Clinical Utility of Reflex Testing with Cancer Biomarkers to Improve Diagnostic Accuracy of Primary Human Papillomavirus Screening.

Abstract

Human papillomavirus (HPV) testing is the cornerstone of cervical cancer screening, with outstanding sensitivity but only moderate specificity. We evaluated whether reflex testing for cancer biomarkers improves the sensitivity/specificity balance of screening. Cervical samples from women in Cape Town, South Africa, ages 30-65 years, were collected and tested with Xpert HPV and with real-time PCR to detect mRNA for cyclin-dependent kinase inhibitor 2A (CDKN2A), topoisomerase 2 alpha (TOP2A), and Ki67 (MKi67). Women with histologically confirmed cervical intraepithelial neoplasia grade 2 or worse (CIN2+; 85 women without and 166 with HIV) and women with no cervical disease (331 without and 257 with HIV) were included. When used as reflex tests after a positive HPV result, biomarkers discriminated well between women with and without CIN2+. The inclusion of both CDKN2A and MKi67 had the best performance, with area under the curve (AUC) of 0.9171 and 0.8734 in women without and with HIV, respectively. Although excellent, these performance parameters did not improve on an approach utilizing only HPV testing with more stringent cycle threshold cutoffs and HPV genotype selection, which achieved AUC of 0.9059 and 0.8705 in women without and with HIV, respectively. Biomarkers can be used as triage after positive HPV results but do not outperform an approach utilizing higher viral load cutoffs on selected high-risk genotypes. A screening approach using HPV testing alone can be more easily implemented at the point of care.