Detection of high-grade cervical neoplasia using extended genotyping: Performance data from the longitudinal phase of the Onclarity trial

Objectives: The Onclarity cervical cancer screening trial was designed to establish the clinical validity of the Onclarity HPV assay for extended genotyping (xGT) during detection of high-grade cervical neoplasia grades 2 or 3 (≥CIN2 or ≥CIN3). Here, three-year follow up data is presented to evaluate the overall efficacy of these screening strategies, compared to the baseline data.

Methods: At baseline 29,513 women, ≥25 years, had evaluable cytology and valid high-risk HPV results. Women with atypical squamous cells-undetermined significance or worse cytology or a positive HPV test were referred for colposcopy/biopsy. Participants that did not reach the study end point (treatment for ≥CIN2) continued into the longitudinal phase that included the same protocol as baseline.

Results: The three-year cumulative incident risk (CIR) for ≥CIN3 in HPV-negative women was 0.15% [95%CI: 0.06, 0.26] and for HPV- and cytology-negative women was 0.12% [95% CI: 0.03,0.23]. HPV16 carried the highest baseline and three-year ≥CIN3 CIR, followed by HPV31 and HPV18. At least one year of genotype-specific persistence increased ≥CIN3 risk for xGT results compared to genotype non-persistence, HPV clearance, or new infection over the same time period. Risk-based screening with immediate colposcopy for HPV16/18/31 and further xGT triage resulted in better ≥CIN3 sensitivity (79.2% versus 72.3%; relative difference of 6.9 [95%CI: 3.3, 10.4]) and a lower colposcopy/≥CIN3 ratio (9.2 versus 11.2; relative difference of -1.9 [95%CI: -2.6, -1.3]) when compared to primary HPV16/18-based screening.

Conclusions: An HPV-negative result offers the same assurance of no disease over three years of follow up as that offered by a negative co-testing result. xGT facilitates risk-based screening and persistence tracking and can help optimize disease detection during screening without excessive colposcopic procedures.