Enzyme-linked immunosorbent assay for p16INK4a– a new triage test for the detection of cervical intraepithelial neoplasia?
ABSTRACT Objective. To evaluate enzyme-linked immunosorbent assay (ELISA) for cyclin-dependent kinase inhibitor 2A protein (p16INK4a) on self-collected cervicovaginal lavage samples as an additional triage test to identify women with high-grade cervical intraepithelial neoplasia (CIN). Design. Retrospective feasibility, sensitivity and specificity study. Setting. University Medical School, Germany. Sample. One hundred and fifty-two patients from the colposcopy clinic were included. Methods. All women used a cervico-vaginal lavage device (Delphi Screener) for self-sampling and had gynecological examinations with Pap smears, cervical smears in ThinPrep PreservCyt solution and Cervatec medium for human papillomavirus (HPV) testing (Qiagen Hybrid Capture 2) and colposcopic examinations with biopsies if abnormalities were detected (72 women; 51%). All cytological samples were examined by p16INK4a ELISA. Main outcome measures. Sensitivity and specificity of p16INK4a ELISA for high-grade CIN. Results. Complete data were available for 140 women. Among these, 62 women (46%) presented with an atypical Pap smear and 65 (46.4%) were high-risk HPV positive in the reference smear sample. Seventeen women (12%) had CIN 3+. Twenty-seven (19%) physician-collected samples were p16INK4a ELISA positive. In contrast, p16INK4a ELISA turned out to be positive in only one (1%) vaginal lavage sample. Conclusions. Our study shows that self-sampling with cervicovaginal lavage followed by p16INK4a ELISA is not suitable for the detection of high-grade CIN.
SourceAvailable from: Viola Verhoef[Show abstract] [Hide abstract]
ABSTRACT: 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. 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. 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. 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. 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.The Lancet Oncology 01/2014; DOI:10.1016/S1470-2045(13)70570-9 · 24.73 Impact Factor
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ABSTRACT: Cytology is a widely used method of triaging women who test positive for human papillomavirus (HPV). However, self-sampled specimens, which can substantially increase participation in screening programmes, are not suitable for accurate cytological assessment. We investigated whether direct DNA methylation-based molecular triage on self-sampled cervicovaginal specimens was non-inferior to cytology triage on additional physician-collected cervical samples in the detection of cervical intraepithelial neoplasia grade 2 (CIN2) or worse in women who did not attend cervical screening programmes. In this randomised controlled non-inferiority trial, we invited women (aged 33-63 years) registered as non-attendees of cervical screening in the Netherlands in 2007 to submit a self-collected cervicovaginal sample for HPV testing. Using a computer-generated sequence, we randomly allocated women who tested positive for high-risk hrHPV on a self-sample to either triage by cytology on an additional physician-taken smear or direct triage on the self-sample by methylation analysis of MAL and miR-124-2 genes (1:1; stratified by age and region, with block sizes by age group). Triage-positive women in either group were referred for colposcopy. The primary endpoint was detection of CIN2 or worse, analysed by intention to treat. The non-inferiority margin was 0·80. This study is registered in the Primary Trial Register of the Netherlands, number NTR6026. We invited 46 001 women to participate, 12 819 of whom returned self-sampled material; 1038 samples tested positive for high-risk HPV. Between Nov 1, 2010, and Dec 31, 2011, after exclusion of women who were ineligible, we enrolled and randomly allocated 515 women to methylation triage and 509 to cytology triage. The detection of CIN2 or worse with methylation triage was non-inferior to that with cytology triage (90 [17%] of 515 women vs 75 [15%] of 509 women; relative risk 1·19, 95% CI 0·90-1·57). Referral for colposcopy was more common in the molecular group (284 [55%] women) than in the cytology group (149 [29%] women; p<0·0001). Mean time to CIN2 or worse diagnosis was shorter in the molecular triage group (96 days, range 44-101) than in the cytology triage group (158 days, 71-222; p=0·00084). DNA methylation analysis of MAL and miR-124-2 genes on HPV-test-positive self-samples is non-inferior to cytology triage in the detection of CIN2 or worse, opening the way to full molecular screening. Midden-West and Oost Screening Organisations and Stichting Achmea Gezondheidszorg.The Lancet Oncology 02/2014; DOI:10.1016/S1470-2045(14)70019-1 · 24.73 Impact Factor
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ABSTRACT: Methylation markers were studied for their suitability to triage human papillomavirus (HPV)-positive women by testing self-collected cervico-vaginal lavage specimens. For this purpose, we analyzed 355 hrHPV-positive self-collected specimens with three methylation markers, that is, CADM1-m18, MAL-m1 and miR-124-2 by quantitative methylation-specific PCR. The areas under the receiver-operating characteristic (ROC) curve for end-point cervical intraepithelial neoplasia grade 3 or worse (CIN3+) were 0.637 for CADM1-m18, 0.767 for MAL-m1 and 0.762 for miR-124-2. This indicates that CADM1-m18 is not suitable as single marker. By varying the thresholds of both markers in the bi-marker panels CADM1-m18/MAL-m1, CADM1-m18/miR-124-2 and MAL-m1/miR-124-2 upper and lower ROC curves were obtained, depicting the maximum and minimum CIN3+ sensitivity, respectively, at given specificity. For all these bi-marker combinations, the upper curves were similar. However, for the MAL-m1/miR-124-2 panel, the distance between upper and lower ROC curves was closest and this panel displayed the highest assay thresholds, indicating that this combination was most robust. At clinical specificities of 50 and 70%, the MAL-m1/miR-124-2 sensitivity for detection of CIN3+ ranged from 77.0 to 87.8% and from 64.9 to 71.6%, respectively. At 70% specificity thresholds no carcinomas were missed. By comparison, the CIN3+ sensitivity of HPV16/18 genotyping on the self-sampled lavage specimens was 58.1% (95%CI: 46.6-68.8) at a specificity of 87.7% (95%CI: 83.2-91.2). In conclusion, methylation analysis is a promising triage tool that in combination with HPV-DNA testing offers feasible, full molecular screening on self-collected cervico-vaginal lavage specimens.International Journal of Cancer 08/2014; 135(4). DOI:10.1002/ijc.28723 · 5.01 Impact Factor