Screening outcome of HPV-vaccinated women: Data from the Danish Trial23 cohort study.

BACKGROUND: Danish women-who were HPV-vaccinated as girls-are now reaching an age where they are invited to cervical cancer screening. Because of their expected lower cervical cancer risk, we must reassess our screening strategies. We analyzed Danish HPV-vaccinated women's outcomes after the first screening test at age 23. METHODS AND FINDINGS: Our study was embedded in Danish routine cytology-based screening. We conducted an observational study and included women born in 1994, offered the 4-valent HPV vaccine at age 14, and subsequently invited to screening at age 23. Cervical cytology was used for diagnostics and clinical management. Residual material was HPV tested with Cobas® 4800/6800. The most severe histology diagnosis within 795 days of screening was found through linkage with the Danish National Pathology Register. We calculated the number of women undergoing follow-up (repeated testing and/or colposcopy) per detected cervical intraepithelial neoplasia (CIN2+). A total of 6021 women were screened; 92% were HPV-vaccinated; 12% had abnormal cytology; 35% were high-risk HPV-positive, including 0.9% HPV16/18 positive, and 20% had follow-up. In women that were cytology-abnormal and HPV-positive (Cyt+/HPV+), 610 (98.5%) had been followed up, and 138 CIN2+ cases were diagnosed, resulting in 4.4 (95% CI 3.9-5.2) women undergoing follow-up per detected CIN2+. In contrast to recommendations, 182 (12.2%) cytology-normal and HPV-positive (Cyt-/HPV+) women were followed up within 795 days, and 8 CIN2+ cases were found, resulting in 22.8 (95% CI 13.3-59.3) women undergoing follow-up per detected CIN2+. CONCLUSION: Overall, HPV prevalence was high in HPV-vaccinated women, but HPV16/18 had largely disappeared. In the large group of cytology-normal and HPV-positive women, 23 had been followed up per detected CIN2+ case. Our data indicated that primary HPV screening of young HPV-vaccinated women would require very effective triage methods to avoid an excessive follow-up burden. TRIAL REGISTRATION: Trial registration number: NCT0304955.

Cervical cancer survivors and health care use: A Danish population-based register study.

OBJECTIVE: To evaluate the impact of a cervical cancer (CC) diagnosis on use of health care and prescription drugs. METHODS: This population-based register-study included Danish women aged 23-59 years and diagnosed with CC in 2001-2005. Women with a cervical screening outcome were used as comparison group. We obtained number of contacts to general practitioners (GPs), hospitals, psychologists/psychiatrists and defined daily doses (DDD) of analgesic/psychotropic prescription drugs. A difference-in-differences-design was used to estimate effect of a CC diagnosis on health-care use from five-year periods before and after the diagnosis/screening outcome. RESULTS: In total, 926 women with CC and 1,004,759 women without cancer were included. In five years following the date of CC diagnosis, CC patients had increased their use of GPs with 8.6 (95% CI 4.8-12.4) contacts more than women in the comparison group, and with 4.12 (95% CI 3.99-4.25) more hospital contacts. In contrast, use of psychologists/psychiatrists was low and largely unaffected by the CC diagnosis. For use of prescription drugs, analgesics increased with 80 (95% CI 60-100) DDD more in CC patients than in comparison women, and for psychotropics with 304 (95% CI 261-347) DDD more. CONCLUSIONS: A CC diagnosis was followed by an increase in use of GPs, hospitals, and analgesic/psychotropic prescription drugs, while use of psychologist/psychiatrist was largely unaffected. This pattern may indicate that pain/mental health concerns after CC either persisted or were alleviated by other means only.

Prevalence of high-risk human papillomavirus after HPV-vaccination in Denmark.

Vaccination against human papillomavirus (HPV) has been introduced as a public health initiative in many countries, including Denmark since October 2008. It is important to monitor postimplementation effectiveness of HPV-vaccination at the population-level. We studied HPV-prevalence after first invitation to screening at age 23 years in women offered the quadrivalent HPV-vaccine at the age of 14 years. Randomly selected screening samples from women born in 1994 in four out of five Danish regions were subjected to analysis for HPV in addition to routine cytology. Cobas4800 was used in all participating pathology departments. Data from a Danish prevaccination cross-sectional study using Hybrid Capture 2, and a Danish split-sample study using Cobas4800 were used for comparison. In the period from February 2017 to April 2019, 6233 screening samples from women born in 1994 were selected for HPV-analysis; 27 samples had no HPV-test and 3 samples had no HPV-diagnosis, leaving 6203 samples with an HPV-diagnosis. Prevalence of any high-risk (HR) HPV was 35%; only 0.9% were positive for vaccine HPV types 16/18 while the remaining 34% were positive for other HR HPV. When comparing with prevaccination prevalence data, HPV-16/18 decreased by 95%; RR = 0.05 (95% CI 0.04-0.06), while other HR HPV remained fairly constant; RR = 0.88 (95% CI 0.82-0.94) and RR = 0.95 (95% CI 0.88-1.03), respectively. One-third of women vaccinated as girls with the quadrivalent HPV-vaccine were HR HPV-positive at time of first invitation to screening. Vaccine HPV-types 16 and 18 were almost eliminated, while the prevalence of nonvaccine HR HPV-types remained constant.

Conization and healthcare use: a population-based register study.

The aim of this study was to assess whether negative psychological consequences of conization reported in questionnaire studies translated into increased use of the healthcare services that could relieve such symptoms. This was a population-based register study comparing women undergoing conization with a control group of women with normal cytology results. Data were derived from Danish registers. Using the difference-in-differences method, we measured contacts with general practitioners (GPs), hospitals, psychiatrist/psychologists, and use of anxiolytic and antidepressant prescription drugs over 5 years 'before' and 'after' the conization in the study group, and in comparable periods in the control group. During the 'before' period, women who later had a conization had greater contact with GPs and hospitals, and slightly more contact with psychiatrist/psychologists, than control women. In both groups, healthcare use increased significantly from the 'before' to the 'after' period. For contacts with GPs and hospitals, the increase was significantly larger for the conization group than for the control group, but this could be attributed to the standard postconization follow-up process. In the 'before' period, women who later had a conization used fewer drugs than women of the control-group, but their drug use increased similarly over time. The conization event did not result in an increased use of the healthcare services that could relieve potential negative side effects. However, women who underwent a conization seemed to constitute a select group as they already used GPs and hospitals more frequently, and anxiolytic and antidepressant drugs less frequently, than other women in the years 'before' the conization event.

Danish method study on cervical screening in women offered HPV vaccination as girls (Trial23): a study protocol.

INTRODUCTION: The first birth cohorts of women offered human papillomavirus (HPV) vaccination as girls are now entering cervical screening. However, there is no international consensus on how to screen HPV vaccinated women. These women are better protected against cervical cancer and could therefore be offered less intensive screening. Primary HPV testing is more sensitive than cytology, allowing for a longer screening interval. The aim of Trial23 is to investigate if primary HPV testing with cytology triage of HPV positive samples is a reasonable screening scheme for women offered HPV vaccination as girls. METHODS: Trial23 is a method study embedded in the existing cervical screening programme in four out of five Danish regions. Without affecting the screening programme, women born in 1994 are randomised to present screening with liquid-based cytology every third year (present programme arm) or present screening plus an HPV test (HPV arm). The study started 1 February 2017 and will run over three screening rounds corresponding to 7-8 years. ANALYSES: The primary endpoint is cervical intraepithelial neoplasia grade 3 or above. The trial is undertaken as a non-inferiority study including intention-to-treat and per-protocol analyses. The potential effect of primary HPV screening with a 6-year interval will be calculated from the observed data. ETHICS AND DISSEMINATION: The study protocol has been submitted to the ethical committee and deemed a method study. All women are screened according to routine guidelines. The study will contribute new evidence on the future screening of HPV vaccinated birth cohorts of women. All results will be published in open-access journal. TRIAL REGISTRATION: NCT03049553; Pre-results.

Cervical screening in Denmark - a success followed by stagnation.

INTRODUCTION: Despite an intensive screening activity, the incidence of cervical cancer in Denmark has remained stable for the last 15 years, while regional differences have increased. To search for explanations, we investigated possible weaknesses in the screening program. MATERIAL AND METHODS: Data on the screen-targeted women were retrieved from Statistics Denmark. Data on screening activity were retrieved from the annual reports from 2009 to 2015 on quality of cervical screening. Coverage was calculated as proportion of screen-targeted women with at least one cytology sample within recommended time intervals. Insufficient follow-up was calculated as proportion of abnormal and unsatisfactory samples not followed up within recommended time intervals. Diagnostic distribution was calculated for samples with a satisfactory cytology diagnosis. RESULTS: Coverage remained stable at 75%-76% during the study period. Annually, approximately 100,000 women are screened before they are eligible for invitation, and 600,000 invitations and reminders are issued resulting in screening of 200,000 women. In 2009, 21% of abnormal and unsatisfactory samples were not followed up within the recommended time interval; a proportion that had decreased to 15% in 2015. Overall, 11% of satisfactory samples with a cytology diagnosis were abnormal, but with surprising variation from 6% to 15% across regions. DISCUSSION: The success of a screening program depends first of all on coverage and timely follow-up of abnormal findings. Our analysis indicated that the currently high incidence of cervical cancer in Denmark may partly be due to low screening coverage. Also worrisome is a high proportion of non-timely follow-up of abnormal findings. Innovative ways to improve coverage and follow-up are urgently needed.

Human papillomavirus self-sampling for screening nonattenders: Opt-in pilot implementation with electronic communication platforms.

In organized cervical screening programs, typically 25% of the invited women do not attend. The Copenhagen Self-sampling Initiative (CSi) aimed to gain experiences on participation among screening nonattenders in the Capital Region of Denmark. Here, we report on the effectiveness of different communication platforms used in the pilot with suggestions for strategies prior to a full-implementation. Moreover, an innovative approach using self-sampling brushes with unique radio frequency identification chips allowed for unprecedented levels patient identification safety. Nonattenders from the capital region of Denmark were identified via the organized national invitation module. Screening history was obtained via the nationwide pathology registry. Twenty-four thousand women were invited, and as an alternative to the regular communication platforms (letter and phone), women could request a home test via a mobile-friendly webpage. Instruction material and video-animation in several languages were made available online. Chi-square test was used to test differences. Out of all invited, 31.7% requested a home test, and 20% returned it to the laboratory. In addition, 10% were screened at the physician after receiving the invitation. Stratified by screening history, long-term unscreened women were less likely to participate than intermittently screened women (28% vs. 16%, p < 0.001). Of all contacts received, 64% (63-65) came via letter, and 31% (95CI: 30-32%) via webpage/mobile-app. Self-sampling was well-accepted among nonattenders. Adopting modern technology-based platforms into the current organized screening program would serve as a convenient communication method between health authority and citizens, allowing easy access for the citizen and reducing the work load in administrating self-sampling approaches.

The Danish Quality Database for Cervical Cancer Screening.

AIM OF DATABASE: To monitor and improve the quality of the Danish national cervical cancer screening program, an annual report is published, including nine quality indicators. STUDY POPULATION: The screening target group consisted of 1.5 million Danish women aged 23-64 years, but in the calculation of quality indicators, the dataset varies according to indicators being Danish women, cervical cancer cases, or cytology samples. MAIN VARIABLES: The variables include the number of cytology samples per pathology laboratory, participation rate, percentage of unsatisfactory samples, diagnostic sensitivity and specificity, percentage of samples answered within ≤10 days, percentage of atypical squamous cells of undetermined significance samples in women aged >30 years with human papillomavirus-triage, coverage, percentage of non-normal samples not followed up according to recommendations, number of incident cervical cancers, incidence of cervical cancer in the past 5 years, and upcoming percentage of incident cervical cancers undergoing audit. DESCRIPTIVE DATA: Annual reports have been published since 2009. Better fulfillment of quality standards has been seen for the size of pathology departments, percentage of unsatisfactory samples, percentage of atypical squamous cells of undetermined significance with human papillomavirus-triage, and a slight decrease in the percentage of non-normal samples not followed up within the recommended time intervals. Stable patterns have been observed for participation rate, coverage, and number of incident cervical cancer cases. With a coverage of 75%, and with presently 16% of non-normal samples not followed up in a timely manner, there is definitely a scope for improvement in the screening program. CONCLUSION: The database has pinpointed the strengths and weaknesses of the national cervical cancer screening program. Measures to enhance participation rate/coverage and to improve follow-up of non-normal cytology samples are warranted.

Differential Detection of Human Papillomavirus Genotypes and Cervical Intraepithelial Neoplasia by Four Commercial Assays.

Laboratories now can choose from >100 human papillomavirus (HPV) assays for cervical screening. Our previous analysis based on the data from the Danish Horizon study, however, showed that four widely used assays, Hybrid Capture 2 (HC2), cobas, CLART, and Aptima, frequently do not detect the same HPV infections. Here, we determined the characteristics of the concordant samples (all four assays returning a positive HPV test result) and discordant samples (all other HPV-positive samples) in primary cervical screening at 30 to 65 years of age (n = 2,859) and in a concurrent referral population from the same catchment area (n = 885). HPV testing followed the manufacturers' protocols. Women with abnormal cytology were managed according to the routine recommendations. Cytology-normal/HPV-positive women were invited for repeated testing in 18 months. Screening history and histologically confirmed cervical intraepithelial neoplasia (CIN) in 2.5 years after the baseline testing were determined from the national pathology register. HPV-positive women undergoing primary screening having concordant samples were more likely to harbor high-risk infections and less likely to harbor only low-risk infections than women with discordant samples. Additionally, assay signal strengths were substantially higher in concordant samples. More than 80% of ≥CIN2 results were found for women with concordant samples, and no ≥CIN2 results were found when the infection was detected by only one assay. These patterns were similar in the referral population despite the younger age and higher number of HPV infections. HPV test result discordance identified a cluster of low-risk HPV infections that were hardly ever associated with high-grade CIN and, almost exclusively, represented false-positive screening findings.

Cross-reactivity profiles of hybrid capture II, cobas, and APTIMA human papillomavirus assays: split-sample study.

BACKGROUND: High-risk Human Papillomavirus (HPV) testing is replacing cytology in cervical cancer screening as it is more sensitive for preinvasive cervical lesions. However, the bottleneck of HPV testing is the many false positive test results (positive tests without cervical lesions). Here, we evaluated to what extent these can be explained by cross-reactivity, i.e. positive test results without evidence of high-risk HPV genotypes. The patterns of cross-reactivity have been thoroughly studied for hybrid capture II (HC2) but not yet for newer HPV assays although the manufacturers claimed no or limited frequency of cross-reactivity. In this independent study we evaluated the frequency of cross-reactivity for HC2, cobas, and APTIMA assays. METHODS: Consecutive routine cervical screening samples from 5022 Danish women, including 2859 from women attending primary screening, were tested with the three evaluated DNA and mRNA HPV assays. Genotyping was undertaken using CLART HPV2 assay, individually detecting 35 genotypes. The presence or absence of cervical lesions was determined with histological examinations; women with abnormal cytology were managed as per routine recommendations; those with normal cytology and positive high-risk HPV test results were invited for repeated testing in 18 months. RESULTS: Cross-reactivity to low-risk genotypes was detected in 109 (2.2 %) out of 5022 samples on HC2, 62 (1.2 %) on cobas, and 35 (0.7 %) on APTIMA with only 10 of the samples cross-reacting on all 3 assays. None of the 35 genotypes was detected in 49 (1.0 %), 162 (3.2 %), and 56 (1.1 %) samples, respectively. In primary screening at age 30 to 65 years (n = 2859), samples of 72 (25 %) out of 289 with high-risk infections on HC2 and < CIN2 histology were due to cross-reactivity. On cobas, this was 106 (26 %) out of 415, and on APTIMA 48 (21 %) out of 224. CONCLUSIONS: Despite manufacturer claims, all three assays showed cross-reactivity. In primary cervical screening at age ≥30 years, cross-reactivity accounted for about one quarter of false positive test results regardless of the assay. Cross-reactivity should be addressed in EU tenders, as this primarily technical shortcoming imposes additional costs on the screening programmes.

Human Papillomavirus Assays and Cytology in Primary Cervical Screening of Women Aged 30 Years and Above.

In women aged ≥ 30 years, Human Papillomavirus testing will replace cytology for primary cervical screening. We compared Hybrid Capture 2 (HC2), cobas, CLART, and APTIMA HPV assays with cytology on 2869 SurePath samples from women undergoing routine screening at 30-65 years in Copenhagen, Denmark. Women with cytological abnormalities were managed according to routine recommendations, with 92% completeness. Those with cytology-normal/HPV-positive samples (on any of the four assays) were invited for repeated cytology and HPV testing in 1.5 year, and 58% had additional testing. HPV testing detected more ≥ CIN3 than cytology (HC2: 35, cobas, CLART: 37, APTIMA: 34, cytology: 31), although statistically the differences were not significant. Cobas and CLART detected significantly more ≥ CIN2 than cytology (cobas, CLART: 49, cytology: 39). The proportion of women with false-positive test results (positive test results without ≥ CIN3) varied between 3.3% with cytology and 14.9% with cobas. All HPV assays led to significantly more false-positive tests, whereas compared to HC2 cobas and CLART were associated with a significantly higher and APTIMA with a significantly lower proportion. Detection of CIN1 was particularly increased for the three DNA assays. With APTIMA combined with cytological triage, about 20% more women were referred for colposcopy than with cytology screening. With the three DNA assays, the increase was ≥ 50%. The number of women with repeated testing was twice as high with APTIMA and almost five times as high with cobas compared to cytology. To our knowledge, Horizon was the only study set in routine practice that compared more than two HPV assays in the same women while also ascertaining the histological status of women with normal cytology/HPV-positive test results. HPV-based screening of Danish women aged 30-65 detected more high-grade CIN but decreased the screening specificity, and increased the demand for additional testing.

Cervical histology after routine ThinPrep or SurePath liquid-based cytology and computer-assisted reading in Denmark.

BACKGROUND: We compared the sensitivity and specificity of liquid-based cytology (LBC) and computer-assisted reading for SurePath/FocalPoint and ThinPrep with those of manually read conventional cytology in routine cervical screening in four Danish laboratories. METHODS: Using data from five nationwide registers, technological phases were identified by slide preparation, reading technique, and triage of borderline cytology. Trends in the detection of cervical intraepithelial neoplasia (CIN) were an indicator of the technology's relative sensitivity, and trends in false-positive tests an indicator of relative specificity. RESULTS: At 23-29 years, SurePath/FocalPoint statistically significantly increased the detection of ⩾CIN3 by 85% compared with manually read conventional cytology. The 11% increase with ThinPrep was not significant. At 30-44 years, the increase with SurePath/FocalPoint was 58%; the 16% increase with ThinPrep was not significant. At 45-59 years, both technologies led to nonsignificant decreases in the detection. SurePath/FocalPoint doubled the frequency of false-positive tests at any age. With ThinPrep, these proportions remained the same at 23-29 years, but decreased by two-thirds at 45-59 years. In a fourth laboratory with continuous use of manually read conventional cytology, no such trends were seen. CONCLUSIONS: The sensitivity and specificity of modern LBC and computer-assisted reading technologies may be brand- and age-dependent.

Abnormal cervical cytology and health care use: a population-based register study.

OBJECTIVE: This study aimed to assess the long-term use of health care services in women with abnormal cytology results compared to women with normal cytology results. METHODS: We did a nationwide population-based study, using women aged 23 to 59years participating in the national organized cervical cancer screening program. We included a study population of 40,153 women with abnormal cytology (exposed) and 752,627 women with normal cytology (non-exposed). We retrieved data from the Danish Civil Registration System, the Danish Pathology Data Bank, the National Health Service, the National Patient and the National Prescription Register. We calculated the frequencies of contacts to general practitioner (GP), to private psychiatrist and/or psychologist, admissions to hospitals and use of prescription drugs. These frequencies were calculated separately in the 5-year period "before" the cytology result and for the 5-year period "after" the result. RESULTS: During the "before" period exposed women had more contacts to GPs, more contacts to psychologists/psychiatrist, and more hospital admissions than non-exposed women. In both exposed and non-exposed women, health care use increased from the "before" to the "after" period. This increase was significantly higher for exposed than non-exposed women regarding contacts to GP, admissions to hospitals, and drug use. CONCLUSION: Women with abnormal cytology results constitute a selected group with a higher health care use than other women even before they have the abnormal cytology. This difference is further enhanced after the abnormal cytology result.

A daunting challenge: Human Papillomavirus assays and cytology in primary cervical screening of women below age 30years.

We compared cytology with Hybrid Capture 2 (HC2), cobas, CLART and APTIMA Human Papillomavirus (HPV) assays in primary cervical screening at age 23-29 years based on data from the Danish Horizon study. SurePath samples were collected from 1278 women undergoing routine cytology-based screening. Abnormal cytology was managed according to the routine recommendations, and women with cytology-normal/HPV-positive samples were invited for repeated cytology and HPV testing in 1.5 years. Loss to follow-up was similar between HPV assays. ⩾ CIN3 was detected in 44 women. The sensitivity of HC2 for ⩾ CIN3 was 95% (95% confidence interval (CI): 85-99), of cobas 98% (95% CI: 88-100), of CLART 100% (95% CI: 92-100), of APTIMA 82% (95% CI: 67-92), and of cytology 59% (95% CI: 43-74). Specificity for ⩾ CIN3 varied between 61% (95% CI: 59-64) for cobas and 75% (95% CI: 73-78) for APTIMA, and was 94% (95% CI: 93-96) for cytology. Similar results were observed for ⩾ CIN2 (N = 68). HPV screening with cytological triage doubled the number of colposcopies compared to cytology screening, and increased the frequency of repeated testing by four (APTIMA) to seven (cobas) times. The positive predictive value of a referral for colposcopy was relatively high for all screening tests (⩾ 30% for ⩾ CIN3, and ⩾ 50% for ⩾ CIN2). CIN1 was detected by cytology in ∼ 1% of women, and in ∼ 2% by any of the four HPV assays. Although highly sensitive, HPV-based screening of young Danish women should be approached cautiously, as it resulted in large reductions in specificity, and increased the demand for additional testing.

Comparison of three human papillomavirus DNA assays and one mRNA assay in women with abnormal cytology.

OBJECTIVE: To compare the clinical characteristics of four human papillomavirus (HPV) assays: hybrid capture 2 (HC2), cobas, CLART, and APTIMA in Danish women with abnormal cytology. METHODS: SurePath samples from 367 consecutive women from Copenhagen, with atypical squamous cells of undetermined significance or worse, were tested with the four assays. These women were routinely recommended for repeated testing or were referred for colposcopy. Their worst histological diagnosis in 29 months from baseline was retrieved from the Danish National Pathology Data Bank. RESULTS: Of the 367 women, 16 (4%) had no follow-up, 232 (63%) had

HPV prevalence and genotype distribution in a population-based split-sample study of well-screened women using CLART HPV2 human papillomavirus genotype microarray system.

BACKGROUND: Human papillomavirus (HPV) genotyping assays are becoming increasingly attractive for use in mass screening, as they offer a possibility to integrate HPV screening with HPV vaccine monitoring, thereby generating a synergy between the two main modes of cervical cancer prevention. The Genomica CLART HPV2 assay is a semi-automated PCR-based microarray assay detecting 35 high-risk and low-risk HPV genotypes. However, few reports have described this assay in cervical screening. An aim of the present study, Horizon, was to assess the prevalence of high-risk HPV infections in Copenhagen, Denmark, an area with a high background risk of cervical cancer where women aged 23-65 years are targeted for organized screening. METHODS: Material from 5,068 SurePath samples of women participating in routine screening and clinical follow-up of cervical abnormalities was tested using liquid based cytology, CLART HPV2 and Hybrid Capture 2 (HC2). RESULTS: At least one of the 35 defined genotypes was detected by CLART in 1,896 (37%) samples. The most frequent high-risk genotypes were HPV 16 (7%), HPV 52 (5%), and HPV 31 (4%). The most frequent low-risk genotypes were HPV 53 (5%), HPV 61 (4%), and HPV 66 (3%). Among 4,793 women targeted by the screening program (23-65 years), 1,166 (24%) tested positive for one or more of the 13 high-risk genotypes. This proportion decreased from 40% at age 23-29 years to 10% at age 60-65 years. On HC2, 1,035 (20%) samples were positive for any high-risk and thus CLART showed a higher analytical sensitivity for 13 high-risk HPV genotypes than HC2, and this was found in all age-groups and in women normal cytology. CONCLUSIONS: CLART performed well with a positive reproducibility for high-risk genotypes of 86%, and a negative reproducibility of 97%. This report furthermore updates the genotype distribution in Denmark prior to the inclusion of the HPV-vaccinated cohorts into the screening program, and as such represents a valuable baseline for future vaccine impact assessment.

Cervical cancer screening at crossroads.

Cervical screening has been one of the most successful public health prevention programmes. For 50 years, cytology formed the basis for screening, and detected cervical intraepithelial lesions (CIN) were treated surgically to prevent progression to cancer. In a high-risk country as Denmark, screening decreased the incidence of cervical cancer from 34 to 11 per 100,000, age-standardized rate (World Standard Population). Screening is, however, also expensive; Denmark (population: 5.6 million) undertakes close to half a million tests per year, and has 6-8 CIN-treated women for each prevented cancer case. The discovery of human papillomavirus (HPV) as the cause of cervical cancer dramatically changed perspectives for disease control. Screening with HPV testing was launched around 1990, and preventive HPV vaccination was licensed in 2006. Long-term randomized controlled trials (RCT) demonstrated that HPV testing provides better protection against cervical cancer than cytology, but it requires extra repeated testing. HPV vaccination RCTs, furthermore, have proved that HPV vaccination protects against vaccine-type high-grade CIN in women vaccinated prior to sexual activity, but less so in women vaccinated later. The challenge now is therefore to find an algorithm for screening of a heterogeneous population including non-vaccinated women; women vaccinated prior to start of sexual activity; and women vaccinated later.

Disagreement between human papillomavirus assays: an unexpected challenge for the choice of an assay in primary cervical screening.

We aimed to determine the disagreement in primary cervical screening between four human papillomavirus assays: Hybrid Capture 2, cobas, CLART, and APTIMA. Material from 5,064 SurePath samples of women participating in routine cervical screening in Copenhagen, Denmark, was tested with the four assays. Positive agreement between the assays was measured as the conditional probability that the results of all compared assays were positive given that at least one assay returned a positive result. Of all 5,064 samples, 1,679 (33.2%) tested positive on at least one of the assays. Among these, 41% tested positive on all four. Agreement was lower in women aged ≥ 30 years (30%, vs. 49% at <30 years), in primary screening samples (29%, vs. 38% in follow-up samples), and in women with concurrent normal cytology (22%, vs. 68% with abnormal cytology). Among primary screening samples from women aged 30-65 years (n = 2,881), 23% tested positive on at least one assay, and 42 to 58% of these showed positive agreement on any compared pair of the assays. While 4% of primary screening samples showed abnormal cytology, 6 to 10% were discordant on any pair of assays. A literature review corroborated our findings of considerable disagreement between human papillomavirus assays. This suggested that the extent of disagreement in primary screening is neither population- nor storage media-specific, leaving assay design differences as the most probable cause. The substantially different selection of women testing positive on the various human papillomavirus assays represents an unexpected challenge for the choice of an assay in primary cervical screening, and for follow up of in particular HPV positive/cytology normal women.

Prevalence of Human Papillomavirus infection in unselected SurePath samples using the APTIMA HPV mRNA assay.

The APTIMA Human Papillomavirus (HPV) Assay detects E6/E7 mRNA from 14 human papillomavirus genotypes. Horizon was a population-based split-sample study among well-screened women, with an aim to compare APTIMA, Hybrid Capture 2 (HC2), and liquid-based cytology (LBC) using SurePath samples. APTIMA testing on the PANTHER platform, and HC2 testing on the Rapid Capture System were performed in accordance with protocols agreed on with the manufacturers before the study, on 5070 consecutive, routine, cervical cytology samples from Copenhagen, Denmark. In this high-risk population, 17% of all samples tested positive on APTIMA, 20% of samples tested positive on HC2, and 7% of samples had abnormal cytology. Among the 4411 samples without recent abnormalities, 15% tested positive on APTIMA, 19% tested positive on HC2, and 5% had abnormal cytology. The κ coefficient of 0.75 suggested substantial agreement between APTIMA and HC2. This is the first APTIMA study using SurePath samples on the PANTHER platform. The trends in positivity rates on SurePath samples for APTIMA, HC2, and LBC were consistent with studies based on PreservCyt samples, and the agreement between the two HPV assays was substantial. The high proportions of women testing positive suggest that in countries with a high HPV prevalence, caution will be needed if HPV tests, including mRNA-based tests, are to replace LBC.

Prevalence of human papillomavirus in 5,072 consecutive cervical SurePath samples evaluated with the Roche cobas HPV real-time PCR assay.

New commercially available Human Papillomavirus (HPV) assays need to be evaluated in a variety of cervical screening settings. Cobas HPV Test (cobas) is a real-time PCR-based assay allowing for separate detection of HPV genotypes 16 and 18 and a bulk of 12 other high-risk genotypes. The aim of the present study, Horizon, was to assess the prevalence of high-risk HPV infections in an area with a high background risk of cervical cancer, where women aged 23-65 years are targeted for cervical screening. We collected 6,258 consecutive cervical samples from the largest cervical screening laboratory in Denmark serving the whole of Copenhagen. All samples were stored in SurePath media. In total, 5,072 samples were tested with cobas, Hybrid Capture 2 High Risk HPV DNA test (HC2) and liquid-based cytology. Of these, 27% tested positive on cobas. This proportion decreased by age, being 43% in women aged 23-29 years and 10% in women aged 60-65 years. HC2 assay was positive in 20% of samples, and cytology was abnormal (≥ atypical squamous cells of undetermined significance) for 7% samples. When only samples without recent abnormalities were taken into account, 24% tested positive on cobas, 19% on HC2, and 5% had abnormal cytology. The proportion of positive cobas samples was higher than in the ATHENA trial. The age-standardized cobas positivity vs. cytology abnormality was 3.9 in our study and 1.7 in ATHENA. If in Copenhagen the presently used cytology would be replaced by cobas in women above age 30 years, an extra 11% of women would based on historical data be expected to have a positive cobas test without an underlying cervical intraepithelial lesion grade 3 or worse. Countries with a high prevalence of HPV infections should therefore proceed to primary HPV-based cervical screening with caution.