Clinical and analytical performance of the CLART HPV 4S assay with SurePath screening samples from the Danish cervical cancer screening program using the VALGENT framework

Does full HPV genotyping perform similarly well in clinician-collected cervical samples and self-collected vaginal samples when using the CLART HPV4S assay?

BACKGROUND

Studies comparing self-collected vaginal samples with clinician-collected cervical samples with respect to high-risk human papillomavirus (HPV) detection and genotype agreement based on clinically validated full HPV genotype assays (e.g. the CLART HPV4S) are limited. This study compared the two types of samples using the CLART assay with respect to HPV detection and genotype agreement in a referral population.

METHODS

A total of 212 women aged 30-59 years and diagnosed with atypical squamous cells of undetermined significance (ASC-US) within the Danish cervical cancer screening programme had a cervical sample taken at their general practitioner. Afterwards, the women took a vaginal sample with the Evalyn Brush device at home. The paired samples were HPV-tested with the full genotyping CLART HPV4S assay. Histological results, i.e. cervical intraepithelial neoplasia of grade 2 or worse (CIN2+) were available for 14 women with HPV-positive clinician-collected samples.

RESULTS

The study found the same HPV prevalence in self-collected vaginal samples compared to clinician-collected cervical samples (19.3%, 95% CI 14.3-25.3% vs 18.4%, 95% CI 13.4-24.3%). The CLART HPV4S assay detected approximately the same number of CIN2+ cases in the self-collected vaginal samples compared to the clinician-collected cervical samples (13 vs 11 cases). Exactly the same genotypes were detected in 75% (21/28) of the HPV-positive paired samples, while at least one identical genotype was found in the remaining 25% (7/28) of the paired samples.

CONCLUSIONS

The CLART HPV4S assay performed similarly well in self-collected vaginal samples as in clinician-collected cervical samples with respect to both HPV detection and genotype agreement when using the Evalyn Brush and the CLART HPV4S assay in a referral population. Although further evaluation is needed, the findings suggest that full HPV genotyping based on the CLART assay can be useful when establishing HPV genotype-specific referral strategies for women tested HPV-positive by self-sampling.

Clinical Performance of the Full Genotyping Agena MassARRAY HPV Assay Using SurePath Screening Samples within the VALGENT4 Framework

The clinical performance evaluation of the novel MassARRAY human papillomavirus (MA-HPV) assay was performed using Danish SurePath cervical cancer screening samples under the fourth Validation of HPV Genotyping Tests (VALGENT) framework. The MA-HPV assay is a mass array-based assay that individually detects 14 oncogenic HPV genotypes and five nononcogenic types. The MA-HPV assay was validated using the VALGENT4 panel, which constitutes 997 consecutive samples from a screening population in addition to 297 disease-enriched samples with abnormal cytology findings. The clinical accuracy of the MA-HPV assay for sensitivity and specificity was assessed relative to that of the general primer 5+/6+ PCR enzyme immunoassay (GP-EIA), by a noninferiority test. The type-specific concordance of the MA-HPV assay was assessed as well. The relative sensitivity of the MA-HPV assay for cervical intraepithelial neoplasia ≥2 or ≥3 was 1.02 (95% CI, 0.98-1.05) and 1.01 (95% CI, 0.99-1.04), respectively. The sensitivity of the MA-HPV was noninferior to that of the GP-EIA (P = 0.0001), whereas the specificity of the MA-HPV was inferior (0.89; 95% CI, 0.85-0.91; P > 0.99). The MA-HPV assay is a clinical sensitive assay with a lower clinical specificity compared with the GP-EIA. The assay in its current form seems more suited to play a role where specificity is of lesser importance but where high sensitivity is paramount.