prevalence of some human papillomavirus (HPV) genotypes has been shown to change with age. So, also the distribution of HPV genotypes included in the nonavalent vaccine may not be the same at all ages, and this could mean that vaccine protection against cervical cancer may be affected by age. The present study aimed to evaluate whether there are age-related changes in the fraction of high-grade cervical intraepithelial neoplasia (CIN) attributable to HPV genotypes included in the nonavalent vaccine.

Methods

Two hundred four consecutive women undergoing conization with a histological diagnosis of CIN3 were retrospectively analyzed. All included women had a preconization HPV genotyping (HPV Sign® Genotyping Test). The women were divided into three groups according to age: <35, 35–44, and ≥45 years of age. Based on HPV genotypes detected in cervical lesions, the age-related changes in the expected vaccine protection were evaluated by the Cochran–Armitage test for trend.

Results

The fraction of CIN3 attributable to HPV genotypes included in the nonavalent vaccine showed a significant negative trend with increasing age, with potential vaccine protection of 82% after the age of 45 (p=0.006). The rate of HPV-16 and HPV-33, included in the vaccine, showed a negative trend with age (p=0.047 and p=0.044, respectively). Among HPV genotypes not covered by the vaccine, the rate of non-high-risk HPVs (genotypes: 53-54-70-73-82-85-87) showed a significant positive trend with increasing age (p=0.018).

Conclusions

Although the fraction of CIN3 attributable to genotypes included in the nonavalent HPV vaccine was high even after age 45, older women appeared to be more at risk of high-grade CIN related to HPV genotypes not included in the vaccine. Interestingly, older women showed a higher rate of precancerous cervical lesions associated with non-high-risk HPV. The present findings seem to raise the question about the management of cervical pathology at a later age in a future postvaccination era.

Assessing the cost-effectiveness of HPV vaccination strategies for adolescent girls and boys in the UK

BACKGROUND

Human papillomavirus (HPV) is the most widespread sexually transmitted infection worldwide. It causes several health consequences, in particular accounting for the majority of cervical cancer cases in women. In the United Kingdom, a vaccination campaign targeting 12-year-old girls started in 2008; this campaign has been successful, with high uptake and reduced HPV prevalence observed in vaccinated cohorts. Recently, attention has focused on vaccinating both sexes, due to HPV-related diseases in males (particularly for high-risk men who have sex with men) and an equity argument over equalising levels of protection.

METHODS

We constructed an epidemiological model for HPV transmission in the UK, accounting for nine of the most common HPV strains. We complemented this with an economic model to determine the likely health outcomes (healthcare costs and quality-adjusted life years) for individuals from the epidemiological model. We then tested vaccination with the three HPV vaccines currently available, vaccinating either girls alone or both sexes. For each strategy we calculated the threshold price per vaccine dose, i.e. the maximum amount paid for the added health benefits of vaccination to be worth the cost of each vaccine dose. We calculated results at 3.5% discounting, and also 1.5%, to consider the long-term health effects of HPV infection.

RESULTS

At 3.5% discounting, continuing to vaccinate girls remains highly cost-effective compared to halting vaccination, with threshold dose prices of £56-£108. Vaccination of girls and boys is less cost-effective (£25-£53). Compared to vaccinating girls only, adding boys to the programme is not cost-effective, with negative threshold prices (-£6 to -£3) due to the costs of administration. All threshold prices increase when using 1.5% discounting, and adding boys becomes cost-effective (£36-£47). These results are contingent on the UK's high vaccine uptake; for lower uptake rates, adding boys (at the same uptake rate) becomes more cost effective.

CONCLUSIONS

Vaccinating girls is extremely cost-effective compared with no vaccination, vaccinating both sexes is less so. Adding boys to an already successful girls-only programme has a low cost-effectiveness, as males have high protection through herd immunity. If future health effects are weighted more heavily, threshold prices increase and vaccination becomes cost-effective.

Optimising future cervical screening strategies

The switch from primary cytology to primary high risk papillomavirus (HR-HPV) testing for cervical screening is now being implemented in a number of countries. The advantages of this are to increase screening sensitivity which will save lives, and at the same time to extend screening intervals. The challenge with HR-HPV testing is its relatively poor specificity which means identifying a large number of women who are HR-HPV positive with negative cytology. One way of tackling this is to use early recall, in order to select referral to colposcopy to those women who do not clear the virus over a period of 1-2 years, as done in the recently published English Pilot Study. Another challenge in optimising screening is to recognise that wide coverage with prophylactic vaccination will require fewer screens over the lifetime of vaccinated women to maintain cost-effectiveness. HR-HPV testing allows self sampling which could both encourage more women to be screened and be more convenient for those who do wish to be screened. Cervical cancer prevention which combines vaccination and screening now offers a future in which cervical cancer could become a rarity, but efficient strategies need to be implemented.

Human Papillomavirus Research: Where Should We Place Our Bets?

BACKGROUND

Massive strides have been made with respect to primary and secondary prevention of human papillomavirus (HPV)-associated disease as a result of prophylactic vaccination and cervical screening based on molecular HPV testing. However, cervical cancer continues to be an important clinical and societal burden. Additionally, other HPV-associated cancers, for which there are no screening programmes, are rising. Finally, the optimal combination of vaccination and screening strategies will require careful thinking. Considering this unprecedented and important time, we were keen to solicit the views of the expert community to determine what they perceived were the key priorities for HPV research. Our objective was to identify consensus and key priorities for HPV-based research through provision of a questionnaire disseminated to a multidisciplinary group of key opinion leaders (KOLs).

SUMMARY

A structured survey composed of 46 HPV research "categories" was sent to 73 KOLs who were invited to "rank" the categories according to priority. The invitees represented clinical and public health disciplines as well as basic scientists. Scores were weighted according to the number of responses. Invitees also had the opportunity to comment on barriers to the research and suggest other research areas that required attention not reflected in the survey. We received 29 responses in total; overall, the 3 highest-ranked categories were "optimal cervical screening in low and middle-income countries (LMICs)," "primary disease prevention in LMICs" and "impact of vaccine on HPV infection and associated disease." "HPV and the microbiome" and "mechanisms of transformation" were the highest-ranked categories with respect to basic research. Consistent barriers to research were around governance on the use of samples and data and funding, particularly in an era of vaccination. Key Messages: Research to support the management of disease in LMICs is clearly perceived as a priority in the international community in addition to other diverse areas which necessitate an improved basic understanding of viral mechanisms and interactions. International, multidisciplinary efforts which articulate the broader HPV research agenda will be important when seeking funding in addition to international endeavours to support the efficient use of existing samples and cohorts to facilitate such research.

Impact of screening on cervical cancer incidence in England: a time trend analysis

OBJECTIVES

To better model underlying trends in cervical cancer incidence so as to model past trends, to estimate the impact of cervical screening on cervical cancer rates at different ages and to obtain a counterfactual baseline under a no-screening scenario.

DESIGN

Trend analysis of cancer registry data recorded between 1971 and 2013.

SETTING

England.

PARTICIPANTS

132 493 women aged 20-84 with a diagnosis of cervical cancer.

OUTCOME MEASURE

Cervical cancer incidence data were modelled using a modified age period cohort model able to capture both increased exposure to human papillomavirus (HPV) as well as changes in the age of exposure to HPV in young cohorts. Observed rates were compared with counterfactual baseline rates under a no-screening scenario to estimate the protective effect of screening.

RESULTS

Rates of cervical cancer incidence have been decreasing since the introduction of screening but are projected to increase in the future under the current scenario. Between 1988 and 2013, it was estimated that screening had prevented approximately 65 000 cancers. Moreover, in 2013, the age-standardised rate (ASR) estimated under the no-screening scenario (37.9, 95% CI 37.4 to 38.3) was threefold higher among women aged 20-84 than the observed ASR (12.8, 95% CI 12.3 to 13.3). We estimate that the age of first HPV exposure has decreased by about 1 year every decade since the early 1970s (women born in 1955 onwards).

CONCLUSIONS

Our results corroborated the importance of screening in preventing cervical cancer and indicated future rates are dependent on age at HPV exposure. Estimated future rates can be used for healthcare planning while the counterfactual baseline to quantify the impact of HPV vaccination in microsimulations.

Adapting cervical cancer screening for women vaccinated against human papillomavirus infections: The value of stratifying guidelines

BACKGROUND

Several countries have implemented vaccination against human papillomavirus (HPV) for adolescent girls and must decide whether and how to adapt cervical cancer (CC) screening for these low-risk women. We aimed to identify the optimal screening strategies for women vaccinated against HPV infections and quantify the amount that could be spent to identify vaccination status among women and stratify CC screening guidelines accordingly.

METHODS

We used a mathematical model reflecting HPV-induced CC in Norway to project the long-term health benefits, resources and costs associated with 74 candidate-screening strategies that varied by screening test, start age and frequency. Strategies were considered separately for women vaccinated with the bivalent/quadrivalent (2/4vHPV) and nonavalent (9vHPV) vaccines. We used a cost-effectiveness framework (i.e. incremental cost-effectiveness ratios and net monetary benefit) and a commonly-cited Norwegian willingness-to-pay threshold of €75,000 per quality-adjusted life-year gained.

RESULTS

The most cost-effective screening strategy for 9vHPV- and 2/4vHPV-vaccinated women involved HPV testing once and twice per lifetime, respectively. The value of stratifying guidelines by vaccination status was €599 (2/4vHPV) and €725 (9vHPV) per vaccinated woman. Consequently, for the first birth cohort of ∼22,000 women who were vaccinated in adolescence in Norway, between €10.5-13.2 million over their lifetime could be spent on identifying individual vaccination status and stratify screening while remaining cost-effective.

CONCLUSION

Less intensive strategies are required for CC screening to remain cost-effective in HPV-vaccinated women. Moreover, screening can remain cost-effective even if large investments are made to identify individual vaccination status and stratify screening guidelines accordingly.

Prediction of cervical cancer incidence in England, UK, up to 2040, under four scenarios: a modelling study

BACKGROUND

In the next 25 years, the epidemiology of cervical cancer in England, UK, will change: human papillomavirus (HPV) screening will be the primary test for cervical cancer. Additionally, the proportion of women screened regularly is decreasing and women who received the HPV vaccine are due to attend screening for the first time. Therefore, we aimed to estimate how vaccination against HPV, changes to the screening test, and falling screening coverage will affect cervical cancer incidence in England up to 2040.

METHODS

We did a data modelling study that combined results from population modelling of incidence trends, observable data from the individual level with use of a generalised linear model, and microsimulation of unobservable disease states. We estimated age-specific absolute risks of cervical cancer in the absence of screening (derived from individual level data). We used an age period cohort model to estimate birth cohort effects. We multiplied the absolute risks by the age cohort effects to provide absolute risks of cervical cancer for unscreened women in different birth cohorts. We obtained relative risks (RRs) of cervical cancer by screening history (never screened, regularly screened, or lapsed attender) using data from a population-based case-control study for unvaccinated women, and using a microsimulation model for vaccinated women. RRs of primary HPV screening were relative to cytology. We used the proportion of women in each 5-year age group (25-29 years to 75-79 years) and 5-year period (2016-20 to 2036-40) who have a combination of screening and vaccination history, and weighted to estimate the population incidence. The primary outcome was the number of cases and rates per 100 000 women under four scenarios: no changes to current screening coverage or vaccine uptake and HPV primary testing from 2019 (status quo), changing the year in which HPV primary testing is introduced, introduction of the nine-valent vaccine, and changes to cervical screening coverage.

FINDINGS

The status quo scenario estimated that the peak age of cancer diagnosis will shift from the ages of 25-29 years in 2011-15 to 55-59 years in 2036-40. Unvaccinated women born between 1975 and 1990 were predicted to have a relatively high risk of cervical cancer throughout their lives. Introduction of primary HPV screening from 2019 could reduce age-standardised rates of cervical cancer at ages 25-64 years by 19%, from 15·1 in 2016 to 12·2 per 100 000 women as soon as 2028. Vaccination against HPV types 16 and 18 (HPV 16/18) could see cervical cancer rates in women aged 25-29 years decrease by 55% (from 20·9 in 2011-15 to 9·5 per 100 000 women by 2036-40), and introduction of nine-valent vaccination from 2019 compared with continuing vaccination against HPV 16/18 will reduce rates by a further 36% (from 9·5 to 6·1 per 100 000 women) by 2036-40. Women born before 1991 will not benefit directly from vaccination; therefore, despite vaccination and primary HPV screening with current screening coverage, European age-standardised rates of cervical cancer at ages 25-79 years will decrease by only 10% (from 12·8 in 2011-15 to 11·5 per 100 000 women in 2036-40). If screening coverage fell to 50%, European age-standardised rates could increase by 27% (from 12·8 to 16·3 per 100 000 by 2036-40).

INTERPRETATION

Going forward, focus should be placed on scenarios that offer less intensive screening for vaccinated women and more on increasing coverage and incorporation of new technologies to enhance current cervical screening among unvaccinated women.

FUNDING

Jo's Cervical Cancer Trust and Cancer Research UK.

GENESIS - The GENEric SImulation System for Modelling State Transitions

This software implements a discrete time Markov chain model, used to model transitions between states when the transition probabilities are known a priori. It is highly configurable; the user supplies two text files, a "state transition table" and a "config file", to the Perl script genesis.pl. Given the content of these files, the script generates a set of C++ classes based on the State design pattern, and a main program, which can then be compiled and run. The C++ code generated is based on the specification in the text files. Both multiple branching and bi-directional transitions are allowed. The software has been used to model the natural histories of colorectal cancer in Mexico. Although written primarily to model such disease processes, it can be used in any process which depends on discrete states with known transition probabilities between those states. One suitable area may be in environmental modelling. A test suite is supplied with the distribution. Due to its high degree of configurability and flexibility, this software has good re-use potential. It is stored on the Figshare repository.