Clinical accuracy of OncoPredict HPV Quantitative Typing (QT) assay on self-samples.

BACKGROUND: The VALHUDES initiative was established to assess the clinical accuracy of HPV assays to detect cervical precancers using urine and vaginal self-samples compared to cervical clinician-collected samples. Here, the clinical performance of OncoPredict HPV Quantitative Typing (QT) assay (OncoPredict QT) was evaluated. METHODS: 490 women referred to colposcopy self-collected a urine and a vaginal specimen using Colli-Pee and FLOQSwab, respectively. Subsequently, a colposcopy was performed, and a cervical sample was collected with Cervex-Brush, followed by biopsy if clinically indicated. Vaginal samples were transported dry and resuspended in 5 mL of eNAT medium, whilst cervical brushings were immediately transferred in 20 mL ThinPrep. RESULTS: The clinical sensitivity of OncoPredict HPV QT testing for CIN2+ in urine and vaginal self-samples was similar to cervical samples (ratios of 0.99 [95 % CI 0.94-1.05] and 1.00 [95 % CI 0.96-1.04]), respectively, when manufacturer's cut-offs were applied. The specificity for

High-risk HPV mRNA testing on self-samples offered to those who do not attend for organised cervical screening - real world data from the Dumfries and Galloway region in Scotland.

BACKGROUND: HPV self sampling can act as a tool to engage women in cervical screening and population based studies can inform optimal implementation of this approach. METHODS: Self sampling kits were mailed to women who had defaulted from routine screening resident in an entire territorial health board in Scotland. Kit return rates and compliance to colposcopy follow up in those who were HPV mRNA positive were assessed. Concordance of the self-sample with samples taken later at colposcopy was measured alongside PPV of an mRNA positive result for CIN2+. RESULTS: Of 4173 women invited to participate, 20.5 %, returned their kit and a greater return rate with increasing age was observed. HPV mRNA positivity was 12.0 %, and invalidity rate was approximately 3 %. Compliance to colposcopy follow up was 88.3 % and the PPV for an mRNA test for CIN2+ on a self sample was 25.6 %. hr-HPV concordance on the initial swab and the follow up swab and liquid based cytology (LBC) sample taken at colposcopy was 67.1 % and 30 % respectively. CONCLUSIONS: HPV self sampling using a "mail to all" approach is feasible in Scotland although only 1 in 5 actively responded to the offer. Future work to monitor screening behaviours in those who were invited but did not engage initially will help quantify any additional benefit(s) incurred.

Criteria for second generation comparator tests in validation of novel HPV DNA tests for use in cervical cancer screening.

While HC2 and GP5+/6+ PCR-EIA were pivotal in test validation of new HPV assays, they represent the first generation of comparator tests based upon technologies that are not in widespread use anymore. In the current guideline, criteria for second-generation comparator tests are presented that include more detailed resolution of HPV genotypes. Second-generation comparator tests should preferentially target only the 12 genotypes classified as carcinogenic (IARC-group I), and show consistent non-inferior sensitivity for CIN2+ and CIN3+ and specificity for ≤CIN1 compared to one of the first-generations comparators, in at least three validation studies using benchmarks of 0.95 for relative sensitivity and 0.98 for relative specificity. Validation should take into account used storage media and other sample handling procedures. Meta-analyses were conducted to identify the assays that fulfill these stringent criteria. Four tests fulfilled the new criteria: (1) RealTime High-Risk HPV Test (Abbott), (2) Cobas-4800 HPV test (Roche Molecular System), (3) Onclarity HPV Assay (BD Diagnostics), and (4) Anyplex II HPV HR Detection (Seegene), each evaluated in three to six studies. Whereas the four assays target 14 carcinogenic genotypes, the first two identify separately HPV16 and 18, the third assay identifies five types separately and the fourth identifies all the types separately.

Assessing real world vaccine effectiveness: A review of Scotland's approach to monitoring human papillomavirus (HPV) vaccine impact on HPV infection and cervical disease.

High-risk human papillomavirus (HPV) infections can progress to cervical cancer which is the fourth most common cancer in women globally. In Scotland, the incidence of cervical cancer has a strong socioeconomic deprivation gradient disproportionately affecting women from more deprived areas. An HPV vaccination programme was initiated in Scotland in 2008 targeting girls aged 12-13 years with a catch-up campaign running for the first three years for girls aged up to 18 years. The programme has evolved over the last 16 years with changes in the type of vaccine, dosing schedules and the extension of the programme to boys and gay, bisexual and other men who have sex with men. Vaccine uptake in Scotland has historically been high but has gradually decreased over time and disparities exist in women from more deprived areas of Scotland. The ability to link national immunisation and screening databases in Scotland has allowed direct monitoring of the impact of the HPV vaccine on virological and histological outcomes. Analyses of this linked data have demonstrated real-world evidence of high vaccine effectiveness against HPV infection, cervical disease, and cervical cancer with evidence of herd immunity in unvaccinated women. Continued monitoring is crucial to assess the duration of protection, the impact of vaccine and dosing schedules changes and the emergence of potential type replacement. With the World Health Organisation's aim to eliminate cervical cancer as a public health problem by the next century addressing the inequalities in cervical cancer incidence will be crucial. This will require targeted interventions for women most at risk of cervical cancer to ensure elimination is achieved timely for all women in Scotland.

Metaproteomic analysis from cervical biopsies and cytologies identifies proteinaceous biomarkers representing both human and microbial species.

The detection of HPV infection and microbial colonization in cervical lesions is currently done through PCR-based viral or bacterial DNA amplification. Our objective was to develop a methodology to expand the metaproteomic landscape of cervical disease and determine if protein biomarkers from both human and microbes could be detected in distinct cervical samples. This would lead to the development of multi-species proteomics, which includes protein-based lateral flow diagnostics that can define patterns of microbes and/or human proteins relevant to disease status. In this study, we collected both non-frozen tissue biopsy and exfoliative non-fixed cytology samples to assess the consistency of detecting human proteomic signatures between the cytology and biopsy samples. Our results show that proteomics using biopsies or cytologies can detect both human and microbial organisms. Across patients, Lumican and Galectin-1 were most highly expressed human proteins in the tissue biopsy, whilst IL-36 and IL-1RA were most highly expressed human proteins in the cytology. We also used mass spectrometry to assess microbial proteomes known to reside based on prior 16S rRNA gene signatures. Lactobacillus spp. was the most highly expressed proteome in patient samples and specific abundant Lactobacillus proteins were identified. These methodological approaches can be used in future metaproteomic clinical studies to interrogate the vaginal human and microbiome structure and metabolic diversity in cytologies or biopsies from the same patients who have pre-invasive cervical intraepithelial neoplasia, invasive cervical cancer, as well as in healthy controls to assess how human and pathogenic proteins may correlate with disease presence and severity.

Integrity of RNA in long-term-stored cervical liquid-based cytology samples: implications for biomarker research.

Biobanks of cervical screening (LBC) samples annotated with disease status are an invaluable resource to support the development of tools for the risk stratification of disease. Although there is growing interest in the assessment of RNA-based biomarkers, little is known on the suitability and durability of stored clinical samples (commonly used in cervical screening) to support RNA-based research. RNA was extracted from 260 stored LBC samples. Storage at -80°C or -25°C allowed isolation of sufficient RNA for further analysis. RNA was found to be substantially degraded according to Agilent Bioanalyser data. Despite this, RT-qPCR was successful in 95% samples tested. These data suggest that biobanked LBC samples are suitable for RNA-based assessment even if stored for up to 14 years.

RNA was extracted from 260 cervical screening samples stored at either -80 or -25°C. An Agilent Bioanalyser was used to examine the level of degradation of a convenience sample of RNAs. Reverse transcriptase quantitative PCR (RT-qPCR) was used to quantify levels of two cellular mRNAs in all samples as a practical means of assessing suitability of the samples for mRNA biomarker analysis.

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

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

2023 global inventory of commercial molecular tests for human papillomaviruses (HPV).

To suit the needs of the human papillomaviruses (HPV) community comprehensively, a range of commercial HPV tests with different performance characteristics are required. Four periodic inventories of commercial HPV molecular tests present in the global market were published previously in 2010, 2012, 2015 and 2020. For the fifth inventory, data were retrieved from internal files and a detailed search using the main bibliographic databases as well as general internet search without period or language restrictions was performed in December 2023. At least 264 distinct HPV tests (and 511 test variants) were available globally in December 2023. A small 2020-2023 net increase in total numbers was observed, but with a strong introduction/withdrawal dynamic: 86 new distinct HPV tests (and 141 variants) were introduced and 76 tests (and 55 variants) were withdrawn from the market in the last four years. Although quality improvement of some tests was recorded, half of all HPV tests are still without a single peer-reviewed publication, and 79 % of tests are without published evidence that demonstrate performance characteristics are in line with requirements agreed in the HPV community. Only a relatively small pool of tests fulfill the operational/performance characteristics required to meet the global cervical cancer screening challenge. Although clinical and analytical performance characteristics of many commercial HPV tests are largely unknown, such tests are used worldwide in daily clinical practice and research, with potentially deleterious consequences. Due to this long-lasting unfavorable situation, significant scope for improvement persists for both manufacturers of HPV tests and the HPV community.

Human papillomavirus negative high grade cervical lesions and cancers: Suggested guidance for HPV testing quality assurance.

BACKGROUND: Some high-grade cervical lesions and cervical cancers (HSIL+) test negative for human papillomavirus (HPV). The HPV-negative fraction varies between 0.03 % and 15 % between different laboratories. Monitoring and extended re-analysis of HPV-negative HSIL+ could thus be helpful to monitor performance of HPV testing services. We aimed to a) provide a real-life example of a quality assurance (QA) program based on re-analysis of HPV-negative HSIL+ and b) develop international guidance for QA of HPV testing services based on standardized identification of apparently HPV-negative HSIL+ and extended re-analysis, either by the primary laboratory or by a national HPV reference laboratory (NRL). METHODS: There were 116 initially HPV-negative cervical specimens (31 histopathology specimens and 85 liquid-based cytology samples) sent to the Swedish HPV Reference Laboratory for re-testing. Based on the results, an international QA guidance was developed through an iterative consensus process. RESULT: Standard PCR testing detected HPV in 55.2 % (64/116) of initially "HPV-negative" samples. Whole genome sequencing of PCR-negative samples identified HPV in an additional 7 samples (overall 61.2 % HPV positivity). Reasons for failure to detect HPV in an HSIL+ lesion are listed and guidance to identify cases for extended re-testing, including which information should be included when referring samples to an NRL are presented. CONCLUSION: Monitoring the proportion of and reasons for failure to detect HPV in HSIL+ will help support high performance and quality improvement of HPV testing services. We encourage implementation of QA strategies based on re-analysis of "HPV negative" HSIL+ samples.

Allplex HPV HR Detection assay fulfils all clinical performance and reproducibility validation requirements for primary cervical cancer screening.

Human papillomavirus (HPV)-based screening offers better protection against cervical cancer compared to cytology, but HPV screening assays must adhere to validation requirements of the international guidelines to ensure optimal performance. Allplex HPV HR Detection (Allplex) assay, launched in the late 2022, is a fully automated real-time PCR-based assay utilizing innovative technology that enables quantification and concurrent distinction of 14 high-risk HPV genotypes (HPV16,18,31,33,35,39,45,51,52,56,58,59,66 and 68). We assessed the validity of the Allplex for cervical cancer screening purposes, via comparison to a clinically validated comparator assay (Hybrid Capture 2; HC2), and through assessment of intra-laboratory reproducibility and inter-laboratory agreement. A clinical validation panel comprised of 973 residual ThinPrep samples was obtained from women aged 30-64 years participating in the organized Slovenian screening program, of these 863 were from women undergoing their regular screening visit after a previous negative screen test while 110 were from women with underlying cervical intraepithelial neoplasia grade 2 or worse (CIN2+) lesions. The Allplex's relative clinical sensitivity for detection of CIN2+ and CIN3+ were 1.01 (95%CI;0.98-1.04) and 0.98 (95%CI;0.95-1.02), compared to that of HC2. At recommended thresholds of ≥98% and ≥90%, the Allplex's clinical sensitivity and specificity (p=0.0004 and p=0.02, respectively) were non-inferior to HC2. High intra-laboratory reproducibility and inter-laboratory agreement, both overall (98.1% and 97.9%, respectively) and at genotype level (>98.7%) was observed. In addition, analytical genotype-specific performance of Allplex was compared to that of its predecessor Anyplex HPV HR; high overall agreement was observed (96.3%; kappa value 0.88), with some variations in performance. In conclusion, Allplex met all validation criteria described in the international guidelines on sensitivity, specificity and laboratory reproducibility and can be considered clinically validated for primary cervical cancer screening.

Invasive cervical cancer incidence following bivalent human papillomavirus vaccination: a population-based observational study of age at immunization, dose, and deprivation.

BACKGROUND: High-risk human papillomavirus causes cervical cancer. Vaccines have been developed that significantly reduce the incidence of preinvasive and invasive disease. This population-based observational study used linked screening, immunization, and cancer registry data from Scotland to assess the influence of age, number of doses, and deprivation on the incidence of invasive disease following administration of the bivalent vaccine. METHODS: Data for women born between January 1, 1988, and June 5, 1996, were extracted from the Scottish cervical cancer screening system in July 2020 and linked to cancer registry, immunization, and deprivation data. Incidence of invasive cervical cancer per 100 000 person-years and vaccine effectiveness were correlated with vaccination status, age at vaccination, and deprivation; Kaplan Meier curves were calculated. RESULTS: No cases of invasive cancer were recorded in women immunized at 12 or 13 years of age irrespective of the number of doses. Women vaccinated at 14 to 22 years of age and given 3 doses of the bivalent vaccine showed a significant reduction in incidence compared with all unvaccinated women (3.2/100 000 [95% confidence interval (CI) = 2.1 to 4.6] vs 8.4 [95% CI = 7.2 to 9.6]). Unadjusted incidence was significantly higher in women from most deprived (Scottish Index of Multiple Deprivation 1) than least deprived (Scottish Index of Multiple Deprivation 5) areas (10.1/100 000 [95% CI = 7.8 to 12.8] vs 3.9 [95% CI = 2.6 to 5.7]). Women from the most deprived areas showed a significant reduction in incidence following 3 doses of vaccine (13.1/100 000 [95% CI = 9.95 to 16.9] vs 2.29 [95% CI = 0.62 to 5.86]). CONCLUSION: Our findings confirm that the bivalent vaccine prevents the development of invasive cervical cancer and that even 1 or 2 doses 1 month apart confer benefit if given at 12-13 years of age. At older ages, 3 doses are required for statistically significant vaccine effectiveness. Women from more deprived areas benefit more from vaccination than those from less deprived areas.

Staged design recommendations for validating relative sensitivity of self-sample human papillomavirus tests for cervical screening.

OBJECTIVES: To ensure that the emerging methods for human papillomavirus (HPV) testing on self-collected samples in cervical screening are evaluated robustly. STUDY DESIGN AND SETTING: We assess paired study designs for relative sensitivity of self-collected vs. traditional clinician-collected samples in detection of high-grade cervical intraepithelial neoplasia. RESULTS: Designs considered are (D1) both samples at screening, with clinical actions triggered by HPV positivity; (D2) offering a self-sample test to clinician-collected HPV-positive women; (D3) as D2 but using a repeat clinician-sample as comparator; (D4) offering a choice of self- vs. clinician-sampling, and the alternative test in HPV-positive women; (D5) paired samples at referral appointment. D1 is simple to analyze but requires the largest sample size and referral of self-sample positive, clinician-sample negative women. D2 requires a much smaller sample size, and no change to clinical practice, and could be used to rule-in a test because estimates are conservative (against self-sampling). D3 mitigates this bias but requires a second clinician sample. D4 is only manageable where self-sampling already occurs. The liberal D5 might be used to rule-out a self-sampling test. CONCLUSION: A universal recommendation for an optimal study design is challenging. Staged validation might be useful with D5 as a gatekeeper for D1-D4.

Clinical performance of the novel full-genotyping OncoPredict HPV Quantitative Typing assay using the VALGENT framework.

Clinical validation of human papillomavirus (HPV) assays according to international criteria is prerequisite for their implementation in cervical cancer screening. OncoPredict HPV Quantitative Typing (QT) assay (Hiantis Srl, Milan, Italy) is a novel full-genotyping multiplex real-time PCR quantitative assay targeting E6/E7 genes, allowing individual viral load determination of 12 high-risk (HR) HPV types. Quality controls for sample adequacy, efficiency of nucleic acid extraction and PCR inhibition are included in the assay. Clinical performance of OncoPredict HPV QT test was assessed as part of the "Validation of HPV Genotyping Tests" (VALGENT-2) framework, consisting of 1300 cervical liquid-based cytology (LBC) samples of women aged between 20 and 60 years who had originally attended for routine cervical screening in Scotland. The clinical accuracy of the OncoPredict HPV QT (index test) for the detection of CIN2+ was assessed relative to the GP5+/6+ Enzyme ImmunoAssay (GP5+/6+ EIA) (comparator test), using noninferiority criteria. Intra- and interlaboratory reproducibility of the assay was assessed on a subpopulation, comprising 526 samples. The relative sensitivity and specificity for OncoPredict HPV QT vs GP5+/6+-PCR-EIA were 1.01 (95% CI: 0.99-1.03) and 1.03 (95% CI: 1.0-1.06) respectively. The P-values for noninferiority were ≤0.001. The intra- and inter-laboratory reproducibility demonstrated a high concordance (>98.7%) with kappas for individual types ranging from 0.66 to 1.00. OncoPredict HPV QT fulfills the international validation criteria for the use of HPV tests in cervical cancer screening.

The changing nature of HPV associated with high grade cervical lesions in vaccinated populations, a retrospective study of over 1700 cases in Scotland.

BACKGROUND: Understanding the pattern and dominance of HPV types in high grade cervical disease within increasingly vaccinated populations will help inform the development of appropriate screening and management protocols. METHODS: Over 1700 cases of cervical intraepithelial neoplasia (CIN) diagnosed between 2011 and 2017 in women younger than 25 were genotyped for HPV. Logistic regression was used to assess the association between HPV 16/18 positivity with biopsy-collection year, birth year, deprivation and vaccination status. Regression analysis was repeated for cross-protective types (31, 33 and 45). Type specific detail of non-vaccine types by vaccination status was presented descriptively. RESULTS: Detection of HPV 16/18 or 16/18/31/33 and 45 was lower in CIN2 associated with full vaccination vs no vaccination (OR 0.3; 95% CI 0.2-0.5 & 0.4; 95% CI 0.3-0.6 respectively) Similar observations were made for CIN3. The relative contribution of non-established high-risk types including those considered low risk was greater among vaccinated women with CIN2+ vs unvaccinated women with CIN2+. CONCLUSIONS: The change in HPV distribution in CIN2+ in vaccinated populations is a further marker of vaccine impact. Additionally, the progression rate of CIN2+ in vaccinated populations may be lower given the shift in type distribution. The definition of high grade disease in vaccinated populations may warrant reassessment.

Testing for Human Papillomaviruses in Urine, Blood, and Oral Specimens: an Update for the Laboratory.

Twelve high-risk alpha human papillomavirus (HPV) genotypes cause approximately 690,000 cancer cases annually, with cervical and oropharyngeal cancer being the two most prominent types. HPV testing is performed in laboratory settings for various applications of a clinical, epidemiological, and research nature using a range of clinical specimens collected by clinicians or by individuals (self-collected specimens). Here, we reflect on the importance and justification of using the right test for the right application and provide practical updates for laboratories either participating in or anticipating involvement in HPV testing in three specimen types, namely, urine, blood, and oral specimens, which are considered "alternative" specimens by many. In addition to clinician-collected cervical samples and self-collected cervicovaginal samples, first-void urine is emerging as a credible specimen for HPV-based cervical cancer screening, triage of HPV screen-positive women, monitoring HPV vaccine impact, and HPV testing in groups for which a less invasive sample is preferred. Detection of cell-free DNA (including HPV DNA) in blood has great promise for the early detection of HPV-attributable oropharyngeal cancer (HPV-AOC) and potentially other HPV-driven cancers and as an adjunct prognostic marker in long-term tumor surveillance, including treatment response. The moderate sensitivity of HPV testing in oral rinses or swabs at HPV-AOC diagnosis prevents its use in HPV-AOC secondary prevention but represents a promising prognostic tool in HPV-AOC tertiary prevention, where the HPV persistence in oral rinses throughout treatment may predict early HPV-AOC recurrences and/or the development of secondary HPV-AOC. The increasing sophistication of specific collection devices designed for alternative samples and the enhanced precision of novel molecular technologies are likely to support the evolution of this field and catalyze potential translation into routine practice.

The role of circulating viral and tumour DNA in the diagnosis and management of HPV associated anogenital cancers, a systematic review and meta-analysis.

BACKGROUND: Human papillomavirus associated anogenital cancers are a significant global burden. The detection of biomarkers (circulating tumour DNA; ctDNA or circulating HPV DNA; cHPV DNA) in blood referred to as "liquid biopsy" may support the early diagnosis and monitoring of affected individuals. METHODS: A systematic review, including meta-analysis of studies available in the literature on the utilization of ctDNA and cHPV DNA as diagnostic, predictive, and monitoring biomarker tests of HPV associated anogenital cancers was performed following the criteria of PRISMA. RESULTS: A total of 31 studies were eligible for systematic review; 20 used cHPV DNA in cervical cancers; 7 used ctDNA in cervical cancer; 5 used cHPV DNA in anal cancer; no eligible studies on vulva, vaginal or penile cancer were available. The meta-analysis identified low sensitivity (0.36) and high specificity (0.96) of cHPV DNA as diagnostic for cervical cancer. Comparatively, there was high sensitivity (0.95) and specificity (1.0) of cHPV DNA for the diagnosis of anal cancer. cHPV DNA and/or ctDNA in cervical cancer were prognostic markers associated with poor clinical outcomes. Additionally, in anal cancer the post treatment detection of cHPV DNA was informative in the prediction of treatment response or progression-free survival. CONCLUSION: ctDNA and cHPV DNA are promising diagnostic and prognostic biomarkers for the detection of anogenital disease. Evolution and refinement of molecular tools is likely to improve performance further. Additionally the comparative absence of studies in the vulval, vaginal and penile context warrants further exploration and research.

Diversity of cervicovaginal human papillomavirus (HPV) genotypes and naturally occurring E6/E7 DNA polymorphisms of HPV-16 in Ghana.

Human papillomavirus (HPV) E6 and E7 oncogene expression is essential for cervical carcinogenesis. Evidence exists that E6/E7 variants may have different transforming activities while the risk of HPV-16 variants (A/D) differs by race/ethnicity. We determined the type-specific diversity of HPV infection in women with high grade cervical disease or cervical cancer in Ghana and investigated naturally occurring E6/E7 DNA variants in this population. HPV genotyping was carried out on 207 cervical swab samples collected from women referred to a gynaecology clinic at two teaching hospitals in Ghana. HPV-16, HPV-18 and HPV-45 were detected in 41.9%, 23.3% and 16.3% of cases respectively. HPV-16 E6/E7 DNA sequencing was performed in 36 samples. Thirty samples contained E6/E7 variants of the HPV-16-B/C lineage. 21/36 samples were of the HPV-16C1 sublineage variant and all contained the E7 A647G(N29S) single nucleotide polymorphism (SNP). This study reveals the diversity of E6/E7 DNA and the dominance of HPV16 B/C variants in cervicovaginal HPV infection in Ghana. Type-specific HPV diversity analysis indicates that most Ghanaian cervical disease cases are vaccine preventable. The study provides an important baseline from which for the impact of vaccine and antivirals on clinically relevant HPV infection and associated disease can be measured.

Quality assurance in human papillomavirus testing for primary cervical screening.

The recommendation for cervical screening is that it should be based on human papillomavirus (HPV) molecular testing. For all screening programs, attention to quality assurance is required to fully realize the benefits. Internationally recognized quality assurance recommendations for HPV-based screening are needed that are ideally applicable for a variety of settings, including in low- and middle-income countries. We summarize the main points of quality assurance for HPV screening, with a focus on the selection, implementation, and use of an HPV screening test, quality assurance systems (including internal quality control and external quality assessment), and staff competence. While we recognize that it might not be possible to fulfill all points in all settings, an awareness of the issues is essential.