Lesley Ashdown-Barr

Comparison of Seven Tests for High-Grade Cervical Intraepithelial Neoplasia in Women with Abnormal Smears: the Predictors 2 Study

ABSTRACT High-risk human papillomavirus (HPV) DNA/RNA testing provides higher sensitivity but lower specificity than cytology for the identification of high-grade cervical intraepithelial neoplasia (CIN). Several new HPV tests are now available for this purpose, and a direct comparison of their properties is needed. Seven tests were evaluated with samples in liquid PreservCyt transport medium from 1,099 women referred for colposcopy: the Hybrid Capture 2 (Qiagen), Cobas (Roche), PreTect HPV-Proofer (NorChip), Aptima HPV (Gen-Probe), and Abbott RealTime assays, the BD HPV test, and CINtec p16INK4a cytology (mtm laboratories) immunocytochemistry. Sensitivity, specificity, and positive predictive value (PPV) were based on the worst histology found on either the biopsy or the treatment specimen after central review. Three hundred fifty-nine women (32.7%) had CIN grade 2+ (CIN2+), with 224 (20.4%) having CIN3+. For detection of CIN2+, Hybrid Capture 2 had 96.3% sensitivity, 19.5% specificity, and 37.4% PPV. Cobas had 95.2% sensitivity, 24.0% specificity, and 37.6% PPV. The BD HPV test had 95.0% sensitivity, 24.2% specificity, and 37.8% PPV. Abbott RealTime had 93.3% sensitivity, 27.3% specificity, and 38.2% PPV. Aptima had 95.3% sensitivity, 28.8% specificity, and 39.3% PPV. PreTect HPV-Proofer had 74.1% sensitivity, 70.8% specificity, and 55.4% PPV. CINtec p16INK4a cytology had 85.7% sensitivity, 54.7% specificity, and 49.1% PPV. Cytology of a specimen taken at colposcopy (mild dyskaryosis or worse) had 88.9% sensitivity, 58.1% specificity, and 50.7% PPV. Our study confirms that, in a referral setting, HPV testing by a number of different tests provides high sensitivity for high-grade disease. Further work is needed to confirm these findings in a routine screening setting.

Comparing the performance of six human papillomavirus tests in a screening population

Background:Several new assays have been developed for high-risk HPV testing of cervical samples; we compare six HPV tests in a screening population.Methods:Residual material from liquid-based PreservCyt samples was assayed. Four tests (Hybrid Capture 2, Cobas, Abbott and Becton-Dickinson (BD)) measured HPV DNA while two used RNA (APTIMA and NorChip).Results:Positivity rates ranged from 13.4 to 16.3% for the DNA-based tests with a significantly lower positivity rate for the Abbott assay. The Gen-Probe APTIMA assay was positive in 10.3% of women, which was significantly lower than all the DNA tests; the NorChip PreTect HPV-Proofer test was much lower at 5.2%. 40 CIN2+ cases were identified, of which 19 were CIN3+. All CIN3+ cases were HPV positive by all tests except for one, which was negative by the Abbott assay and five which were negative by the NorChip test.Conclusion:All HPV tests except NorChip showed high sensitivity for high-grade lesions positive by cytology, suggesting co-testing is unnecessary when using HPV tests. Positivity rates in cytology-negative specimens were similar for the DNA-based tests, but lower for the APTIMA test suggesting this maintains the high sensitivity of DNA tests, but with better specificity.

HPV self-sampling as an alternative strategy in non-attenders for cervical screening – a randomised controlled trial

Background:A randomised trial to ascertain whether women who do not attend for cervical screening are more likely to respond to the opportunity to collect a self-sample for human papillomavirus (HPV) testing, or to a further invitation to attend for cervical screening.Methods:The study was carried out in a Primary Care Trust (PCT) in London between June 2009 and December 2009. In total, 3000 women were randomly selected from persistent non-responders (i.e., who had not responded to at least two invitations to attend for screening). The women were randomised on a 1 : 1 basis to either receive an HPV self-sampling kit or a further invitation to attend for cervical cytology. The main outcome measures were (1) percentage of women attending for cervical cytology compared with those returning a self-sample HPV test or attending for cytology subsequent to receiving the kit and (2) percentage of those testing positive for HPV who attended further investigation.Results:The total response in the self-sampling group for screening was 10.2%. Of the 1500 women in the control group sent a further invitation for cervical screening, 4.5% attended for cytology screening. This difference is highly statistically significant (P<0.0001). Of the 8 women who tested positive for HPV, 7 attended for a cervical smear and had a concurrent colposcopy. Three of these (43%) had high-grade disease (defined as CIN 2+), with one found to have an invasive cancer (stage 1b) and one CIN 3.Conclusions:The value of this intervention relies on the detection of high-grade CIN and early stage cancer with a good prognosis. The relatively high yield of abnormalities found is consistent with that expected among a hard to reach and relatively high-risk group of women. Our study suggests that self-sampling could increase participation among non-responders in England, but further work is needed to ascertain whether the low response rate seen here is likely to be representative of the rest of the country. Other studies are needed to investigate the response to self-sampling in different demographic and geographic settings.

Exploring the acceptability of two self-sampling devices for human papillomavirus testing in the cervical screening context: a qualitative study of Muslim women in London

Objectives We explored Muslim womens attitudes to self-sampling for human papillomavirus (HPV) in the context of cervical cancer screening and their responses to two self-sampling devices. Setting A Muslim community centre in north-east London. Methods Following a talk given on the subject of cervical cancer and HPV at the community centre, 28 women were recruited to take part in three focus group discussions. The discussion covered cervical screening, self-sampling and HPV testing. Women were also asked for their responses to a swab self-sampling kit and a cervico-vaginal lavage device. Discussions were recorded and transcribed verbatim and the qualitative data were analysed using Framework Analysis. Results Participants were generally positive about cervical screening but acknowledged that some women in their community were reluctant to attend because of embarrassment, language difficulties, fear or because they were unmarried and did not want to communicate implicit messages about being sexually active. Self-sampling met a mixed response – women were concerned about not doing the test correctly, but thought that it might overcome barriers to screening for some women. HPV testing itself was thought to raise potentially difficult issues relating to trust and fidelity within marriages. Although most women said they would prefer to continue to have screening by a health professional, if they were to perform self-sampling, there was overwhelming preference for the swab over the lavage kit. Conclusions There was limited enthusiasm for self-sampling in this group of Muslim women who had mostly attended for cervical screening, but a clear preference for a swab rather than a cervico-vaginal lavage.

Barriers to cervical screening in women who have experienced sexual abuse: an exploratory study

Objectives To explore self-reported cervical screening history and barriers to attendance among women who have been sexually abused and to identify measures to improve the experience of cervical screening for these women. Methods Women visiting the website of the National Association for People Abused in Childhood (NAPAC), who had been sexually abused, were invited to complete a survey of their views and experiences of cervical screening. This included closed questions on demographic characteristics and cervical screening attendance, open questions on barriers to screening, and the opportunity to submit suggestions to improve this experience for women who have been sexually abused. Content analysis was used to code responses to the open questions. Four women also participated in a discussion group. Results Overall, 135 women completed the closed questions and 124 provided open-ended responses. 77.5% of responding women who were eligible for cervical screening in England had ever attended, 48.5% at least once in the previous 5 years, but 42.1% of women aged 25–49 within 3 years. A total of nine higher order themes were identified related to barriers to screening, one related to intention to attend screening and five related to suggestions to improve screening. Conclusions This study supports the idea that women who have experienced sexual abuse are less likely to attend for regular cervical screening, with under half screened in the last 5 years compared to the National Health Service Cervical Screening Programme figure of 78.6%. Suggestions to improve the experience for abused women focused on communication, safety, trust and sharing control. Further research in this area is warranted to ensure that this at-risk population is appropriately served by cervical screening.

Comparison of human papillomavirus testing strategies for triage of women referred with low-grade cytological abnormalities

AIM To compare triage strategies using different human papillomavirus (HPV) consensus and genotyping tests and a p16(INK4a) test. METHODS 1228 women referred with a borderline or single mildly dyskaryotic smear. Samples were taken at colposcopy using PreservCyt. Tests included Hybrid Capture 2, Abbott RealTime PCR, BD HPV, Cobas 4800, PreTect HPV-Proofer, APTIMA and p16(INK4a). Results were based on the worst histology within 9 months. RESULTS 97/1228 (7.9%) women had CIN3+ (203/1228 (17%) CIN2+). HPV testing alone using Hybrid Capture 2, Abbott RealTime PCR, BD HPV, Cobas 4800 or APTIMA had a sensitivity for CIN3+ ranging from 99.0% to 100.0% and specificity for <CIN2 from 23.3% to 34.7%. p16(INK4a) had a sensitivity of 86.8% and specificity of 50.7%. PreTect HPV-Proofer had a sensitivity of 85.1% and specificity of 73.2%. Testing for HPV type 16 only had sensitivities ranging from 66.0% to 75.5% and specificities from 81.3% to 87.6%. Dual testing with HPV type 16 combined with p16(INK4a) gave a high sensitivity for CIN3+ (78.7% to 98.0%) and specificity for <CIN2 of 58.6% to 81.5%. CONCLUSIONS Triage with sensitive HPV testing assays can substantially reduce the number of unnecessary referrals in women with low grade cytology with virtually no loss of sensitivity. Even greater gains can be made if p16 and type 16 are used, but some cases of CIN2 will be missed. In both cases short term surveillance will be needed.

Individual detection of 14 high risk human papilloma virus genotypes by the PapType test for the prediction of high grade cervical lesions

Background HR HPV genotypes when assayed collectively, achieve high sensitivity but low specificity for the prediction of CIN2+. Knowledge of the specific genotypes in an infection may facilitate the use of HR HPV detection in routine clinical practice. Objectives To compare the rate of HR HPV detection and the accuracy of CIN2+ prediction between PapType test (Genera Biosystems) and other commercially available HR HPV assays, and to examine the value of full HPV genotyping. Study design PreservCyt samples from 1099 women referred for abnormal cervical cytology were used. CIN2+ was chosen as the primary end-point but CIN3+ was also evaluated. A hierarchy of HR HPV genotypes was created using PPV and this was used to create 3 groups of genotypes with potentially different management. Results The PapType assay has a specificity of 22.4% and a sensitivity of 94.6% for CIN2+ prediction. Classification into Groups A (HPV33 and HPV16, very highly predictive), B (HPV31, 18, 52, 35, 58, 51 highly predictive) and C (HPV68, 45, 39, 66, 56, 59, intermediate predictive) could double the specificity (44.5%) but only slightly reduce the sensitivity for CIN2+ (91.5%) and CIN3+ (94.0%). Conclusions The PapType assay is a simple, reproducible and effective test for HR HPV detection and genotyping. HPV 33 was found to have a very high PPV and should therefore be managed as for HPV16.

A randomized controlled trial in non-responders from Newcastle upon Tyne invited to return a self-sample for Human Papillomavirus testing versus repeat invitation for cervical screening.

Background Non-attenders for cervical screening are at increased risk of cervical cancer. Studies offering self-sampling for high-risk Human Papillomavirus (HrHPV) testing have shown greater uptake than sending another invitation for cytology. Objectives To explore whether uptake would increase in a less diverse, more stable population than the previous English study, which demonstrated a lower response rate than other studies. The primary objective was whether non-attenders were more likely to respond to a postal invitation, including kit, to collect a self-sample compared with a further invitation for cytology screening. The secondary objective was whether women with an abnormal result would attend for follow-up. Methods 6000 non-attenders for screening in this pragmatic, randomized (1:1) controlled trial in Newcastle-upon-Tyne were sent an HPV self-sample kit (intervention) or a further invitation for cytology screening (comparator). Results 411(13%) responded to the intervention, returning a self-sample (247(8%)) or attending for cytology (164(5%)), compared with 183(6%) attending for cytology, relative risk 2.25 (95% CI 1.90–2.65) (comparator arm). Of those testing hrHPV positive (32(13%)), 19(59%) subsequently attended cytology screening. Of those in the intervention group who attended for cytology screening without returning an hrHPV self-sample (n = 164), 5% (n = 8) were referred for colposcopy - all attended. In the comparator group eight of the nine referred for colposcopy attended. Conclusion Persistent non-responders to invitations for cervical screening are significantly more likely to respond to a postal invitation to return a self-collected sample for HPV testing than a further invitation for cytology screening. However, just over half followed up on this positive HPV result.

Performance of the Xpert HPV assay in women attending for cervical screening

Objectives This study evaluated the Xpert HPV Assay in women attending screening in general practice by comparing Xpert with two established HPV tests, cytology and histology. Methods A prospective study in women aged 20–60 years attending screening in Bristol, Edinburgh and London using residual Preservcyt cytology samples. Sample order was randomised between Roche cobas4800 and Cepheid Xpert assays with Qiagen hc2 third. Results 3408 cases were included in the primary analysis. Positivity for Xpert was 19.6%, cobas 19.2% and hc2 19.9% with high concordance (kappa=86.8% vs cobas, 81.55 vs hc2). Xpert, cobas and hc2 showed similar sensitivity (98.7%, 97.5%, 98.7%) for CIN2+. All pairwise comparisons had high concordance (Kappa ≥0.78 with any abnormal cytology. Xpert and hc2 were positive for all cases of ≥moderate dyskaryosis (N=63)), cobas was negative in two. Histology was available for 172 participants. 79 reported CIN2+, 47 CIN3+. All CIN3+ was positive on Xpert and hc2 and one case negative for cobas. One case of CIN2 was negative for all assays. Conclusions The performance of Xpert HPV Assay in a general screening population is comparable to established HPV tests. It offers simplicity of testing, flexibility with non-batching of individual samples and rapid turnaround time.

Attitudes towards cytology and human papillomavirus self-sample collection for cervical screening among Hindu women in London, UK: a mixed methods study

Objectives To explore the attitudes, views and understanding of women attending a Hindu temple in London, UK towards cervical screening, human papillomavirus (HPV) testing and two HPV self-sample collection devices: the Dacron swab and Evalyn® brush. Methods A mixed methods design comprising a survey and four focus groups was adopted. Focus group discussions were recorded and transcribed verbatim and explored using thematic framework analysis. Results A total of 185 Hindu women completed surveys and 23 attended focus groups. Of the respondents 75% aged 25–64 years reported having cervical screening within the last 5 years; 85% had attended college or university. Familiar barriers to attendance for screening were identified: fear of pain and the test result, embarrassment, screeners attitude, inconvenient appointment times and difficulty with child care. Additional barriers cited included age and country of birth, with older and Indian-born women thought to be less likely to attend for screening. Self-collected sampling had a mixed reception. Women were not confident that their sample would be as good as a clinician sample and expressed concern about the impact that a positive HPV result might have on their relationships. Conclusions Screening attendance in this highly educated group of Hindu women was slightly lower than in the general population (75% of women aged 25–64 years had been screened in the last 5 years compared with 79% in England as a whole). Familiar barriers to screening were identified. Women felt able to collect their own sample for HPV testing with a Dacron swab but lacked confidence that it would be as good as that obtained by a clinician.