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.     

Experience with high-risk human papillomavirus testing on vaginal brush-based self-samples of non-attendees of the cervical screening program

We evaluated the effect of offering brush-based vaginal self-sampling for high-risk human papillomavirus (hrHPV) testing to non-attendees of the cervical screening program on response rate, compliance to follow-up and cervical intraepithelial neoplasia grade 2 or 3 (CIN2+/CIN3+) yield. In addition, concordance of hrHPV test results between physician-taken cervical scrapes and vaginal self-samples was determined. A total of 26,409 nonattending women were randomly assigned to receive a vaginal brush device for hrHPV testing by Hybrid Capture-2 method (i.e., self-sampling group, n = 26,145) or a reinvitation for regular cytology-based screening (i.e., recall control group, n = 264). hrHPV-positive self-sampling responders were invited for a physician-taken scrape for cytology and blinded hrHPV testing. If cytology was abnormal, women were referred for colposcopy. Response rate in the self-sampling group was significantly increased compared to the recall control group (30.8% versus 6.5%; p < 0.001). The concordance rate between hrHPV detection in self-samples and corresponding physician-taken cervical scrape samples was 68.8%. Amongst women with CIN3+ and CIN2+, the concordance rates in hrHPV positivity between both samples were 95.5% and 93.8%, respectively. Adherence at baseline to cytology triage of hrHPV-positive self-sampling women (89.1%) and colposcopy referral of those with abnormal cytology (95.8%) was high. The CIN2+/CIN3+/carcinoma yields were 1.5%, 1.0% and 0.1%, respectively, in self-sampling responders. In conclusion, offering hrHPV testing on self-sampled vaginal material with a brush device to non-attendees significantly increases the attendance to the regular screening program, yields hrHPV test results that are in very good concordance with those of physician-taken scrapes in women with CIN2+/CIN3+, and is effective in detecting CIN2+/CIN3+.     

Comparison of human papillomavirus genotyping and cytology triage,COMPACT Study: Design,methods and baseline results in 14 642 women

Although cytology‐based screening programs have significantly reduced mortality and morbidity from cervical cancer, the global consensus is that primary human papillomavirus (HPV) testing for cervical screening increases detection of high‐grade cervical intraepithelial neoplasia (CIN) and invasive cancer. However, the optimal triage strategy for HPV‐positive women to avoid over‐referral to colposcopy may be setting specific. As Japan requires data that have been generated domestically to modify screening guidelines, we conducted a 3‐year prospective study, COMparison of HPV genotyping And Cytology Triage (COMPACT), to evaluate the potential role of HPV16/18 partial genotyping and cytology for primary HPV screening. In total, 14 642 women aged 20 to 69 years undergoing routine screening at 3 centers in Hokkaido were enrolled. Conventional cytology and HPV testing were carried out. Women with abnormal cytology or HPV16/18 positivity underwent colposcopy. Those with 12 other high‐risk (hr) HPV types underwent repeat cytology after 6 months. Primary study endpoints were detection of high‐grade cervical disease defined as CIN2/CIN3 or greater as determined by consensus pathology. Prevalence of cytological abnormalities was 2.4%. hrHPV, HPV 16, and HPV 18 were detected in 4.6%, 0.9%, and 0.3% of women, respectively. HPV16/18 were detected in all (8/8) invasive cervical cancers and in all (2/2) adenocarcinomas in situ. Both cytological abnormalities and hrHPV positivity declined with increasing age. This is the first Japanese study to investigate the role of partial genotyping and cytology in an HPV‐based screening program. Results should help policy‐makers develop guidelines for future cervical screening programs and management of cervical abnormalities based on HPV genotype.     

Evaluation of cervical screening strategies with adjunct high-risk human papillomavirus testing for women with borderline or mild dyskaryosis

The management of women with a smear read as borderline/mild dyskaryosis (BMD) found by cervical cancer screening is still under discussion as only few of these cases are associated with high-grade lesions. To determine the optimal screening strategy for these women, a simulation model of cervical cancer development was used that is based on high-risk human papillomavirus (hrHPV) infection. The current strategy of repeat cytological testing at 6 and 18 months after BMD was compared to strategies with adjunct hrHPV testing. Calculations were done for both conventional and liquid-based cytology as the primary screening tool. In comparison to current screening, adjunct hrHPV testing was more effective in preventing cancer and more woman-friendly (reduction in colposcopy referrals with outcome < cervical intraepithelial neoplasia (CIN2) of up to 56% and in repeat smears of 30-100%). In combination with conventional cytology, cost-effective strategies were the ones in which a sample for high-risk human papillomavirus (hrHPV) testing is collected at a return visit within 1 month or in which hrHPV testing is restricted to repeat smears taken at 6 and 18 months. For these strategies, co-collection of samples for hrHPV testing at baseline is not necessary which has organizational and cost advantages. In combination with liquid-based cytology, it was cost-effective to perform a reflex hrHPV test at baseline from the liquid-based specimen. Liquid-based screening was more effective than conventional screening, but annual diagnosis costs were euro5 million higher (population size 16 million). In conclusion, our calculations indicate that implementation of hrHPV testing for the management of women with borderline or mild dyskaryosis (BMD) is feasible both in settings where conventional and liquid-based cytology is current practice.     

Comparison of Hybrid capture 2 testing at different thresholds with cytology as primary cervical screening test

Background:

We evaluated the performance of primary high-risk human papillomavirus (hrHPV) testing by hybrid capture 2 (HC2) with different thresholds for positivity, in comparison with conventional cytology.

Methods:

We used data of 25 871 women (aged 30–60 years) from the intervention group of the VUSA-Screen study (VU University Medical Center and Saltro laboratory population-based cervical screening study), who were screened by cytology and hrHPV. Primary outcome measure was the number of cervical intraepithelial neoplasia grade 3 or higher (CIN3+), detected within 3 years. We compared baseline cytology testing with three possible hrHPV screening strategies at different relative light unit/cutoff (RLU/CO) thresholds.

Results:

Compared with baseline cytology testing, hrHPV DNA testing as a sole primary screening instrument did not yield a superior sensitivity, as well as lower colposcopy referral rate and lower false positivity rate at any RLU/CO threshold. The hrHPV screening at 1 RLU/CO threshold with cytology triage at baseline and at 12 months revealed the highest sensitivity for CIN3+ (relative sensitivity of 1.32), although still displaying a lower colposcopy referral rate than cytology testing (relative colposcopy rate of 0.94). Higher thresholds (>1RLU/CO) yielded lower colposcopy rates, but resulted in substantial loss in sensitivity.

Conclusions:

The hrHPV testing at the commonly used threshold of 1 RLU/CO with cytology triage at baseline and at 12 months showed a much higher sensitivity with a lower colposcopy referral rate compared with cytology testing.     

Effectiveness of two strategies to follow-up ASC-US and LSIL screening results in The Netherlands using repeat cytology with or without additional hrHPV testing: a retrospective cohort study

Purpose

The purpose of the study was to assess the effectiveness of repeat cytology with and without additional high-risk human papilloma virus (hrHPV) testing after atypical squamous cells of undetermined significance/low-grade squamous intraepithelial lesion (ASC-US/LSIL) screening results.

Methods

In the Netherlands, ASC-US/LSIL is triaged by repeat cytology at 6 months or repeat cytology at 6 months with additional hrHPV testing. ASC-US/LSIL results from 13,734 screenees in 2008 were extracted from “Dutch Pathology Registry” including cytology, histology, and/or HPV follow-up results. Proportions of compliance, repeat cytology, referral, and detected cervical intraepithelial neoplasia (CIN) were assessed.

Results

With additional hrHPV testing, 46.8 % was send back to regular screening at 6 months, 28.6 % needed second repeat cytology, and 24.6 % was referred for colposcopy. Without additional hrHPV testing, this was 0.0, 76.1, and 23.9 %, respectively. With additional hrHPV testing, significantly higher proportions of persisting ASC-US/LSIL; compliance with repeat/referral advices; and histological detection of CIN0 (no CIN or cancer), CIN1, and CIN2 were found but equal proportions CIN3+.

Conclusions

Additional hrHPV testing shortens follow-up without altering CIN3+ detection. Detection of CIN0, CIN1, and CIN2 was higher, presumably by hrHPV-driven biased cytology and detection bias. Restricting additional hrHPV testing to older women, reading cytology without knowledge of hrHPV status, and addition of more specific triage tests could further improve the effectiveness of additional hrHPV testing.     

The health and economic effects of HPV DNA screening in The Netherlands

We studied the health and economic effects of human papillomavirus (HPV) DNA testing in cervical screening using a simulation model. The key data source was a Dutch longitudinal screening trial. We compared cytological testing with repeat cytology (for borderline/mildly abnormal smears) to HPV testing with cytology triage (for HPV‐positive smears), combination testing (combined HPV and cytology) and cytological testing with HPV triage (for borderline/mildly abnormal smears). We varied the screening interval from 5 to 10 years. The main outcome measures were the number of cervical cancer cases, the number of quality‐adjusted life years (QALYs), and the incremental cost‐effectiveness ratio (ICER). The base‐case estimates were accompanied with ranges across 118 calibrated parameter settings (calibration criteria: cervical intraepithelial neoplasia 2/3, cancer and mortality rates). In comparison to 5‐yearly cytology, 5‐yearly HPV testing with cytology triage gave a reduction in the number of cancer cases of 23% (range, 9–27%). The reduction was 26% (range, 10–29%) for combination testing and 3% (range, ?1 to 8%) for cytology with HPV triage. For strategies with primary HPV testing, the model also estimated a reduction in cancer cases when the screening interval was extended to 7.5 years. Five‐yearly cytology with HPV triage and 5 to 7.5‐yearly HPV testing with cytology triage were cost effective for the base‐case settings and the majority of calibrated parameter settings (ICER below Dutch willingness‐to‐pay threshold of €20,000/QALY). Our model indicates that HPV testing with cytology triage is likely to be cost effective. An extension of the screening interval may be considered to control costs.     

Interlaboratory variation in the performance of liquid‐based cytology: Insights from the ATHENA trial

Although it is recognized that cervical cytology is highly subjective, and that there is considerable interlaboratory variation in how slides are evaluated, little is known as to how this impacts the performance of cytology. In the ATHENA trial, liquid‐based cytology specimens from 46,887 eligible women ≥21 years of age were evaluated at four large regional US laboratories, providing a unique opportunity to evaluate the impact of interlaboratory variations on the performance of cervical cytology. All women with abnormal cytology (atypical squamous cells of undetermined significance or higher) were referred to colposcopy, as were all high‐risk human papillomavirus (hrHPV)–positive women ≥25 years of age and a random subset of those ≥25 years of age who were negative by both hrHPV testing and cytology. Sociodemographics, risk factors for cervical disease, and prevalence of cervical intraepithelial neoplasia (CIN) were similar across the laboratories. There were considerable differences among the laboratories both in overall cytological abnormal rates, ranging from 3.8 to 9.9%, and in sensitivity of cytology to detect CIN grade 2 or worse (CIN2+), from 42.0 to 73.0%. In contrast, the hrHPV positivity rate varied only from 10.9 to 13.4%, and the sensitivity of hrHPV testing from 88.2 to 90.1%. These observations suggest that hrHPV testing without cytology should be considered as the initial method for cervical cancer screening.     

Primary cervical cancer screening with HPV testing compared with liquid-based cytology: results of round 1 of a randomised controlled trial �C the HPV FOCAL Study

Background:

Round 1 data of human papillomavirus (HPV) FOCAL, a three-arm, randomised trial, which aims to establish the efficacy of HPV DNA testing as a primary screen for cervical cancer, are presented.

Methods:

The three arms are: Control arm – liquid based cytology with atypical squamous cells of unknown significance (ASC-US) triage with hrHPV testing; Intervention Arm – hrHPV at entry with liquid-based cytology (LBC) triage of hrHPV positives, with exit screen at 4 years; Safety check arm – hrHPV at entry with LBC triage of hrHPV positives with exit screen at 2 years.

Results:

A total of 6154 women were randomised to the control arm and 12 494 to the HPV arms (intervention and safety check). In the HPV arm, the baseline cervical intraepithelial neoplasia (CIN)2+ and CIN3+ rate was 9.2/1000 (95%CI; 7.4, 10.9) and 4.8/1000 (95%CI; 3.6, 6.1), which increased to 16.1/1000 (95%CI 13.2, 18.9) for CIN2+ and to 8.0/1000 (95%CI; 5.9, 10.0) for CIN3+ after subsequent screening of HPV-DNA-positive/cytology-negative women. Detection rate in the control arm remained unchanged after subsequent screening of ASC-US-positive/hrHPV DNA-negative women at 11.0/1000 for CIN2+ and 5.0/1000 for CIN3+.

Conclusion:

After subsequent screening of women who were either hrHPV positive/cytology negative or ASC-US positive/HPV negative, women randomised to the HPV arms had increased CIN2+ detection compared with women randomised to the cytology arm.     

Population-based Cervical Cancer Screening Using Highrisk HPV DNA Test and Liquid-based Cytology in Northern Thailand

Background: Northern Thailand is a region with a high cervical cancer incidence. Combined high-risk HPV (hrHPV) DNA testing and cytology (co-testing) has increasingly gained acceptance for cervical cancer screening. However, to our knowledge, data from a population-based screening using co-testing have not been available in this region. This study therefore aimed to evaluate the performance of cytology and hrHPV test in women in northern Thailand. Materials and Methods: Cervical samples were collected for hybrid capture 2 (HC2) testingand liquid-based cytology from women aged 30 to 60 years who were residents in 3 prefectures of Chiang Mai in northern Thailand between May and September 2011. Women with positive cytology were referred to colposcopy, while women with positive for HC2 only were followed for 2 years. Results: Of 2,752 women included in this study, 3.0% were positive in both tests, 4.1% for HC2 only, and 1.3% had positive cytology only. At baseline screening, positive HC2 was observed in 70.6% among cytology-positive women compared with 4.3% amongcytology-negative women. The prevalence of positive HC2 or cytology peaked in the age group 35-39 years and was lowest in the age group 55-60 years. High-grade squamous intraepithelial lesion or worse lesions (HSIL+) were histologically detected in 23.5% of women with positive baseline cytology and in 9.8% of women with positive baseline HC2 only on follow-up. All women with histologic HSIL+ had positive baseline HC2. Conclusions: The hrHPV test is superior to cytology in the early detection of high-grade cervical epithelial lesions. In this study, the prevalence of histologic HSIL+ on follow-up of women with positive hrHPV test was rather high, and these women should be kept under careful surveillance. In northern Thailand, hrHPV testing has a potential to beused as a primary screening test for cervical cancer with cytology applied as a triage test.     

Validation of a DNA methylation HPV triage classifier in a screening sample

High‐risk human papillomavirus (hrHPV) DNA tests have excellent sensitivity for detection of cervical intraepithelial neoplasia 2 or higher (CIN2+). A drawback of hrHPV screening, however, is modest specificity. Therefore, hrHPV‐positive women might need triage to reduce adverse events and costs associated with unnecessary colposcopy. We compared the performance of HPV16/18 genotyping with a predefined DNA methylation triage test (S5) based on target regions of the human gene EPB41L3, and viral late gene regions of HPV16, HPV18, HPV31 and HPV33. Assays were run using exfoliated cervical specimens from 710 women attending routine screening, of whom 38 were diagnosed with CIN2+ within a year after triage to colposcopy based on cytology and 341 were hrHPV positive. Sensitivity and specificity of the investigated triage methods were compared by McNemar's test. At the predefined cutoff, S5 showed better sensitivity than HPV16/18 genotyping (74% vs 54%, P = 0.04) in identifying CIN2+ in hrHPV‐positive women, and similar specificity (65% vs 71%, P = 0.07). When the S5 cutoff was altered to allow equal sensitivity to that of genotyping, a significantly higher specificity of 91% was reached (P < 0.0001). Thus, a DNA methylation test for the triage of hrHPV‐positive women on original screening specimens might be a valid approach with better performance than genotyping.     

Chapter 14: Role of triage testing in cervical cancer screening

The classic model of cervical cancer prevention-primary screening with cytology, followed by diagnostic colposcopically directed biopsy, and finally treatment of cancer precursors-is undergoing dynamic change. The introduction of human papillomavirus (HPV) DNA testing and other new modalities provides more options but increases complexity in the sequence of screening, triage, diagnosis, and patient management. This chapter will focus on the role of triage and risk stratification in management. The utility of HPV testing has been established for triage of cytologic findings of atypical squamous cells of undetermined significance but not for low-grade squamous intraepithelial lesions or worse. Countries without established cytology services may consider alternative screening, triage, and treatment programs that may be more readily implemented than a resource-rich "cytology followed by colposcopy" paradigm requiring an infrastructure of highly trained personnel. The diagnostic step of colposcopy and directed biopsy is not completely sensitive in the detection of cervical intraepithelial neoplasia (CIN) 2 or 3 as is sometimes assumed. The partial insensitivity of this diagnostic step results in a population of women with negative colposcopically directed-biopsy findings but at increased risk for missed prevalent disease: these women may require additional triage rather than resumption of routine screening. As more efficient screening, triage, and diagnosis increase the sensitivity of detection of even very small CIN2 or CIN3, overtreatment of lesions that might otherwise regress becomes a concern and highlights the need to identify accurate markers of risk of progression to cancer. Markers of molecular events further along the pathway from HPV infection to development of cancer may ultimately provide more specificity in triage and diagnosis.     

The clinical value of HPV genotyping in triage of women with high‐risk‐HPV‐positive self‐samples

Cytology alone, or combined with HPV16/18 genotyping, might be an acceptable method for triage in hrHPV‐cervical cancer screening. Previously studied HPV‐genotype based triage algorithms are based on cytology performed without knowledge of hrHPV status. The aim of this study was to explore the value of hrHPV genotyping combined with cytology as triage tool for hrHPV‐positive women. 520 hrHPV‐positive women were included from a randomised controlled self‐sampling trial on screening non‐attendees (PROHTECT‐3B). Eighteen baseline triage strategies were evaluated for cytology and hrHPV genotyping (Roche Cobas 4800) on physician‐sampled triage material. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), referral rate, and number of referrals needed to diagnose (NRND) were calculated for CIN2+ and CIN3+. A triage strategy was considered acceptable if the NPV for CIN3+ was ≥98%, combined with maintenance or improvement of sensitivity and an increase in specificity in reference to the comparator, being cytology with a threshold of atypical cells of undetermined significance (ASC‐US). Three triage strategies met the criteria: HPV16+ and/or ≥LSIL; HPV16+ and/or ≥HSIL; (HPV16+ and/or HPV18+) and/or ≥HSIL. Combining HPV16+ and/or ≥HSIL yielded the highest specificity (74.9%, 95% CI 70.5–78.9), with a sensitivity (94.4%, 95% CI 89.0–97.7) similar to the comparator (93.5%, 95% CI 87.7–97.1), and a decrease in referral rate from 52.2% to 39.5%. In case of prior knowledge of hrHPV presence, triage by cytology testing can be improved by adjusting its threshold, and combining it with HPV16/18 genotyping. These strategies improve the referral rate and specificity for detecting CIN3+ lesions, while maintaining adequate sensitivity.     

Combined CADM1 and MAL promoter methylation analysis to detect (pre-)malignant cervical lesions in high-risk HPV-positive women

Given the lower specificity for high-grade cervical lesions of high-risk human papillomavirus (hrHPV) testing compared to cytology, additional triage testing for hrHPV test-positive women is needed to detect high-grade cervical lesions. Here, we tested whether combined methylation analysis for cell adhesion molecule 1 (CADM1) and T-lymphocyte maturation associated protein (MAL), both functionally involved in cervical carcinogenesis, could serve as such a triage marker. Four quantitative methylation-specific PCRs (qMSP), two for CADM1 (regions M12 and M18) and MAL (regions M1 and M2) each, were applied to 261 cervical tissue specimens ranging from no neoplasia to carcinoma. When qMSPs were combined and positivity for at least one of the qMSPs in the combination was taken into account, the highest positivity rates for cervical intraepithelial neoplasia grade 3 (CIN3) lesions (97%) and squamous cell- and adeno-carcinomas (99%) were obtained by combining a single CADM1 marker with a single MAL marker. Subsequent qMSP analysis of 70 GP5+/6+-PCR hrHPV-positive scrapings revealed that a two-marker panel consisting of CADM1-M18 and MAL-M1 was most discriminative, detecting 90% of women with CIN3 (n = 30), whereas it showed a positive result in only 13.5% of women without cervical disease (n = 40). Finally, we applied hrHPV GP5+/6+-PCR testing followed by CADM1-M18/MAL-M1 methylation analysis to a cohort of 79 women visiting the outpatient colposcopy clinic. hrHPV testing revealed a sensitivity of 97% and a specificity of 33% for CIN3+. Additional CADM1-M18/MAL-M1 methylation analysis on the hrHPV-positive women increased the specificity to 78% with a sensitivity of 70%. In conclusion, the methylation marker panel CADM1-M18 and MAL-M1 may serve as an alternative molecular triage tool for hrHPV-positive women.     

Evaluation of 14 triage strategies for HPV DNA-positive women in population-based cervical screening

High-risk human papillomavirus (hrHPV) testing has a higher sensitivity but lower specificity than cytology for detection of high-grade intraepithelial neoplasia (CIN). To avoid over-referral to colposcopy and overtreatment, hrHPV-positive women require triage testing and/or followup. A total of 25,658 women (30-60 years) enrolled in a population-based cohort study had an adequate baseline Pap smear and hrHPV test. The end-point was cumulative two-year risk of CIN grade 3 or worse (CIN3+). In a post-hoc analysis, fourteen triage/followup strategies for hrHPV-positive women (n = 1,303) were evaluated for colposcopy referral rate, positive (PPV) and negative predictive value (NPV). Five strategies involved triage testing without a repeat test and nine strategies involved triage testing followed by one repeat testing. The tests were cytology, hrHPV, HPV16/18 genotyping and HPV16/18/31/33/45 genotyping. Results were adjusted for women in the cohort study who did not attend repeat testing. Of the strategies without repeat testing, combined cytology and HPV16/18/31/33/45 genotyping gave the highest NPV of 98.9% (95%CI 97.6-99.5%). The corresponding colposcopy referral rate was 58.1% (95%CI 55.4-60.8%). Eight of the nine strategies with retesting had an estimated NPV of at least 98%. Of those, cytology triage followed by cytology at 12 months had a markedly lower colposcopy referral rate of 33.4% (95%CI 30.2-36.7%) than the other strategies. The NPV of the latter strategy was 99.3% (95%CI 98.1-99.8%). Triage hrHPV-positive women with cytology, followed by repeat cytology testing yielded a high NPV and modest colposcopy referral rate and appear to be the most feasible management strategy.     

Human papillomavirus as a target for management,prevention and therapy

The discovery that human papillomavirus (HPV) is the necessary causal factor in cervical carcinogenesis has made it a target for prophylactic and therapeutic vaccines, as well as a diagnostic tool in cervical screening. Whilst prophylactic vaccination has proven very effective in terms of preventing cervical cancer precursor lesions, therapeutic strategies have presented far greater challenges. HPV testing has shown itself to be extremely valuable in the triage of low grade cytological abnormalities, test of cure following treatment of cervical intraepithelial neoplasia (CIN), and will, over the next 10 years, gradually replace cytology as the mainstay of primary cervical screening. In this review, the latest evidence supporting HPV as both a biomarker of risk for cervical cancer and a target for prophylactic and therapeutic vaccination is presented.     

Prevalence of types 16 and 33 is increased in high-risk human papillomavirus positive women with cervical intraepithelial neoplasia grade 2 or worse

High-risk human papillomavirus (hrHPV) types are causally related to cervical cancer and its high-grade precursor lesions. The risk posed by the different hrHPV types for the development of cervical intraepithelial neoplasia grade 2 or worse (> or =CIN2) needs to be established. Here, we present the hrHPV type-distribution in relation to cytology and histology for women participating in a cervical screening program. From 44,102 women who participated in a population-based cervical screening program in the Netherlands, 2,154 hrHPV GP5+/6+ PCR positive women were recruited to determine the distribution of 14 hrHPV types by reverse line blotting of GP5+/6+ PCR products. For each HPV type, associations with cytology and histologically confirmed > or =CIN2 were measured by odds ratios. HPV types 16 and 33 were more prevalent in women, amongst those containing a single hrHPV type, with moderate dyskaryosis or worse (>BMD) than in women with normal cytology, but only in case of underlying > or =CIN2 (OR 4.10, 95%CI 2.98-5.64 and OR 2.68, 95%CI 1.39-5.15, respectively). Similar results were obtained for women with double infections (OR 3.29, 95% CI 1.61-6.75 and OR 4.37, 95% CI 1.17-16.34). Coexisting types did not influence the prevalence of > or =CIN2 in HPV 16 or 33 positive women. The increased prevalence of type 16 and 33 in hrHPV positive women with > or =CIN2, compared to women with normal cytology, suggests that infection with these types confers an increased risk for development of > or =CIN2. Distinguishing these types may therefore have implications for future cervical screening strategies.     

Routine cervical screening with primary HPV testing and cytology triage protocol in a randomised setting

The role of high-risk human papillomavirus (hrHPV) testing in primary cervical screening has not been established. We generated a randomised evaluation design ultimately to clarify whether primary hrHPV testing implemented into routine screening can bring increase in the programme effectiveness. The aim of the present report on first-year results was to assess the cross-sectional relative validity parameters for routine hrHPV screening, in comparison with conventional screening. An equal number of women invited to routine screening was randomly allocated to primary hrHPV screening (n=7060) and to cytological screening (n=7089). In the hrHPV screening arm, after a single positive hrHPV test result, the need of colposcopy referral was determined by a cytological triage test. Compared with the conventional arm, more colposcopy referrals were made in the hrHPV screening arm (relative risk 1.51, confidence interval 95% 1.03-2.22). Specificity of the primary screening with sole hrHPV test (91.5-92.1%) was much lower than that with the cytology triage (98.7-99.3%), which was not quite as specific as screening with conventional cytology (99.2-99.6%). Compared with conventional cytology, primary screening with hrHPV test results in increased cross-sectional relative sensitivity at the level of all positive lesions at the cost of substantial loss in specificity. With cytology triage, the specificity improves to the level of conventional cytology.     

Triage of high-risk HPV positive women in cervical cancer screening

Introduction: High-risk human papillomavirus (hrHPV) testing is expected to replace cytology as primary screening method for cervical cancer screening in an increasing number of countries. The high sensitivity of hrHPV testing is combined with a limited specificity which makes triaging of hrHPV positive women necessary. As an ideal triage method does not yet exist, an optimal triage strategy for hrHPV positive women based on current knowledge should be obtained. The aim of this article is to present an overview of available options for triage of hrHPV positive women, with their strengths and limitations and possible future opportunities.

Areas covered: Current knowledge on morphological biomarkers, molecular biomarkers and combined triage strategies will be discussed to give an overview of the state-of-the-art on triaging hrHPV positive women. The literature search was limited to studies on triage strategies for hrHPV positive women.

Expert commentary: Experience with morphology-based biomarkers makes these a valuable triage method. However, they lack the ability of differentiating productive from transforming infections. Molecular biomarkers are objective, highly reproducible, can be used in high throughput testing, and show promising results. With more extensive knowledge on these molecular markers, cervical cancer screening may transform to a full molecular screening in the future.     

Comparative performance of novel self‐sampling methods in detecting high‐risk human papillomavirus in 30,130 women not attending cervical screening

We determined whether the participation rate for a brush‐based cervicovaginal self‐sampling device is noninferior to the participation rate for a lavage‐based one for testing for hrHPV (high‐risk human papillomavirus). Additionally, positivity rates for hrHPV, the detection rates for cervical intraepithelial neoplasia grades 2 and 3 or worse (CIN2+/3+), and user comfort were compared. A total of 35,477 non‐responders of the regular cervical screening program aged 33–63 years were invited to participate. Eligible women (n = 30,130) were randomly assigned to receive either a brush‐based or a lavage‐based device, and a questionnaire for reporting user convenience. Self‐sampling responders testing hrHPV‐positive were invited for a physician‐taken sample for cytology; triage‐positive women were referred for colposcopy. A total of 5,218 women participated in the brush‐based sampling group (34.6%) and 4809 women in the lavage‐based group (31.9%), i.e. an absolute difference of 2.7% (95%CI 1.8–4.2). The hrHPV‐positivity rates in the two groups were identical (8.3%, relative risk (RR) 0.99, 95%CI 0.87–1.13). The detection of CIN2+ and CIN3+ in the brush group (2.0% for CIN2+; 1.3% for CIN3+) was similar to that in the lavage group (1.9% for CIN2+; 1.0% for CIN3+) with a cumulative RR of 1.01, 95%CI 0.83–1.24 for CIN2+ and 1.25, 95%CI 0.92–1.70 for CIN3+. The two self‐sampling devices performed similarly in user comfort. In conclusion, offering a brush‐based device to non‐responders is noninferior to offering a lavage‐based device in terms of participation. The two self‐sampling methods are equally effective in detecting hrHPV, CIN2+/CIN3+ and are both well accepted.