Need for expanded HPV genotyping for cervical screening

Clinical and Analytical Evaluation of the Anyplex II HPV HR Detection Assay within the VALGENT-3 Framework

In 2012, VALidation of human papillomavirus (HPV) GENotyping Tests (VALGENT) was initiated to provide a formalized and uniform study framework for comparison and validation of HPV assays with genotyping capability. In VALGENT-3, the clinical and analytical performance of Anyplex II HPV HR detection (Anyplex) was compared to that of the Hybrid Capture 2 HPV DNA test (hc2) and the cobas 4800 HPV test (cobas). The panel comprises 1,300 stored samples that were obtained from women 25 to 64 years old who participated in the Slovenian cancer screening program, enriched with 300 samples from women with abnormal cervical cytology. The sensitivity and specificity of Anyplex were noninferior to those of hc2, with a relative sensitivity of 1.01 (95% confidence interval [CI], 0.97 to 1.04) for cervical intraepithelial neoplasia grade 2 or worse (CIN2+) and 1.01 (95% CI, 0.97 to 1.06) for CIN3+ and relative specificity of 1.02 (95% CI, 1.00 to 1.03) for a CIN grade of ≤1. The clinical sensitivity of Anyplex for CIN2+ and CIN3+ was comparable to that of hc2 (P values for McNemar test [p _McN] of 0.655 and 0.564, respectively), but its specificity was significantly higher (p _McN = 0.008). The sensitivity and specificity of Anyplex were also noninferior to those of cobas, with relative sensitivity of 1.01 (95% CI, 0.98 to 1.04) for CIN2+ and 1.01 (95% CI, 0.99 to 1.04) for CIN3+ and relative specificity of 1.00 (95% CI, 0.99 to 1.01) (p _McN value of >0.05 in all cases). Regardless of the clinical outcome (CIN2+ or CIN3+), age restriction (women ≥30 years old), or comparator test used, Anyplex consistently showed excellent clinical performance and can be considered validated for primary cervical cancer screening.

Clinical Evaluation of INNO-LiPA HPV Genotyping EXTRA II Assay Using the VALGENT Framework

In this diagnostic test validation study, we assessed the clinical accuracy and HPV genotyping performance of the INNO-LiPA HPV Genotyping Extra II (INNO-LiPA) within the VALGENT-3 framework. VALGENT is designed to assess the analytical and clinical performance of HPV tests with genotyping capacity. The VALGENT-3 panel comprised 1300 consecutive cervical cell specimens enriched with 300 samples with abnormal cytology obtained from women attending the Slovenian cervical cancer screening programme. The INNO-LiPA allows type-specific detection of 32 HPV types; however, for the clinical accuracy assessment, we considered it as high-risk (hr)HPV positive when at least one of the following HPV types was present: HPV16, HPV18, HPV31, HPV33, HPV35, HPV39, HPV45, HPV51, HPV52, HPV56, HPV58, HPV59, and HPV68. Clinical accuracy for detection of cervical intraepithelial neoplasia grade 2 or worse (CIN2+) was compared between INNO-LiPA and Hybrid Capture 2 (HC2), which is a standard comparator test for HPV tests used in cervical cancer screening. In addition, hrHPV and type-specific detection HPV types were compared between INNO-LiPA and Linear Array HPV Genotyping Test (Linear Array). The prevalence of hrHPV determined by INNO-LiPA was 17.1% (95% CI, 15.0⁻19.2%) in the screening population. HrHPV testing with INNO-LiPA had a sensitivity for CIN2+ of 96.9% (95% CI, 92.1⁻99.1%) which was non-inferior to HC2 (relative sensitivity of 1.01; 95% CI, 0.97⁻1.04; p_n.inf = 0.0002) and a specificity for ≤CIN1 of 85.3% (95% CI, 83.2⁻87.3%) which was inferior to HC2 (relative specificity of 0.95; 95% CI, 0.93⁻0.97; p_n.inf = 0.9998). Genotyping agreement between INNO-LiPA and Linear Array was excellent for hrHPV, HPV16, HPV18, HPV35, HPV45, HPV58 and HPV59, but good or fair for other HPV types. To conclude, INNO-LiPA demonstrated non-inferior clinical sensitivity but lower specificity compared to HC2 in addition to excellent concordance compared to Linear Array for hrHPV and some genotypes.

Optimal Management Strategies for Primary HPV Testing for Cervical Screening: Cost-Effectiveness Evaluation for the National Cervical Screening Program in Australia

BACKGROUND

Several countries are implementing a transition to HPV testing for cervical screening in response to the introduction of HPV vaccination and evidence indicating that HPV screening is more effective than cytology. In Australia, a 2017 transition from 2-yearly conventional cytology in 18-20 to 69 years to 5-yearly primary HPV screening in 25 to 74 years will involve partial genotyping for HPV 16/18 with direct referral to colposcopy for this higher risk group. The objective of this study was to determine the optimal management of women positive for other high-risk HPV types (not 16/18) ('OHR HPV').

METHODS

We used a dynamic model of HPV transmission, vaccination, natural history and cervical screening to determine the optimal management of women positive for OHR HPV. We assumed cytology triage testing was used to inform management in this group and that those with high-grade cytology would be referred to colposcopy and those with negative cytology would receive 12-month surveillance. For those with OHR HPV and low-grade cytology (considered to be a single low-grade category in Australia incorporating ASC-US and LSIL), we evaluated (1) the 20-year risk of invasive cervical cancer assuming this group are referred for 12-month follow-up vs. colposcopy, and compared this to the risk in women with low-grade cytology under the current program (i.e. an accepted benchmark risk for 12-month follow-up in Australia); (2) the population-level impact of the whole program, assuming this group are referred to 12-month surveillance vs. colposcopy; and (3) the cost-effectiveness of immediate colposcopy compared to 12-month follow-up. Evaluation was performed both for HPV-unvaccinated cohorts and cohorts offered vaccination (coverage ~72%).

FINDINGS

The estimated 20-year risk of cervical cancer is ≤1.0% at all ages if this group are referred to colposcopy vs. ≤1.2% if followed-up in 12 months, both of which are lower than the ≤2.6% benchmark risk in women with low-grade cytology in the current program (who are returned for 12-month follow-up). At the population level, immediate colposcopy referral provides an incremental 1-3% reduction in cervical cancer incidence and mortality compared with 12-month follow-up, but this is in the context of a predicted 24-36% reduction associated with the new HPV screening program compared to the current cytology-based program. Furthermore, immediate colposcopy substantially increases the predicted number of colposcopies, with >650 additional colposcopies required to avert each additional case of cervical cancer compared to 12-month follow-up. Compared to 12-month follow-up, immediate colposcopy has an incremental cost-effectiveness ratio (ICER) of A$104,600/LYS (95%CrI:A$100,100-109,100) in unvaccinated women and A$117,100/LYS (95%CrI:A$112,300-122,000) in cohorts offered vaccination [Indicative willingness-to-pay threshold: A$50,000/LYS].

CONCLUSIONS

In primary HPV screening programs, partial genotyping for HPV16/18 or high-grade triage cytology in OHR HPV positive women can be used to refer the highest risk group to colposcopy, but 12-month follow-up for women with OHR HPV and low-grade cytology is associated with a low risk of developing cervical cancer. Direct referral to colposcopy for this group would be associated with a substantial increase in colposcopy referrals and the associated harms, and is also cost-ineffective; thus, 12-month surveillance for women with OHR HPV and low-grade cytology provides the best balance between benefits, harms and cost-effectiveness.