Marc Arbyn

European Guidelines for Quality Assurance in Cervical Cancer Screening. Second Edition—Summary Document

European Guidelines for Quality Assurance in Cervical Cancer Screening have been initiated in the Europe Against Cancer Programme. The first edition established the principles of organised population-based screening and stimulated numerous pilot projects. The second multidisciplinary edition was published in 2008 and comprises ∼250 pages divided into seven chapters prepared by 48 authors and contributors. Considerable attention has been devoted to organised, population-based programme policies which minimise adverse effects and maximise benefits of screening. It is hoped that this expanded guidelines edition will have a greater impact on countries in which screening programmes are still lacking and in which opportunistic screening has been preferred in the past. Other methodological aspects such as future prospects of human papillomavirus testing and vaccination in cervical cancer control have also been examined in the second edition; recommendations for integration of the latter technologies into European guidelines are currently under development in a related project supported by the European Union Health Programme. An overview of the fundamental points and principles that should support any quality-assured screening programme and key performance indicators are presented here in a summary document of the second guidelines edition in order to make these principles and standards known to a wider scientific community.

Guidelines for human papillomavirus DNA test requirements for primary cervical cancer screening in women 30 years and older

Given the strong etiologic link between high‐risk HPV infection and cervical cancer high‐risk HPV testing is now being considered as an alternative for cytology‐based cervical cancer screening. Many test systems have been developed that can detect the broad spectrum of hrHPV types in one assay. However, for screening purposes the detection of high‐risk HPV is not inherently useful unless it is informative for the presence of high‐grade cervical intraepithelial neoplasia (CIN 2/3) or cancer. Candidate high‐risk HPV tests to be used for screening should reach an optimal balance between clinical sensitivity and specificity for detection of high‐grade CIN and cervical cancer to minimize redundant or excessive follow‐up procedures for high‐risk HPV positive women without cervical lesions. Data from various large screening studies have shown that high‐risk HPV testing by hybrid capture 2 and GP5+/6+‐PCR yields considerably better results in the detection of CIN 2/3 than cytology. The data from these studies can be used to guide the translation of high‐risk HPV testing into clinical practice by setting standards of test performance and characteristics. On the basis of these data we have developed guidelines for high‐risk HPV test requirements for primary cervical screening and validation guidelines for candidate HPV assays.

Liquid Compared With Conventional Cervical Cytology A Systematic Review and Meta-analysis

OBJECTIVE: To compare test performance characteristics of conventional Pap tests and liquid-based cervical cytology samples. DATA SOURCES: Eligible studies, published between 1991 and 2007, were retrieved through PubMed/EmBase searching and completed by consultation of other sources. METHODS OF STUDY SELECTION: Studies were selected if a conventional and a liquid-based sample were prepared from the same woman or when one or the other type of sample was taken from a separate but similar cohort. The current systematic review and meta-analysis is restricted to studies where all subjects were submitted to gold standard verification, based on colposcopy and histology of colposcopy-targeted biopsies, allowing computation of absolute and relative test validity for cervical intraepithelial neoplasia grade 2 or worse. Randomized trials were selected as well if all test-positive cases were verified with the same gold standard, allowing computation of the relative sensitivity. Impact of study characteristics on accuracy was assessed by subgroup meta-analyses, meta-regression, and summary receiver operating characteristic curve regression. TABULATION, INTEGRATION, AND RESULTS: The relative sensitivity, pooled from eight studies, with complete gold standard verification and from one randomized clinical trial, did not differ significantly from unity. Also, the specificity, considering high-grade and low-grade squamous intraepithelial lesions as cutoff, was similar in conventional and liquid cytology. However, a lower pooled specificity was found for liquid-based cytology when presence of atypical squamous cells of undetermined significance was the cutoff (ratio 0.91, 95% confidence interval 0.84–0.98). Differences in study characteristics did not explain interstudy heterogeneity. CONCLUSION: Liquid-based cervical cytology is neither more sensitive nor more specific for detection of high-grade cervical intraepithelial neoplasia compared with the conventional Pap test.

Metaprop: a Stata command to perform meta-analysis of binomial data

BackgroundMeta-analyses have become an essential tool in synthesizing evidence on clinical and epidemiological questions derived from a multitude of similar studies assessing the particular issue. Appropriate and accessible statistical software is needed to produce the summary statistic of interest.MethodsMetaprop is a statistical program implemented to perform meta-analyses of proportions in Stata. It builds further on the existing Stata procedure metan which is typically used to pool effects (risk ratios, odds ratios, differences of risks or means) but which is also used to pool proportions. Metaprop implements procedures which are specific to binomial data and allows computation of exact binomial and score test-based confidence intervals. It provides appropriate methods for dealing with proportions close to or at the margins where the normal approximation procedures often break down, by use of the binomial distribution to model the within-study variability or by allowing Freeman-Tukey double arcsine transformation to stabilize the variances. Metaprop was applied on two published meta-analyses: 1) prevalence of HPV-infection in women with a Pap smear showing ASC-US; 2) cure rate after treatment for cervical precancer using cold coagulation.ResultsThe first meta-analysis showed a pooled HPV-prevalence of 43% (95% CI: 38%-48%). In the second meta-analysis, the pooled percentage of cured women was 94% (95% CI: 86%-97%).ConclusionBy using metaprop, no studies with 0% or 100% proportions were excluded from the meta-analysis. Furthermore, study specific and pooled confidence intervals always were within admissible values, contrary to the original publication, where metan was used.

Accuracy of human papillomavirus testing on self-collected versus clinician-collected samples: a meta-analysis

BACKGROUND Screening for human papillomavirus (HPV) infection is more effective in reducing the incidence of cervical cancer than screening using Pap smears. Moreover, HPV testing can be done on a vaginal sample self-taken by a woman, which offers an opportunity to improve screening coverage. However, the clinical accuracy of HPV testing on self-samples is not well-known. We assessed whether HPV testing on self-collected samples is equivalent to HPV testing on samples collected by clinicians. METHODS We identified relevant studies through a search of PubMed, Embase, and CENTRAL. Studies were eligible for inclusion if they fulfilled all of the following selection criteria: a cervical cell sample was self-collected by a woman followed by a sample taken by a clinician; a high-risk HPV test was done on the self-sample (index test) and HPV-testing or cytological interpretation was done on the specimen collected by the clinician (comparator tests); and the presence or absence of cervical intraepithelial neoplasia grade 2 (CIN2) or worse was verified by colposcopy and biopsy in all enrolled women or in women with one or more positive tests. The absolute accuracy for finding CIN2 or worse, or CIN grade 3 (CIN3) or worse of the index and comparator tests as well as the relative accuracy of the index versus the comparator tests were pooled using bivariate normal models and random effect models. FINDINGS We included data from 36 studies, which altogether enrolled 154 556 women. The absolute accuracy varied by clinical setting. In the context of screening, HPV testing on self-samples detected, on average, 76% (95% CI 69-82) of CIN2 or worse and 84% (72-92) of CIN3 or worse. The pooled absolute specificity to exclude CIN2 or worse was 86% (83-89) and 87% (84-90) to exclude CIN3 or worse. The variation of the relative accuracy of HPV testing on self-samples compared with tests on clinician-taken samples was low across settings, enabling pooling of the relative accuracy over all studies. The pooled sensitivity of HPV testing on self-samples was lower than HPV testing on a clinician-taken sample (ratio 0·88 [95% CI 0·85-0·91] for CIN2 or worse and 0·89 [0·83-0·96] for CIN3 or worse). Also specificity was lower in self-samples versus clinician-taken samples (ratio 0·96 [0·95-0·97] for CIN2 or worse and 0·96 [0·93-0·99] for CIN3 or worse). HPV testing with signal-based assays on self-samples was less sensitive and specific than testing on clinician-based samples. By contrast, some PCR-based HPV tests generally showed similar sensitivity on both self-samples and clinician-based samples. INTERPRETATION In screening programmes using signal-based assays, sampling by a clinician should be recommended. However, HPV testing on a self-sample can be suggested as an additional strategy to reach women not participating in the regular screening programme. Some PCR-based HPV tests could be considered for routine screening after careful piloting assessing feasibility, logistics, population compliance, and costs. FUNDING The 7th Framework Programme of the European Commission, the Belgian Foundation against Cancer, the International Agency for Research on Cancer, and the German Guideline Program in Oncology.

Pooled analysis of the accuracy of five cervical cancer screening tests assessed in eleven studies in Africa and India.

Cervical cancer is the main cancer among women in sub‐Saharan Africa, India and other parts of the developing world. Evaluation of screening performance of effective, feasible and affordable early detection and management methods is a public health priority. Five screening methods, naked eye visual inspection of the cervix uteri after application of diluted acetic acid (VIA), or Lugols iodine (VILI) or with a magnifying device (VIAM), the Pap smear and human papillomavirus testing with the high‐risk probe of the Hybrid Capture‐2 assay (HC2), were evaluated in 11 studies in India and Africa. More than 58,000 women, aged 25–64 years, were tested with 2–5 screening tests and outcome verification was done on all women independent of the screen test results. The outcome was presence or absence of cervical intraepithelial neoplasia (CIN) of different degrees or invasive cervical cancer. Verification was based on colposcopy and histological interpretation of colposcopy‐directed biopsies. Negative colposcopy was accepted as a truly negative outcome. VIA showed a sensitivity of 79% (95% CI 73–85%) and 83% (95% CI 77–89%), and a specificity of 85% (95% CI 81–89%) and 84% (95% CI 80–88%) for the outcomes CIN2+ or CIN3+, respectively. VILI was on average 10% more sensitive and equally specific. VIAM showed similar results as VIA. The Pap smear showed lowest sensitivity, even at the lowest cutoff of atypical squamous cells of undetermined significance (57%; 95% CI 38–76%) for CIN2+ but the specificity was rather high (93%; 95% CI 89–97%). The HC2‐assay showed a sensitivity for CIN2+ of 62% (95% CI 56–68%) and a specificity of 94% (95% CI 92–95%). Substantial interstudy variation was observed in the accuracy of the visual screening methods. Accuracy of visual methods and cytology increased over time, whereas performance of HC2 was constant. Results of visual tests and colposcopy were highly correlated. This study was the largest ever done that evaluates the cross‐sectional accuracy of screening tests for cervical cancer precursors in developing countries. The merit of the study was that all screened subjects were submitted to confirmatory investigations avoiding to verification bias. A major finding was the consistently higher sensitivity but equal specificity of VILI compared with VIA. Nevertheless, some caution is warranted in the interpretation of observed accuracy measures, since a certain degree of gold standard misclassification cannot be excluded. Because of the correlation between visual screening tests and colposcopy and a certain degree of over‐diagnosis of apparent CIN2+ by study pathologists, it is possible that both sensitivity and specificity of VIA and VILI were overestimated. Gold standard verification error could also explain the surprisingly low sensitivity of HC2, which contrasts with findings from other studies.

Trends of cervical cancer mortality in the member states of the European Union

BACKGROUND Cervical cancer mortality can be avoided to a large extent by screening and treatment of screen-detected cervical lesions. However, in 2004, more than 16,000 women died from cervical cancer in the European Union (EU). In the current paper, we analyse cervical cancer mortality trends in the 27 member states since 1970 and, subsequently, try to explain how screening and other factors have driven changes. METHODS Data on number of deaths from uterine cancers and overall female populations from EU member states were extracted from the World Health Organisation mortality database. Three different reallocation rules were applied to correct cervical cancer mortality for inaccuracies in certification of cause of death of not otherwise specified uterine cancer. Joinpoint regression was used to study annual variation of corrected cervical cancer mortality in all member states. We distinguished the 15 old from the 12 new member states, which acceded to the EU in 2004 or later. For Finland, France and Romania, age-specific trends by calendar period and the standardised cohort mortality ratios by birth cohort were analysed. RESULTS Corrected age-standardised cervical cancer mortality rates have decreased significantly over the past decades in the old member states. Member states in Eastern Europe and also the Baltic states showed mortality rates that decreased at a lower intensity (Czech Republic, Poland), remained constant at a high rate (Estonia, Slovakia) or even increased (Bulgaria, Latvia, Lithuania, Romania). The standardised cohort mortality ratio indicated that mortality does not decrease further or even increase among women born after 1940. CONCLUSION Remarkable contrasts were observed on cervical cancer mortality, in particular, between the old and new member states of the EU, which might probably be explained by differences in preventive strategies. This contrast might increase in the future, unless adequate preventive measures are adopted.

Cervical cancer screening programmes and policies in 18 European countries.

A questionnaire survey was conducted by the Epidemiology Working Group of the European Cervical Cancer Screening Network, and the International Agency for Research on Cancer, IARC, between August and December 2003 in 35 centres in 20 European countries with reliable cervical cancer incidence and/or mortality data in databanks held at IARC and WHO. The questionnaire was completed by 28 centres from 20 countries. The final tables included information on 25 centres from 18 countries. Six countries had started screening in the 1960s, whereas 10 countries or regions had started at least a pilot programme by 2003. There were six invitational and nine partially invitational programmes, the rest employing opportunistic screening only. Recommended lifetime number of smears varied from seven to more than 50. Coverage of smear test within the recommended screening interval (usually 3 or 5 years) was above 80% in three countries. Screening registration took place in 13 programmes. Eight programmes reported the rates of screen-detected cervical cancers and precursor lesions. There was wide variation in the CIN3 detection rates. International guidelines and quality assurance protocols are useful for monitoring and evaluating screening programmes systematically. Our survey indicated that the recommendations as currently given are met in only few European countries. Health authorities need to consider stronger measures and incentives than those laid out in the current set of recommendations.

Comparison of liquid-based cytology with conventional cytology for detection of cervical cancer precursors: a randomized controlled trial.

CONTEXT Liquid-based cytology has been developed as an alternative for conventional cervical cytology. Despite numerous studies and systematic reviews, controversy remains about its diagnostic accuracy. OBJECTIVE To assess the performance of liquid-based cytology compared with conventional cytology in terms of detection of histologically confirmed cervical intraepithelial neoplasia (CIN). DESIGN, SETTING, AND PARTICIPANTS Cluster randomized controlled trial involving 89,784 women aged 30 to 60 years participating in the Dutch cervical screening program at 246 family practices. One hundred twenty-two practices were assigned to use liquid-based cytology and screened 49,222 patients and 124 practices were assigned to use the conventional Papanicolaou (Pap) test and screened 40,562 patients between April 2004 and July 1, 2006. Patients were followed up for 18 months through January 31, 2008. INTERVENTION Screening for CIN using liquid-based cytology or conventional papanicolaou (Pap) test and the blinded review of all follow-up of screen-positive women (blinded to the type of cytology and the initial result). MAIN OUTCOME MEASURES Intention-to-treat and per-protocol analysis of the detection rates of and positive predictive values for histologically verified CIN in both cytology systems. Outcomes are presented as crude and adjusted rate ratios (adjustment for age, urbanization, study site, and period). RESULTS The adjusted detection rate ratios for CIN grade 1+ was 1.01 (95% confidence interval [CI], 0.85-1.19); for CIN grade 2+, 1.00 (95% CI, 0.84-1.20); for CIN grade 3+, 1.05 (95% CI, 0.86-1.29); and for carcinoma, 1.69 (95% CI, 0.96-2.99). The adjusted positive predictive value (PPV) ratios, considered at several cytological cutoffs and for various outcomes of CIN did not differ significantly from unity. CONCLUSION This study indicates that liquid-based cytology does not perform better than conventional Pap tests in terms of relative sensitivity and PPV for detection of cervical cancer precursors. TRIAL REGISTRATION trialregister.nl Identifier: NTR1032.

High-risk HPV testing on self-sampled versus clinician-collected specimens: a review on the clinical accuracy and impact on population attendance in cervical cancer screening.

This review elaborates on the accuracy and feasibility of human papillomavirus (HPV) self‐sampling, i.e., offering self‐sampling of (cervico‐)vaginal cell material by women themselves in nonclinical settings for high‐risk HPV (hrHPV) detection in the laboratory, for cervical screening. To that end a bibliographic database search (PubMed) was performed to identify studies (published between January 1992 and January 2012) that compared clinical accuracy of HPV testing on self‐sampled material with that of cytology or HPV testing on clinician‐taken samples, and studies comparing response to offering HPV self‐sampling with a recall invitation. Overall, hrHPV testing on self‐samples appeared to be at least as, if not more, sensitive for cervical intraepithelial neoplasia grade 2 or worse (CIN2+) as cytology on clinician‐obtained cervical samples, though often less specific. In most studies, hrHPV testing on self‐ and clinician‐sampled specimens is similarly accurate with respect to CIN2+ detection. Variations in clinical performance likely reflect the use of different combinations of collection devices and HPV tests. Because it is known that underscreened women are at increased risk of cervical cancer, targeting non‐attendees of the screening program could improve the effectiveness of cervical screening. In developed countries offering self‐sampling has shown to be superior to a recall invitation for cytology in re‐attracting original non‐attendees into the screening program. Additionally, self‐testing has shown to facilitate access to cervical screening for women in low resource areas. This updated review of the literature suggests that HPV self‐sampling could be an additional strategy that can improve screening performance compared to current cytology‐based call‐recall programs.