Whole tissue cervical mapping of HPV infection: Molecular evidence for focal latent HPV infection in humans

The human Papillomavirus twilight zone - Latency, immune control and subclinical infection

The incorporation of HPV DNA testing into cervical screening programs has shown that many HPV-positive women are cytologically normal, with HPV-positivity fluctuating throughout life. Such results suggest that papillomaviruses may persist in a latent state after disease clearance, with sporadic recurrence. It appears that virus latency represents a narrow slot in a wider spectrum of subclinical and possibly productive infections. Clinical studies, and animal model infection studies, suggested a key role for host immune surveillance in maintaining such asymptomatic infections, and although infections may also be cleared, most studies have used the term 'clearance' to describe a situation where the presence of HPV DNA falls below the clinical detection level. Given our knowledge of papillomavirus immune evasion strategies and the restricted pattern of viral gene expression required for 'basal cell' persistence, the term 'apparent clearance' and 'subclinical persistence' of infection may better summarise our understanding. Subclinical infection also encompasses the lag phase, which occurs between infection and lesion development. This is dependent on infection titre, with multifocal infections developing more rapidly to disease. These concepts can usefully influence patient management where HPV-positivity occurs sometime after the onset of sexual activity, and where vertical transmission is suspected despite a lag period.

Untreated cervical intraepithelial neoplasia grade 2 and subsequent risk of cervical cancer: population based cohort study

OBJECTIVE

To describe the long term risk of cervical cancer in women with untreated (that is, undergoing active surveillance) or immediately treated cervical intraepithelial neoplasia grade 2 (CIN2).

DESIGN

Nationwide population based historical cohort study.

SETTING

Danish healthcare registries.

PARTICIPANTS

Women with CIN2 diagnosed in 1998-2020 and aged 18-40 years at diagnosis, who had either active surveillance or immediate treatment with large loop excision of the transformation zone (LLETZ). Women with a previous record of CIN2 or worse or LLETZ were excluded.

MAIN OUTCOME MEASURE

A Weibull survival model for interval censored time-to-event data was used to estimate the cumulative risk of cervical cancer. Inverse probability treatment weighting was used to adjust estimates for age, index cytology, calendar year, and region of residence.

RESULTS

The cohort included 27 524 women with CIN2, of whom 12 483 (45%) had active surveillance and 15 041 (55%) had immediate LLETZ. During follow-up, 104 cases of cervical cancer were identified-56 (54%) in the active surveillance group and 48 (46%) in the LLETZ group. The cumulative risk of cervical cancer was comparable across the two groups during the active surveillance period of two years. Thereafter, the risk increased in the active surveillance group, reaching 2.65% (95% confidence interval 2.07% to 3.23%) after 20 years, whereas it remained stable in the LLETZ group at 0.76% (0.58% to 0.95%).

CONCLUSIONS

Undergoing active surveillance for CIN2, thereby leaving the lesion untreated, was associated with increased long term risk of cervical cancer compared with immediate LLETZ. These findings show the importance of continued follow-up of women having active surveillance.

Unveiling the Association between HPV and Pan-Cancers: A Bidirectional Two-Sample Mendelian Randomization Study

INTRODUCTION

More and more studies have focused on the associations between human papillomavirus (HPV) infection and pan-cancers. However, current evidence is largely based on retrospective studies, which are susceptible to confounding factors and do not enable the establishment of causal relationships.

METHODS

A bidirectional two-sample Mendelian randomization (MR) design was employed to thoroughly evaluate the causal relationships between HPV and 12 site-specific cancers except cervical cancer. Single nucleoside polymers (SNPs) with strong evidence from genome-wide association studies (GWAS) were selected from HPV exposure datasets and used as instrumental variables (IVs) in this study. For the MR analysis results, MR-Egger's intercept P test, MR-PRESSO global test, Cochran's Q test and a leave-one-out test were applied for sensitivity analysis. Using HPVTIMER, we also performed immune infiltration analyses in head and neck squamous cell carcinoma (HNSCC), oropharyngeal squamous cell carcinoma (OPSCC) and vulval squamous cell carcinoma (VSCC) to evaluate the tumor-immune microenvironment.

RESULTS

Based on the evidence of MR analysis, our study conclusively identified HPV16 as a risk factor implicated in the development of bladder cancer, colorectal cancer, and breast cancer, while HPV18 was identified as a risk factor for prostate cancer, ovarian cancer, lung cancer and breast cancer. The MR results also showed that HPV16 may be a protective factor for prostate cancer, anal cancer, lung cancer and oropharyngeal cancer, while HPV18 may be a protective factor for vaginal cancer.

CONCLUSION

An HPV infection may modulate the immune microenvironment and therefore has a potential inhibitory effect on the development of certain cancers. These conclusions provided new insights into the potential mechanisms of carcinogenesis and needed further research for validation.

Prophylactic HPV vaccines in patients with HPV-associated diseases and cancer

Individuals with human papillomavirus (HPV)-related disease remain at risk for subsequent HPV infection and related disease after treatment of specific lesions. Prophylactic HPV vaccines have shown benefits in preventing subsequent HPV-related disease when administered before or soon after treatment. Based on our understanding of the HPV life cycle and vaccine mechanism of action, prophylactic HPV vaccination is not expected to clear active persistent HPV infection or unresected HPV-associated dysplastic tissue remaining after surgery. However, vaccination may reasonably be expected to prevent new HPV infections caused by a different HPV type as well as re-infection with the same HPV type, whether from a new exposure to an infected partner or through autoinoculation from an adjacent or distant productively infected site. In this review, we describe the evidence for using prophylactic HPV vaccines in patients with HPV-associated disease before, during, or after treatment and discuss potential mechanisms by which individuals with HPV-associated disease may or may not benefit from prophylactic vaccines. We also consider how precise terminology relating to the use of prophylactic vaccines in this population is critical to avoid the incorrect implication that prophylactic vaccines have direct therapeutic potential, which would be counter to the vaccine's mechanism of action, as well as considered off-label. In other words, the observed effects occur through the known mechanism of action of prophylactic HPV vaccines, namely by preventing virus of the same or a different HPV type from infecting the patient after the procedure.

HPV Testing and its Role in Cervical Cancer Screening

The recognition that persistent infection with carcinogenic human papillomavirus (HPV) is a necessary cause of cervical precancer and cancer has led to the introduction of HPV testing into cervical cancer screening, either as a primary screening test or in conjunction with cervical cytology (i.e., co-testing). HPV testing has much higher sensitivity for detection of cervical precancer and provides greater long-term reassurance if negative compared to cytology. However, most HPV infections are transient, and do not progress to invasive cancer, thus triage tests are required to identify individuals who should be referred to colposcopy for diagnostic evaluation. This chapter begins with a description of the biology, natural history, and epidemiology of HPV as a foundation for understanding the role of HPV in cervical carcinogenesis. This section is followed by a detailed discussion regarding the introduction of HPV-based testing and triage into cervical cancer screening and management. Summarized triage tests include cervical cytology, HPV genotyping, p16/Ki-67 dual stain, and HPV and cellular methylation markers. The final section of this chapter includes an important discussion on cervical cancer disparities, particularly within the United States, followed by concluding remarks.

Cervical Health in Systemic Lupus Erythematosus

Objective

A health disparity exists for African American (AA) women with systemic lupus erythematosus (SLE) who have increased prevalence of human papilloma virus (HPV) infection and cervical neoplasia. We used a self-sampling brush to obtain cervical cells to assess cytology, HPV infection, and vaginal cytokine production in AA women with SLE.

Methods

Thirty AA women with SLE ages 18-50 years consented to participate. Clinical information was obtained by review of records and patient interviews, and surveys administered to assess cervical health history, knowledge of HPV, and satisfaction with the self-sampling brush. Vaginal samples were analyzed for cytology, HPV DNA and RNA, and vaginal cytokine RNA.

Results

Our cohort (mean 36.9, ±9.4 years) had moderate/severe SLE and were on immunosuppressives. The majority had history of abnormal pap smears (63%) with prevalent risk factors for HPV infection: multiple sex partners (9.5 ± 7), not vaccinated for HPV (83.3%), smoking (26.7%), and not using condoms (73.3%). Most were aware of HPV causing cervical cancer (70%) but were unaware of other HPV-related diseases. Most preferred self-sampling over traditional pap smear (80%). Abnormal cytology was detected in 13.3%. HPV DNA was detected in 70%, with half showing multiple types, and all showing active infection (+RNA). HPV-infected samples demonstrated RNA expression of multiple cytokines with no specific/ consistent pattern.

Conclusion

Our high-risk cohort lacked knowledge about HPV-related diseases and were not employing strategies to reduce their risk with vaccination and condoms. This study highlights the need for cervical health education, increased monitoring, and intervention in these high-risk women.

Older women testing positive for HPV16/18 on cervical screening and risk of high-grade cervical abnormality

In Australia's HPV-based cervical screening program, we previously showed that risk of histological high-grade abnormality at 1 year post screening decreased with age in women with oncogenic HPV. In this study, we followed 878 HPV16/18 positive women aged 55 years and over for up to 3 years post screening test, to determine the proportion with histological high-grade abnormality (HGA, incorporating high-grade squamous intraepithelial abnormality (HSIL), adenocarcinoma in situ (AIS), squamous cell carcinoma (SCC) and adenocarcinoma) and to correlate risk of HGA with liquid-based cytology result and with prior screening history. HGA was detected in 7.8% at 1 year and 10.0% at 3 years, with no significant difference (P = .136), despite the number of women with follow-up information significantly increasing from 82.9% to 91.0% (P < .0001). The proportion of HPV16/18 positive women with HGA at 3 years was highest in those with an HSIL cytology result (79.0%) and lowest in those with negative cytology (6.2%). Women with an adequate screening history had fewer HGA than such women with inadequate prior screening (6.6% vs 16.0%, P = .001) or with a history of an abnormality (6.6% vs 14.4%, P = .001). HPV16/18 infection in women over 55 years may have a different natural history from that in younger women, in whom HGA are more common after HPV16/18 detection. In HPV-based cervical screening programs, management algorithms for screen-detected abnormalities based on risk stratification should include factors such as age, screening history and index cytology result, so that women receive appropriate investigation and follow-up.

Different human papillomavirus types share early natural history transitions in immunocompetent women

Necessary stages of cervical carcinogenesis include acquisition of a carcinogenic human papillomavirus (HPV) type, persistence associated with the development of precancerous lesions, and invasion. Using prospective data from immunocompetent women in the Guanacaste HPV Natural History Study (NHS), the ASCUS-LSIL Triage Study (ALTS) and the Costa Rica HPV Vaccine Trial (CVT), we compared the early natural history of HPV types to inform transition probabilities for health decision models. We excluded women with evidence of high-grade cervical abnormalities at any point during follow-up and restricted the analysis to incident infections in all women and prevalent infections in young women (aged <30 years). We used survival approaches accounting for interval-censoring to estimate the time to clearance distribution for 20 529 HPV infections (64% were incident and 51% were carcinogenic). Time to clearance was similar across HPV types and risk classes (HPV16, HPV18/45, HPV31/33/35/52/58, HPV 39/51/56/59 and noncarcinogenic HPV types); and by age group (18-29, 30-44 and 45-54 years), among carcinogenic and noncarcinogenic infections. Similar time to clearance across HPV types suggests that relative prevalence can predict relative incidence. We confirmed that there was a uniform linear association between incident and prevalent infections for all HPV types within each study cohort. In the absence of progression to precancer, we observed similar time to clearance for incident infections across HPV types and risk classes. A singular clearance function for incident HPV infections has important implications for the refinement of microsimulation models used to evaluate the cost-effectiveness of novel prevention technologies.

Evidence of latent HPV infection in older Danish women with a previous history of cervical dysplasia

INTRODUCTION

Understanding whether human papillomavirus (HPV) may establish latency in the uterine cervix is important. A better understanding of HPV natural history is useful for clinical counseling of women attending screening and to accurately inform health prevention strategies such as screening and HPV vaccination. We evaluated the extent of latent HPV infections in older women with a history of abnormal cytology.

MATERIAL AND METHODS

We conducted a cross-sectional study in Aarhus, Denmark, from March 2013 through April 2015. Women were enrolled if they underwent cervical amputation or total hysterectomy because of benign disease. Prior to surgery, women completed a questionnaire and a cervical smear was collected for HPV testing and morphological assessment. For evaluation of latency (i.e., no evidence of active HPV infection, but HPV detected in the tissue), we selected women with a history of abnormal cervical cytology or histology, as these women were considered at increased risk of harboring a latent infection. Cervical tissue underwent extensive HPV testing using the SPF10-DEIA-LipA25 assay.

RESULTS

Of 103 women enrolled, 26 were included in this analysis. Median age was 55 years (interquartile range [IQR] 52-65), and most women were postmenopausal and parous. The median number of sexual partners over the lifetime was six (IQR 3-10), and 85% reported no recent new sexual partner. Five women (19.2%) had evidence of active infection at the time of surgery, and 19 underwent latency evaluation. Of these, a latent infection was detected in 11 (57.9%), with HPV16 being the most prevalent type (50%). Nearly 80% (n = 14) of the 18 women with a history of previous low-grade or high-grade cytology with no treatment had an active or latent HPV infection, with latent infections predominating. HPV was detected in two of the six women with a history of high-grade cytology and subsequent excisional treatment, both as latent infections.

CONCLUSIONS

HPV can be detected in cervical tissue specimens without any evidence of an active HPV infection, indicative of a latent, immunologically controlled infection. Modeling studies should consider including a latent state in their model when estimating the appropriate age to stop screening and when evaluating the impact of HPV vaccination.

Known Benefits and Unknown Risks of Active Surveillance of Cervical Intraepithelial Neoplasia Grade 2

Cervical intraepithelial neoplasia grade 2 (CIN 2) is an equivocal diagnosis with high interobserver variation. Owing to high regression rates of 50%, many countries recommend active surveillance of CIN 2, especially in women younger than age 25-30 years, where regression rates are even higher (ie, 60%). Additionally, excisional treatment is associated with increased risk of reproductive harm, particularly preterm birth. Active surveillance typically consists of semi-annual follow-up visits for up to 2 years, including colposcopy and either cytology, testing for human papillomavirus, or both. Excisional treatment is recommended for progression or persistent disease after 2 years. Because active surveillance in younger women is relatively new, knowledge on subsequent risk of cervical cancer is limited. Considering human papillomavirus latency, women undergoing active surveillance might be at higher risk of cervical cancer than women undergoing excisional treatment. Furthermore, there are limited data describing preferences of women for the management of CIN 2, and it is also unclear how active surveillance may affect planning for future pregnancy. In this context, biomarkers for risk stratification of CIN 2 into either high or low probability of progression would allow for targeted treatment. Currently, immunohistochemical staining for p16 is used to clarify the histologic diagnosis, but whether it or other biomarkers can be used for risk-stratification in clinical management of women with CIN 2 remains unknown. In conclusion, active surveillance of CIN 2 needs further investigation, including understanding the long-term cervical cancer risk and evaluation of markers that may enable risk stratification of CIN 2.

HPV and the Risk of HIV Acquisition in Women

The risk of HIV acquisition is low on a per-contact basis but increased by transmission co-factors such as other sexually transmitted infections (STIs). Human papillomavirus (HPV) is a prevalent STI that most individuals will acquire HPV in their lifetime. Current HPV vaccines can prevent newly acquired infections, but are largely ineffective against established HPV, complicating worldwide eradication efforts. In addition to being the causative agent of cervical cancer, accumulating evidence suggests that HPV infection and/or accompanying cervical inflammation increase the risk of HIV infection in men and women. The fact that immunological features observed during HPV infection overlap with cellular and molecular pathways known to enhance HIV susceptibility underscore the potential interplay between these two viral infections that fuel their mutual spread. Here we review current insights into how HPV infection and the generation of anti-HPV immunity contribute to higher HIV transmission rates, and the impact of HPV on mucosal inflammation, immune cell trafficking, and epithelial barrier function.

Human papillomaviruses: diversity, infection and host interactions

Human papillomaviruses (HPVs) are an ancient and highly successful group of viruses that have co-evolved with their host to replicate in specific anatomical niches of the stratified epithelia. They replicate persistently in dividing cells, hijack key host cellular processes to manipulate the cellular environment and escape immune detection, and produce virions in terminally differentiated cells that are shed from the host. Some HPVs cause benign, proliferative lesions on the skin and mucosa, and others are associated with the development of cancer. However, most HPVs cause infections that are asymptomatic and inapparent unless the immune system becomes compromised. To date, the genomes of almost 450 distinct HPV types have been isolated and sequenced. In this Review, I explore the diversity, evolution, infectious cycle, host interactions and disease association of HPVs.

Human papillomavirus genotypes and the risk factors associated with multicentric intraepithelial lesions of the lower genital tract: a retrospective study

BACKGROUND

Multicentric intraepithelial lesions of the lower genital tract (multicentric lesions) were defined as intraepithelial lesions of two or three sites within cervix, vagina, and vulva occurring synchronously or sequentially. The characteristics of multicentric lesions has been poorly understood. This study aimed to evaluate the risk factors for multicentric lesions, including specific HPV genotypes.

METHODS

A retrospective case-control study was performed involving patients histologically diagnosed with multicentric lesions between January 2018 and October 2019. Controls were patients histologically diagnosed with single cervical intraepithelial neoplasia (CIN) and admitted during the same period. Univariable and multivariable analyses were used to assess the risk factors for multicentric lesions.

RESULTS

Of 307 patients with multicentric lesions, the median age was 50 years (interquartile range: 43-55.5), and they were older than patients with single CIN (median age: 43 years, interquartile range: 36-50). In the multicentric lesion group, the proportions of cytologic abnormalities, HPV positivity, and multiple HPV infections were 68.9, 97.0, and 36.5%, respectively. In the multivariable analysis, menopause, a history of malignant tumors beyond the lower genital tract and multiple HPV infections were associated with the incidence of multicentric lesions (Odd ratio (OR) = 3.14, 95% confidence interval (CI) 2.24-4.41; OR = 9.58, 95% CI 1.02-89.84; OR = 1.47, 95% CI 1.03-2.10). The common HPV genotypes were HPV16, HPV53, HPV58, HPV52, HPV51, HPV56 and HPV18 in patients with multicentric lesions. The proportion of HPV16 infection was higher in high-grade lesions group than that in low-grade lesions group (OR = 2.54, 95% CI 1.34-4.83). The OR for multicentric lesions, adjusted for menopause, smoking, gravidity, parity, a history of malignant tumor beyond the lower genital tract and multiple HPV infection, was 1.97 (95% CI 1.04-3.75) in patients with HPV51 infection.

CONCLUSIONS

Multicentric lesions were associated with menopause, a history of malignant tumors and multiple HPV infections. HPV16 was the most common genotype, especially in high grade multicentric lesions and HPV51 infection was found to be a risk factor for detecting multicentric lesions.

Maternal human papillomavirus infections at mid-pregnancy and delivery in a Scandinavian mother-child cohort study

OBJECTIVES

Human papillomavirus (HPV) infections are common, especially during women's reproductive years, with unclear obstetrical impact. This study aimed to identify HPV prevalence at mid-gestation and delivery, type-specific persistence from mid-gestation to delivery, and risk factors for HPV infection and persistence.

METHODS

In 757 women from a Scandinavian prospective mother-child cohort, HPV was analyzed in first-void urine samples at mid-gestation and delivery. We used Seegene Anyplex II HPV28 PCR assay for genotyping and semi-quantifying 28 genital HPV genotypes, including 12 high-risk HPVs (HR-HPV). Socio-demographic and health data were collected through e-questionnaires.

RESULTS

Any-HPV genotype (any of 28 assessed) was detected in 38% of the study cohort at mid-gestation and 28% at delivery, and HR-HPVs in 24% and 16%, respectively. The most prevalent genotype was HPV16: 6% at mid-gestation and 4% at delivery. Persistence of Any-HPV genotype was 52%, as was HR-HPV genotype-specific persistence. A short pre-conception relationship with the child's father and alcohol intake during pregnancy increased HPV infection risk at both time points. Low viral load at mid-gestation was associated with clearance of HPV infections at delivery.

CONCLUSION

HPV prevalence was higher at mid-gestation compared with delivery, and low viral load was associated with clearance of HPV at delivery.

HPV infection upregulates the expression of ZNT-1 in condyloma acuminatum

Condyloma acuminata (CA) are benign anogenital warts caused by human papillomavirus (HPV) infection with a high recurrence rate. Despite its high contagiousness, high recurrence rate and potential for malignant transformation, effective treatments for CA have not yet been developed. Accordingly, it is necessary to clarify the mechanisms underlying CA development. Zinc (Zn) is stably maintained in the weight of human body. Skin is the third most Zn-abundant tissue in the body. Zn is present as a divalent ion (Zn2+) in cells and does not need a redox reaction upon crossing the cellular membrane. Zn transporters (ZnTs; SLC30A) and Irt-like proteins (ZIPs; SLC39A) are involved in Zn2+ efflux and uptake, respectively. ZnT1 is one of the ZnTs, which associates with the development of HPV. However, the role of ZnT1 regulation in the CA caused by HPV infection remains unknown. A multigroup case-control study was designed to investigate the expression and significance of the ZnT1 in patients with CA infected with HPV and in normal vulva controls. ZnT1 was assessed by immunohistochemistry in 44 patients with CA at Zhongnan Hospital of Wuhan University 2019-2020. Samples were analyzed by paraffin embedding and sectioning and hematoxylin-eosin and immunohistochemical staining. Immunohistochemical methods detected specific, dark brown, positive staining of ZnT1 in the keratinocytes of epidermis. We verified that the expression levels of ZnT1 that interact with HPV were upregulated in the CA groups independently of genotype compared with the control group. And then we found that the HPV risk grade in CA patients has a certain correlation with ZnT1 expression. These findings showed that HPV infection upregulated the expression of ZnT1 in CA. Additionally, there were obvious differences in the expression of ZnT1 between the different HPV risk grade infection groups. The higher the HPV risk grade, the stronger the ZNT1 protein expression. This study provided new insights into the sign pathway to HPV infection.

A proposed new generation of evidence-based microsimulation models to inform global control of cervical cancer

Health decision models are the only available tools designed to consider the lifetime natural history of human papillomavirus (HPV) infection and pathogenesis of cervical cancer, and the estimated long-term impact of preventive interventions. Yet health decision modeling results are often considered a lesser form of scientific evidence due to the inherent needs to rely on imperfect data and make numerous assumptions and extrapolations regarding complex processes. We propose a new health decision modeling framework that de-emphasizes cytologic-colposcopic-histologic diagnoses due to their subjectivity and lack of reproducibility, relying instead on HPV type and duration of infection as the major determinants of subsequent transition probabilities. We posit that the new model health states (normal, carcinogenic HPV infection, precancer, cancer) and corollary transitions are universal, but that the probabilities of transitioning between states may vary by population. Evidence for this variability in host response to HPV infections can be inferred from HPV prevalence patterns in different regions across the lifespan, and might be linked to different average population levels of immunologic control of HPV infections. By prioritizing direct estimation of model transition probabilities from longitudinal data (and limiting reliance on model-fitting techniques that may propagate error when applied to multiple transitions), we aim to reduce the number of assumptions for greater transparency and reliability. We propose this new microsimulation model for critique and discussion, hoping to contribute to models that maximally inform efficient strategies towards global cervical cancer elimination.

Persistent Human Papillomavirus Infection

Simple Summary

The success of HPV as an infectious agent lies not within its ability to cause disease, but rather in the adeptness of the virus to establish long-term persistent infection. The ability of HPV to replicate and maintain its genome in a stratified epithelium is contingent on the manipulation of many host pathways. HPVs must abrogate host anti-viral defense programs, perturb the balance of cellular proliferation and differentiation, and hijack DNA damage signaling and repair pathways to replicate viral DNA in a stratified epithelium. Together, these characteristics contribute to the ability of HPV to achieve long-term and persistent infection and to its evolutionary success as an infectious agent.

Abstract

Persistent infection with oncogenic human papillomavirus (HPV) types is responsible for ~5% of human cancers. The HPV infectious cycle can sustain long-term infection in stratified epithelia because viral DNA is maintained as low copy number extrachromosomal plasmids in the dividing basal cells of a lesion, while progeny viral genomes are amplified to large numbers in differentiated superficial cells. The viral E1 and E2 proteins initiate viral DNA replication and maintain and partition viral genomes, in concert with the cellular replication machinery. Additionally, the E5, E6, and E7 proteins are required to evade host immune responses and to produce a cellular environment that supports viral DNA replication. An unfortunate consequence of the manipulation of cellular proliferation and differentiation is that cells become at high risk for carcinogenesis.

Potential Effects of Human Papillomavirus Type Substitution, Superinfection Exclusion and Latency on the Efficacy of the Current L1 Prophylactic Vaccines

There are >200 different types of human papilloma virus (HPV) of which >51 infect genital epithelium, with ~14 of these classed as high-risk being more commonly associated with cervical cancer. During development of the disease, high-risk types have an increased tendency to develop a truncated non-replicative life cycle, whereas low-risk, non-cancer-associated HPV types are either asymptomatic or cause benign lesions completing their full replicative life cycle. HPVs can also be present as non-replicative so-called “latent” infections and they can also show superinfection exclusion, where cells with pre-existing infections with one type cannot be infected with a different HPV type. Thus, the HPV repertoire and replication status present in an individual can form a complex dynamic meta-community which changes with respect to both time and exposure to different HPV types. In light of these considerations, it is not clear how current prophylactic HPV vaccines will affect this system and the potential for iatrogenic outcomes is discussed in light of recent outcome data.

Expanding the upper age limit for cervical cancer screening: a protocol for a nationwide non-randomised intervention study

INTRODUCTION

Cervical cancer screening ceases between the ages of 60 and 65 in most countries. Yet, a relatively high proportion of cervical cancers are diagnosed in women above the screening age. This study will evaluate if screening of women aged 65-69 years may result in increased detection of cervical intraepithelial neoplasia grade 2 or worse (CIN2+) compared with women not invited to screening. Invited women may choose between general practitioner (GP)-based screening or cervico-vaginal self-sampling. Furthermore, the study will assess if self-sampling is superior to GP-based screening in reaching long-term unscreened women.

METHODS AND ANALYSIS

This population-based non-randomised intervention study will include 10 000 women aged 65-69 years, with no record of a cervical cytology sample or screening invitation in the 5 years before inclusion. Women who have opted-out of the screening programme or have a record of hysterectomy or cervical amputation are excluded. Women residing in the Central Denmark Region (CDR) are allocated to the intervention group, while women residing in the remaining four Danish regions are allocated to the reference group. The intervention group is invited for human papillomavirus-based screening by attending routine screening at the GP or by requesting a self-sampling kit. The reference group receives standard care which is the opportunity to have a cervical cytology sample obtained at the GP or by a gynaecologist. The study started in April 2019 and will run over the next 4.5 years. The primary outcome will be the proportion of CIN2+ detected in the intervention and reference groups. In the intervention group, the proportion of long-term unscreened women attending GP-based screening or self-sampling will be compared.

ETHICS AND DISSEMINATION

The study has been submitted to the Ethical Committee in the CDR which deemed that the study was not notifiable to the Committee and informed consent is therefore not required. The study is approved by the Danish Data Protection Regulation and the Danish Patient Safety Authority. Results will be disseminated in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04114968.

Rates of New Human Papillomavirus Detection and Loss of Detection in Middle-aged Women by Recent and Past Sexual Behavior

BACKGROUND

Understanding the source of newly detected human papillomavirus (HPV) in middle-aged women is important to inform preventive strategies, such as screening and HPV vaccination.

METHODS

We conducted a prospective cohort study in Baltimore, Maryland. Women aged 35-60 years underwent HPV testing and completed health and sexual behavior questionnaires every 6 months over a 2-year period. New detection/loss of detection rates were calculated and adjusted hazard ratios were used to identify risk factors for new detection.

RESULTS

The new and loss of detection analyses included 731 women, and 104 positive for high-risk HPV. The rate of new high-risk HPV detection was 5.0 per 1000 woman-months. Reporting a new sex partner was associated with higher detection rates (adjusted hazard ratio, 8.1; 95% confidence interval, 3.5-18.6), but accounted only for 19.4% of all new detections. Among monogamous and sexually abstinent women, new detection was higher in women reporting ≥5 lifetime sexual partners than in those reporting <5 (adjusted hazard ratio, 2.2; 95% confidence interval, 1.2-4.2).

CONCLUSION

Although women remain at risk of HPV acquisition from new sex partners as they age, our results suggest that most new detections in middle-aged women reflect recurrence of previously acquired HPV.