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S Van Keer, M Arbyn, A Vorsters (2021). High-risk HPV testing in first-void urine for cervical cancer screening: a clinical accurate alternative compared to cervical samples. www.HPVWorld.com, 178

During the last decade, more knowledge has been generated related to the use of urine as a sample type for cervical cancer prevention. Urine samples are non-invasive and can be easily collected by the woman herself in the privacy of her own home. Qualitative research furthermore indicates that women prefer urine-based self-sampling to vaginal self-sampling methods. Due to this growing interest, further clarification about why a urine sample is relevant for detection of biomarkers originating from the female genital tract, including HPV DNA, is timely.

The epithelial cell layers of the female genital tract, including cell(s) (debris) from lesions induced by HPV, are continuously exfoliated and subsequently mixed with secretions of the uterus and cervix, which make their way to the vagina and hence can be recognized in vaginal smears¹. These cervicovaginal secretions accumulate around the urethra opening, between the small labia, and are washed away with the initial urine flow. Hence, most of this debris is picked up by the initial flow of urine – first-void urine – without interfering with the natural history of an HPV infection. First-void urine is often mistaken for first urine of the day, which was initially believed to improve urinary HPV DNA detection.

Nonetheless, collecting the first part of the urine stream is certainly important as it contains significantly more HPV DNA compared to random or midstream samples^2,3. Inhibiting DNA degradation by adding a urine conservation medium to the sample immediately upon collection is likewise important to obtain accurate test results³. Higher HPV test agreement between first-void urine and cervical samples and higher clinical sensitivity is obtained in recent clinical trials applying these standardizations^4,5, compared to studies collecting random or midstream urine whether or not immediately preserved.

To date, evidence is mostly available regarding the analytical accuracy of HPV testing in urine compared to cervical samples collected by a clinician². Data about the relative clinical sensitivity and specificity to detect high-grade cervical intraepithelial neoplasia (CIN2+) is well documented for self-collected vaginal versus clinician-collected cervical samples⁶, but still are scarce for first-void urine. The diagnostic test accuracy study VALHUDES was accordingly designed to evaluate the relative clinical performance of validated PCR-based HPV assays in self-collected samples compared to cervical samples collected by a clinician⁷. First results using the Abbott RealTime High Risk HPV assay demonstrate equal clinical sensitivity and specificity of high-risk HPV testing in first-void urine compared to cervical samples (Table 1)⁴. These data are promising as next to self-collected vaginal samples⁶, clinical non-inferiority to detect CIN2+ of high-risk HPV testing in first-void urine compared to cervical samples is confirmed. Strengths of VALHUDES encompass that self-sampling was performed at home, representative of its use in a real-life screening setting. Furthermore, a HPV DNA-based PCR platform already used in routine cancer screening was used to assess clinical accuracy of urinary HPV testing using the identical sample handling procedure and cycle number cut-off on first-void urine as for manufacturer-validated cervical samples. These clinical accuracy outcomes are pivotal to widen sampling strategies and reach un(der)-screened women by offering urine self-collection at home.





The strategy where non-invasive (first-void) urine sampling could receive the highest impact is in a home-based setting, reaching out to un(der)-screened women who are eligible for screening, yet do not participate (Figure 1). A first-void urine self-sampling strategy might be received by women as easier to use. It can furthermore provide an alternative when vaginal self-sampling is not possible due to cultural or religious beliefs, or previous (sexual) trauma. It is important to examine if self-sampling using first-void urine has an added value in reaching screening non-responders, whether or not in combination with a molecular-based reflex test for high-risk HPV-positive women, analysed on the same self-collected sample (Figure 1).

DISCLOSURE Part of this work performed by SVK and AV was supported by the Industrial Research Fund of the University of Antwerp, Belgium (Grant No. PS ID 32387). The employers of MA and AV received funding in the framework of VALHUDES, which is a researcher-induced study (MA is PI of VALHUDES) that evaluates HPV tests on self-samples. SVK, MA and AV did not receive financial or material benefit from this project. Up hereto the following manufacturers participated in VALHUDES: Abbott Laboratories, Roche, BD, Cepheid and Novosanis.University of Antwerp (SVK, AV) is subcontractor in the Eurostars R&D-performing SME Grant CASUS (12396), co-funded by Eureka member countries and the European Union Horizon 2020 framework program (coordinator: Self-screen B.V.; partner: Novosanis).SVK is supported by a junior postdoctoral fellowship of the Research Foundation – Flanders (FWO), Belgium (Grant No. 1240220N).

MA was supported by the Horizon 2020 Framework Programme for Research and Innovation of the European Commission, through the RISCC Network (Grant No. 847845).AV participated in advisory board meetings of Merck. Participation fees are paid directly to an educational fund held by the University of Antwerp. AV works partly for the executive secretariat of the HPV prevention and control board. The secretariat is seated at the Centre for the Evaluation of Vaccination (CEV) of the University of Antwerp, where it has the infrastructure and administrative services of the University at its disposal. The HPV prevention and control board is supported by unrestricted grants from the industry (including: GlaxoSmithKline Biologicals, Sanofi Pasteur MSD, Merck, Abbott and Hologic), several universities in Europe and other institutions. AV is co-founder of Novosanis (Belgium), a spin-off company of the University of Antwerp, and was minority shareholder until January 2019.


References

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2. Pathak, N., Dodds, J., Zamora, J. & Khan, K. Accuracy of urinary human papillomavirus testing for presence of cervical HPV: systematic review and meta-analysis. Bmj 349, g5264 (2014). Available from: https://www.bmj.com/content/349/bmj.g5264

3. Vorsters A, Van den Bergh J, Micalessi I et al. Optimization of HPV DNA detection in urine by improving collection, storage, and extraction. Eur J Clin Microbiol Infect Dis. 33, 2005-2014 (2014). Available from: https://pubmed.ncbi.nlm.nih.gov/24916950/

4.Van Keer S, Peeters E, Vanden Broeck D et al. Clinical and analytical evaluation of the RealTime High Risk HPV assay in Colli-Pee collected first-void urine using the VALHUDES protocol. GGynecol Oncol. 2021 Sep;162(3):575-583. Available from: https://doi.org/10.1016/j.ygyno.2021.06.010

5. Leeman A, Del Pino M, Molijn A et al. HPV testing in first-void urine provides sensitivity for CIN2+ detection comparable with a smear taken by a clinician or a brush-based self-sample: cross-sectional data from a triage population. BJOG 124, 1356-1363 (2017). Available from: https://doi.org/10.1111/1471-0528.14682

6. Arbyn M, Smith SB, Temin S et al. Detecting cervical precancer and reaching underscreened women by using HPV testing on self samples: updated meta-analyses. Bmj 363, k4823 (2018). Available from: https://doi.org/10.1136/bmj.k4823

7. Arbyn M, Peeters E, Benoy I et al. VALHUDES: A protocol for validation of human papillomavirus assays and collection devices for HPV testing on self-samples and urine samples. J Clin Virol 107, 52-56 (2018). Available from: https://doi.org/10.1016/j.jcv.2018.08.006