Clinical Validation of the Vitro HPV Screening Assay for Its Use in Primary Cervical Cancer Screening

Abstract

The advances in cervical cancer screening have mostly focused on high-risk human papillomavirus (HR HPV) detection as the primary screening tool in women over 30 years old. Although many new HPV assays have been commercialized during the last few years, only a few of them are validated according to international guidelines. Recently, new approaches for genotype-based risk-stratification and triage of HPV positive women have been developed. In this study, the Vitro HPV Screening assay targeting 14 oncogenic genotypes (HPV16, HPV18, and another 12 HR HPV genotypes) has demonstrated an appropriate clinical performance to be used as primary screening test. Additionally, the 12 HR HPV genotypes have been individually genotyped with a complementary assay performed by reverse dot blot hybridization of the PCR product from the HPV Screening assay. In conclusion, this n ew assay represents a unique integrated solution for cervical cancer screening with the extended HPV genotyping as a clinical tool for risk determination. Many scientific societies have issued guidelines to introduce population-based cervical cancer screening with HPV testing. The Vitro HPV Screening assay is a fully automatic multiplex real-time PCR test targeting the L1 GP5+/GP6+ region of HPV genome. The assay detects 14 high risk (HR) HPV genotypes, identifying individual HPV16 and HPV18 genotypes, and the HPV-positive samples for the other 12 HR HPV types are subsequently genotyped with the HPV Direct Flow Chip test. Following international guidelines, the aim of this study was to validate the clinical accuracy of the Vitro HPV Screening test on ThinPrep-collected samples for its use as primary cervical cancer screening, using as comparator the validated cobas (R) 4800 HPV test. The non-inferiority analysis showed that the clinical sensitivity and specificity of the Vitro HPV Screening assay for a diagnosis of cervical intraepithelial neoplasia of grade 2 or worse (CIN2+) were not inferior to those of cobas (R) 4800 HPV (p = 0.0049 and p < 0.001 respectively). The assay has demonstrated a high intra- and inter-laboratory reproducibility, also among the individual genotypes. The Vitro HPV Screening assay is valid for cervical cancer screening and it provides genotyping information on HPV-positive samples without further sample processing in a fully automated workflow.