Evaluation of self-sampling-based cervical cancer screening strategy using HPV Selfy CE-IVD test coupled with home-collection kit: a clinical study in Italy

BACKGROUND

Primary human papillomaviruses (HPV) cervical cancer screening can be strengthened by offering home-collection of biological specimen as a valuable option to increase screening coverage. As recommended by World Health Organization (WHO), screening programs should consider whether the inclusion of HPV self-sampling as a complementary option within their existing screening algorithms could address the gaps in current coverage. However, few HPV screening tests are validated for self-sampling according to international guidelines. This study aimed to test a self-sampling-based screening strategy, complementary to the main screening program based on clinician-collected cervical samples. The study took place in Trieste, Italy, and it aimed to evaluate the feasibility of self-testing at home under an opt-in system during COVID-19 pandemic in order to exploit self-sampling to reduce the screening delay generated by the lockdown.

METHODS

500 women, who should have received the screening call in 2020, were asked, via phone call, to participate in the study. To whom agreed, a home-collection kit, including a vaginal dry swab for specimen collection, was sent. The recipients performed the sample self-collection and sent back the swab through traditional mail using a prepaid envelope. Once received by the hospital, the samples were analyzed with HPV Selfy (Ulisse BioMed, Italy), a CE-IVD HPV screening test specifically validated for self-collection. Results were further compared using cobas® 4800 HPV (Roche, Switzerland).

RESULTS

80% women sent back their swab, showing one of the highest return rate obtained in comparable studies. 34 HPV-positive women were followed up and underwent the Pap test, that revealed 8 low squamous intraepithelial lesions (LSIL) cases, later triaged to colposcopy. HPV Selfy was confirmed to be an adequate test for self-sampling-based screening.

CONCLUSIONS

This study further confirmed the feasibility of self-test at home screening strategy based on self-sampling with an opt-in system as a support method to enhance cervical cancer screening coverage in Italy. Enrolled women showed a high appreciation for this approach. HPV Selfy test demonstrated to be a valuable assay for cervical cancer screening based on home self-collection.

TRIAL REGISTRATION

ASUGI Trieste n. 16008/2018 and amendment 02-11/09/2020.

Clinical Performance of the RealTime High Risk HPV Assay on Self-Collected Vaginal Samples within the VALHUDES Framework

The VALHUDES framework (NCT03064087) was established to evaluate the clinical accuracy of HPV testing on self-samples compared with HPV testing on matched clinician-taken cervical samples. Women referred to colposcopy due to previous cervical abnormalities were recruited at five Belgian colposcopy centers. A total of 486 pairs of matched cervical samples and vaginal self-samples were included in the analysis (228 collected with Evalyn Brush and 258 with Qvintip). The dry vaginal brushes were transferred into 20 mL ThinPrep PreservCyt solution. All specimens were tested with the Abbott RealTime High Risk HPV assay (Abbott RT). Testing on vaginal and cervical specimens was considered the index and comparator tests, respectively, and colposcopy and histology as the reference standard. The clinical sensitivity for CIN2+ of Abbott RT (cutoff ≤32 cycle number [CN]) on vaginal self-samples (Evalyn Brush and Qvintip combined) was 8% lower than on the cervical clinician-collected samples (ratio = 0.92 [95% CI, 0.87 to 0.98]), while the specificity was similar (ratio = 1.04 [95% CI, 0.97 to 1.12]). Sensitivity (ratio = 0.95 [95% CI, 0.89 to 1.02]) and specificity (ratio = 1.11 [95% CI, 0.995 to 1.23]) on Evalyn Brush samples was similar to cervical, while on Qvintip samples, the sensitivity was 12% lower than cervical samples (ratio = 0.88 [95% CI, 0.78 to 0.998]) with similar specificity (0.99 [95% CI, 0.90 to 1.10]). Exploratory cutoff optimization (cutoff ≤35 CN) resulted in an improvement of the relative sensitivity (self-sampling versus clinician sampling: ratio = 0.96 [95% CI, 0.91 to 1.02]) but yielded a loss in relative specificity (ratio = 0.92 [0.85 to 1.00]). The clinical accuracy of Abbott RT differed from the self-sampling device. However, after cutoff optimization, the sensitivity on self-samples taken with either of two vaginal brushes became similar to clinician-collected samples. IMPORTANCE Self-samples are becoming a crucial part of HPV-based cervical cancer screening programs to reach nonattendee women and increase screening coverage. Therefore, the VALHUDES framework was established to validate and evaluate HPV tests and devices on self-samples. Here, in the present manuscript, we evaluated the accuracy of the RealTime High Risk HPV assay (Abbott RT) on two different vaginal devices to detect cervical intraepithelial neoplasia grade two or higher (CIN2+). The study results demonstrated that the Abbott RT assay is similarly accurate on vaginal self-samples as on matched clinician-taken cervical samples after adjusting cutoff values. Moreover, we observed that some vaginal devices perform better than others in CIN2+ detection. We also underline the necessity of standardization and validation of general workflow and sample handling procedures for vaginal self-samples.

Clinical validation of full HR-HPV genotyping HPV Selfy assay according to the international guidelines for HPV test requirements for cervical cancer screening on clinician-collected and self-collected samples

BACKGROUND

According to international guidelines, Human Papillomavirus (HPV) DNA tests represent a valid alternative to Pap Test for primary cervical cancer screening, provided that they guarantee balanced clinical sensitivity and specificity for cervical intraepithelial neoplasia grade 2 or more (CIN2+) lesions. The study aimed to assess whether HPV Selfy (Ulisse BioMed - Trieste, Italy), a full-genotyping HPV DNA test that detects and differentiates 14 high-risk HPV (HR-HPV) types, meets the criteria for primary cervical cancer screening described in the international guidelines, on clinician-collected as well as on self-collected samples.

METHODS

For each participant woman, consecutively referring to Azienda Sanitaria Universitaria Giuliano Isontina (Trieste, Italy) and CRO-National Cancer Institute (Aviano, Italy) for the cervical cancer screening program, the following samples were tested: (a) a clinician-collected cervical specimen, analyzed with the reference test (Hybrid Capture®2 test, HC2) and HPV Selfy; and (b) a self-collected vaginal sample, analyzed with HPV Selfy. Enrolled women were also asked to fulfill a questionnaire about self-sampling acceptability. As required by guidelines, a non-inferiority test was conducted to compare the clinical performance of the test under evaluation with its reference test.

RESULTS

HPV Selfy clinical sensitivity and specificity resulted non-inferior to those of HC2. By analysis of a total of 889 cervical liquid-based cytology samples from a screening population, of which 98 were from women with CIN2+, HPV Selfy showed relative sensitivity and specificity for CIN2+ of 0.98 and 1.00 respectively (non-inferiority score test: P = 0.01747 and P = 0.00414, respectively); the test reached adequate intra- and inter-laboratory reproducibility. Moreover, we demonstrated that the performance of HPV Selfy on self-collected vaginal samples was non-inferior to the performance obtained on clinician-collected cervical specimen (0.92 relative sensitivity and 0.97 relative specificity). Finally, through HPV Selfy genotyping, we were able to describe HPV types prevalence in the study population.

CONCLUSIONS

HPV Selfy fulfills all the requirements of the international Meijer's guidelines and has been clinically validated for primary cervical cancer screening purposes. Moreover, HPV Selfy has also been validated for self-sampling according to VALHUDES guidelines. Therefore, at date, HPV Selfy is the only full-genotyping test validated both for screening purposes and for self-sampling. Trial registration ASUGI Trieste n. 16008/2018; CRO Aviano n.17149/2018.

Cervical cancer screening using HPV tests on self-samples: attitudes and preferences of women participating in the VALHUDES study

Background

Interventions to reach women who do not participate regularly in screening may reduce the risk of cervical cancer. Self-collection of a vaginal specimen has been shown to increase participation. The relative clinical accuracy of human papillomavirus (HPV) testing on first-void urine (with Colli-Pee) and on vaginal self-samples versus on cervical clinician-collected samples is being investigated in the VALHUDES trial. The current study assesses attitudes and experiences regarding self-sampling among women enrolled in VALHUDES.

Methods

Questionnaires from 515 women (age 25–64 years [N = 498]; < 25 [N = 10], age ≥ 65 [N = 3], enrolled between December 2017 - January 2020) referred to colposcopy because of previous cervical abnormalities and enrolled in VALHUDES (NCT03064087) were analysed.

Results

Of the 515 participants, nearly all women confirmed that self-sampling may help in reaching under-screened women (93%). Nevertheless, 44% of the participants stated before starting collection that a clinician-collected sample is more effective than a self-collected sample. After self-sampling, the large majority of women (> 95%) declared that instructions for self-collection were clear, that collection was easy, and that they were confident about having performed the procedure correctly, for both urine and vaginal collection. However, a proportion of women found self-sampling unpleasant (9.5% [49/515] for urine collection; 18.6% [96/515] and 15.5% [80/515] for vaginal sampling with cotton swabs or plastic brushes, respectively). For their next screening round, 57% would prefer self-sampling whereas 41% opted for collection by a clinician. Among women preferring self-sampling, 53% would choose for urine collection, 38% for vaginal self-collection and 9% had no preference. Age did not modify preferences.

Conclusion

We conclude that both urine and vaginal self-sampling are well accepted by women, with a preference for urine sampling. Although the large majority of women are confident in their ability to perform self-sampling, four to five over ten women preferred specimen collection by a clinician.

Trial registration

The study VALHUDES was registered in ClinicalTrials.gov (identifier: NCT03064087).

Supplementary Information

The online version contains supplementary material available at 10.1186/s13690-021-00667-4.

Clinical and analytical evaluation of the RealTime High Risk HPV assay in Colli-Pee collected first-void urine using the VALHUDES protocol

OBJECTIVE

Urine self-sampling has gained increasing interest for cervical cancer screening. In contrast to analytical performance, little information is available regarding the clinical accuracy for high-risk Human Papillomavirus (hrHPV) testing on urine.

METHODS

VALHUDES is a diagnostic test accuracy study comparing clinical accuracy to detect high-grade cervical precancer (CIN2+) of HPV testing on self-collected compared to clinician-collected samples (NCT03064087). Disease outcome was assessed by colposcopy and histology. The Abbott RealTime High Risk HPV assay performance was evaluated on Colli-Pee collected first-void urine with cervical outcomes as comparator.

RESULTS

As no assay cut-off for urine has been clinically validated, we used the predefined cut-off for cervical samples (CN ≤ 32). Using this cut-off, hrHPV testing was similarly sensitive (relative sensitivity 0.95; 95% CI: 0.88-1.01) and specific (relative specificity 1.03; 95% CI: 0.95-1.13) for detection of CIN2+ compared to testing cervical samples. In the subgroup of women of 30 years and older, similar relative sensitivity (0.97; 95% CI: 0.89-1.05) and specificity (1.02; 95% CI: 0.93-1.12) was found. Additionally, an exploratory cut-off (CN ≤ 33.86) was defined which further improved sensitivity and analytical test performance.

CONCLUSION

HrHPV-DNA based PCR testing on home-collected first-void urine has similar accuracy for detecting CIN2+ compared to cervical samples taken by a clinician.

VALHUDES: A protocol for validation of human papillomavirus assays and collection devices for HPV testing on self-samples and urine samples

BACK GROUND

Systematic reviews have concluded that hrHPV DNA testing using target-amplification tests is as accurate on vaginal self-samples as on clinician-taken specimens for the detection of cervical precancer. However, insufficient evidence is available for specific HPV assay/self-sample device combinations.

OBJECTIVES

The VALHUDES protocol is designed as a diagnostic test accuracy study that aims to compare the clinical sensitivity and specificity of particular hrHPV assay(s) on vaginal self-samples and first-void-urine, collected in agreement with standardized protocols, with hrHPV testing on matched clinician-taken samples.

STUDY DESIGN

Five hundred enrolled women referred to a colposcopy clinic are invited to collect a first-void urine sample and one or more vaginal self-samples with particular devices before collection of a cervical sample by a clinician. Sample sets are subsequently analysed in a laboratory accredited for HPV testing. Disease verification for all enrolled patients is provided by colposcopy combined with histological assessment of biopsies.

RESULTS

A first VALHUDES study has started in Belgium in December 2017 with enrolment from four colposcopy centres. The following assays are foreseen to be evaluated: RealTime High Risk HPV assay (Abbott), cobas-4800 and -6800 (Roche), Onclarity (BD), Xpert HPV (Cepheid) and Anyplex II HPV HR (Seegene).

CONCLUSION

Given empirical evidence that the relative accuracy of HPV-testing on self- vs clinician-samples is robust across clinical settings, the VALHUDES protocol offers a framework for validation of HPV assay/self-sample device combinations that can be translated to a primary screening setting.