Randomized Comparison of Two Vaginal Self-Sampling Methods for Human Papillomavirus Detection: Dry Swab versus FTA Cartridge

Does self-sampling for human papilloma virus testing have the potential to increase cervical cancer screening? An updated meta-analysis of observational studies and randomized clinical trials

Objectives

A meta-analysis was conducted to examine the effectiveness of HPV self-sampling proposal on cervical cancer screening (CCS) uptake when compared with an invitation to have a clinician to collect the sample. Secondary outcomes were acceptability and preference of self-sampling compared to clinician-collected samples.

Methods

The present systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies examining the CCS uptake comparing self-sampling over invitation to be sampled by an healthcare professional and examining the proportion of women accepting or preferring self-sampling vs. clinician-collected sampling were included. The CCS uptake was also explored according to strategy of self-samplers' distribution, collection device type and screening status. Peters' test and Funnel Plot inspection were used to assess the publication bias. Quality of the studies was assessed through Cochrane Risk of Bias and NIH Quality Assessment tools.

Results

One hundred fifty-four studies were globally identified, and 482,271 women were involved. Self-sampling procedures nearly doubled the probability (RR: 1.8; 95% CI: 1.7-2.0) of CCS uptake when compared with clinician-collected samples. The opt-out (RR: 2.1; 95% CI: 1.9-2.4) and the door-to-door (RR: 1.8; 95% CI: 1.6-2.0) did not statistically significant differ (p = 1.177) in improving the CCS uptake. A higher relative uptake was shown for brushes (RR: 1.6; 95% CI: 1.5-1.7) and swabs (RR: 2.5; 95% CI: 1.9-3.1) over clinician-collected samples. A high between-studies variability in characteristics of sampled women was shown. In all meta-analyses the level of heterogeneity was consistently high (I 2 > 95%). Publication bias was unlikely.

Conclusions

Self-sampling has the potential to increase participation of under-screened women in the CCS, in addition to the standard invitation to have a clinician to collect the sample. For small communities door-to-door distribution could be preferred to distribute the self-sampler while; for large communities opt-out strategies should be preferred over opt-in. Since no significant difference in acceptability and preference of device type was demonstrated among women, and swabs and brushes exhibited a potential stronger effect in improving CCS, these devices could be adopted.

Self-Collection for Cervical Screening Programs: From Research to Reality

In 2018, there were an estimated 570,000 new cases of cervical cancer globally, with most of them occurring in women who either had no access to cervical screening, or had not participated in screening in regions where programs are available. Where programs are in place, a major barrier for women across many cultures has been the requirement to undergo a speculum examination. With the emergence of HPV-based primary screening, the option of self-collection (where the woman takes the sample from the vagina herself) may overcome this barrier, given that such samples when tested using a PCR-based HPV assay have similar sensitivity for the detection of cervical pre-cancers as practitioner-collected cervical specimens. Other advantages of HPV-based screening using self-collection, beyond the increase in acceptability to women, include scalability, efficiency, and high negative predictive value, allowing for long intervals between negative tests. Self-collection will be a key strategy for the successful scale up of cervical screening programs globally in response to the WHO call for all countries to work towards the elimination of cervical cancer as a public health problem. This review will examine self-collection for HPV-based cervical screening including the collection devices, assays and possible routine laboratory processes considering how they can be utilized in cervical screening programs.

Is self-sampling to test for high-risk papillomavirus an acceptable option among women who have been treated for high-grade cervical intraepithelial neoplasia?

Objective

Self-sampling to test for high risk human papilloma virus (HPV) is becoming an increasingly important component of cervical cancer screening. The aim of this observational study is to examine how women treated for high-grade cervical intraepithelial neoplasia (CIN) view HPV self-sampling.

Methods

Invited to participate in the present study were patients who had undergone treatment of high-grade CIN (grade 2 or higher) and were followed-up at 6-months at the Karolinska University Hospital, Stockholm. The participants were instructed as to how to perform HPV self-sampling. Thereafter, the participants completed a questionnaire about HPV self-sampling and other cervical cancer screening methods, as well as about self-perceived risk of cervical cancer without regular gynecologic follow-up and about specific knowledge regarding HPV, CIN and cervical cancer.

Results

Altogether 479 women enrolled in this study. The participation rate was 96.6%. Nearly 75% of the participants stated they would consider performing the HPV self-sampling prior to their next gynecologic follow-up. Confidence in HPV self-sampling was a significant independent predictor of willingness to perform HPV self-sampling. However, confidence in HPV self-sampling was significantly lower than confidence in Papanicolaou smears and in HPV testing with samples collected by health professionals. Higher specific knowledge about HPV, CIN and cervical cancer was also a significant independent predictor of willingness to perform HPV self-sampling, as was having travelled longer distance to attend gynecologic follow-up. Participants with lower income and without completed university education expressed significantly higher confidence in HPV self-sampling and lower confidence in Papanicolaou smears than the other women.

Conclusions

To the best of our knowledge, this is the first study to examine the views of women treated for high-grade CIN vis-à-vis HPV self-sampling. The latter is an acceptable option for the vast majority of this cohort of women.

Time and temperature dependent analytical stability of dry-collected Evalyn HPV self-sampling brush for cervical cancer screening

As a new initiative, HPV self-sampling to non-attenders using the dry Evalyn self-sampling brush is offered in the Capital Region of Denmark. The use of a dry brush is largely uncharted territory in terms of analytical stability. In this study we aim to provide evidence on the analytical quality of dry HPV self-sampling brushes as a function of time and temperature.

We assessed the analytical stability of dry stored Evalyn brushes at three different temperatures, (4 °C, room temperature, 30 °C) and five different storage time points; T = 0 (baseline), 2, 4, 8, 16, and 32 weeks prior to HPV analysis using the BD Onclarity HPV assay.

Mean Ct value of the Onclarity internal control was used as comparator of cellularity across time and temperatures, with no or only borderline statistical differences observed. HPV detection was stable throughout the five time points. In addition, analytically amplifiable DNA copy numbers and DNA fragmentation was assessed using the Agena iPLEX Exome QC assay, with no or only borderline statistical differences observed.

In conclusion, the Evalyn brush is analytically stable with respect to human genomic material and HPV detection for up to 32 weeks at temperatures ranging from 4 °C to 30 °C.

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The Capital Region of Denmark is implementing HPV self-sampling using a dry brush.

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But how analytically stable is a dry collected self-sampling device?

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Stability was established for both human DNA (all, N = 637) and HPV (positives, N = 41).

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We found the Evalyn Self-sampling brush stable up to 6 month.

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Neither 4 °C nor 30 °C changed the analytical stability of the dry brush.

Test performance and acceptability of self- versus provider-collected swabs for high-risk HPV DNA testing in female-to-male trans masculine patients

Background

High-risk human papillomavirus (hrHPV) causes virtually all cervical cancers. Trans masculine (TM) people (those assigned female at birth who identify with a gender other than female) have low uptake of conventional cervical cancer screening. Self-collected hrHPV DNA testing has high levels of acceptability among cisgender (non-transgender) females and may support increased cervical cancer screening uptake in TM individuals.

Objective

To assess the test performance and acceptability of self-collected vaginal specimens in comparison to provider-collected cervical swabs for hrHPV DNA detection in TM individuals ages 21–64 years.

Methods

Between March 2015-September 2016, 150 TM participants with a cervix (mean age = 27.5 years; SD = 5.7) completed a one-time study visit comprised of a self-report survey, self-collected vaginal HPV DNA swab, clinician-administered cervical HPV swab, and brief interview on acceptability of clinical procedures. Participants were randomized to complete either self- or provider-collection first to minimize ordering effects. Self- and provider-collected samples were tested for 13 hrHPV DNA types using a DNA Hybridization Assay. The primary outcome variable was the concordance (kappa statistic) and performance (sensitivity, specificity) of self-collected vaginal HPV DNA specimens versus provider-collected cervical HPV swabs as the gold standard.

Results

Of the 131 participants completing both the self- and provider-collected HPV tests, 21 cases of hrHPV were detected by the provider cervical swab (gold standard; 16.0% hrHPV prevalence); 15 of these cases were accurately detected by the self-collected vaginal swab (71.4% concordance) (Kappa = 0.75, 95% Confidence Interval [CI]: 0.59, 0.92; p<0.001). Compared to the provider-collected cervical hrHPV DNA sample (gold standard), the self-collected vaginal hrHPV DNA test demonstrated a sensitivity of 71.4% (95% CI: 0.52, 0.91; p = 0.0495) and specificity of 98.2% (95% CI: 0.96, 1.00; p<0.0001). Over 90% of participants endorsed a preference for the self-collected vaginal swab over provider-collected cervical swab.

Conclusion

Self-collected vaginal swabs are highly acceptable to TM as a means to test for hrHPV DNA. Test performance of this self-collection method for hrHPV detection in TM is consistent with previous studies in cisgender females. Self-collected vaginal swab testing for hrHPV DNA represents a reasonable and patient-centered strategy for primary cervical cancer screening in TM patients unwilling to undergo provider collection of specimens via speculum exam.

Safety and acceptability of human papillomavirus testing of self-collected specimens: A methodologic study of the impact of collection devices and HPV assays on sensitivity for cervical cancer and high-grade lesions

BACKGROUND

Comparative data on different self-collection methods is limited.

OBJECTIVES

To assess the impact of hrHPV testing of two self-collection devices for detection of cervical carcinoma and high-grade lesions.

STUDY DESIGN

Three hundred ten patients collected two cervicovaginal specimens using a brush (Evalyn^®Brush) and a swab (FLOQSwabs™), and filled a questionnaire at home. Then, a physician at the clinic took a cervical specimen into PreservCyt^® buffer for hrHPV testing and cytology. All specimens were tested using Anyplex™ II HPV28, Cobas^® 4800 HPV Test and Xpert^®HPV.

RESULTS

Performance comparison included 45 cervical carcinomas and 187 patients with premalignant lesions. Compared to the physician-specimen, hrHPV testing of Evalyn^®Brush showed non-inferior sensitivity for CIN3+ (relative sensitivity of Anyplex™ 0.99; Cobas^® 0.96; Xpert^®HPV 0.97) while hrHPV testing of FLOQSwabs™ showed inferior sensitivity (relative sensitivity of Anyplex™ 0.91; Cobas^® 0.92; Xpert^®HPV 0.93). Similar results were observed for invasive carcinomas albeit that FLOQSwabs™ was statistically non-inferior to the physician-specimen. Self-collection by either Evalyn^®Brush or FLOQSwabs™ was more sensitive for CIN3+ than LSIL or worse cytology. Significant decrease in sensitivity for CIN3+ were observed for FLOQSwabs™ when specimens were preprocessed for hrHPV testing after 28 days. Both devices were well accepted, but patients considered Evalyn^®Brush easier and more comfortable than FLOQSwabs™.

CONCLUSIONS

Self-collection is comparable to current screening practice for detecting cervical carcinoma and CIN3+ but device and specimen processing effects exist. Only validated procedure including collection device, hrHPV assay and specimen preparation should be used.

Accuracy of self-collected vaginal dry swabs using the Xpert human papillomavirus assay

BACKGROUND

Polymerase chain reaction-based Xpert human papillomavirus (HPV) assay is a rapid test that detects high-risk HPV (hrHPV) infection. This point-of-care test is usually performed by collecting a cervical specimen in a vial of PreservCyt® transport medium. We compared HPV test positivity and accuracy between self-collected sample with a dry swab (s-DRY) versus physician-collected cervical sampling using a broom like brush and immediate immersion in PreservCyt (dr-WET).

METHODS

In this cross-sectional study, we recruited 150 women ≥ 18 years old attending the colposcopy clinic in the University Hospital of Geneva. Each participant first self-collected a vaginal sample using a dry swab and then the physician collected a cervical specimen in PreservCyt. HPV analysis was performed with Xpert. Part of the PreservCyt-collected sample was used for hrHPV detection with the cobas® HPV test. HPV test positivity and performance of the two collection methods was compared.

RESULTS

HPV positivity was 49.1% for s-DRY, 41.8% for dr-WET and 46.2% for cobas. Good agreement was found between s-DRY and dr-WET samples (kappa±Standard error (SE) = 0.64±0.09,), particularly for low-grade squamous intraepithelial lesions (LSIL+) (kappa±SE = 0.80±0.17). Excellent agreement was found between the two samples for HPV16 detection in general (kappa±SE = 0.91±0.09) and among LSIL+ lesions (kappa±SE = 1.00±0.17). Sensitivities and specificities were, respectively, 84.2% and 47.1%(s-DRY), 73.1% and 58.7%. (dr-WET) and 77.8% and 45.7% (cobas) for CIN2+ detection. The median delay between sampling and HPV analysis was 7 days for the Xpert HPV assay and 19 days for cobas. There were 36 (24.0%) invalid results among s-DRY samples and 4 (2.7%) among dr-WET (p = 0.001). Invalid results happened due to the long interval between collection and analysis.

CONCLUSION

Self-collected vaginal dry swabs are a valid alternative to collecting cervical samples in PreservCyt solution for HPV testing with the Xpert HPV assay.

IMPACT

HPV self-collection with dry cotton swabs might assist in the implementation of an effective screening strategy in developing countries.

TRIAL REGISTRATION

International Standard Randomized Controlled Trial Number Registry ISRCTN83050913.

Protein Detection Using the Multiplexed Proximity Extension Assay (PEA) from Plasma and Vaginal Fluid Applied to the Indicating FTA Elute Micro Card™

The indicating FTA elute micro card™ has been developed to collect and stabilize the nucleic acid in biological samples and is widely used in human and veterinary medicine and other disciplines. This card is not recommended for protein analyses, since surface treatment may denature proteins. We studied the ability to analyse proteins in human plasma and vaginal fluid as applied to the indicating FTA elute micro card™ using the sensitive proximity extension assay (PEA). Among 92 proteins in the Proseek Multiplex Oncology Iv2 panel, 87 were above the limit of detection (LOD) in liquid plasma and 56 among 92 above LOD in plasma applied to FTA cards. Washing and protein elution protocols were compared to identify an optimal method. Liquid-based cytology samples showed a lower number of proteins above LOD than FTA cards with vaginal fluid samples applied. Our results demonstrate that samples applied to the indicating FTA elute micro card™ are amendable to protein analyses, given that a sensitive protein detection assay is used. The results imply that biological samples applied to FTA cards can be used for DNA, RNA and protein detection.