Analytical Validation of a Pan-Cancer Next-Generation Sequencing Assay for In-House Liquid Biopsy Testing

Abstract

Liquid biopsy assays are transforming precision oncology by providing a less invasive alternative to tissue biopsies. These assays screen for tumor genetic alterations in circulating free DNA, which typically requires detecting variants at low allele frequencies and, therefore, a high sensitivity and specificity. This international, multicenter analytical performance study evaluated the Hedera Profiling 2 circulating tumor DNA test panel (HP2), a hybrid capture–based next-generation sequencing assay for the detection of somatic alterations in circulating free DNA. Covering 32 genes, HP2 enables the detection of single-nucleotide variants (SNVs), insertions and deletions (Indels), fusions, copy number variations, and microsatellite instability status from a single DNA-only workflow. The analytical performance was assessed using reference standards and a diverse cohort of 137 clinical samples precharacterized by orthogonal methods. In reference standards with variants spiked in at 0.5% allele frequency, sensitivity and specificity were 96.92% and 99.67%, respectively, for SNVs/Indels and 100% for fusions. In clinical samples, SNV/Indel detection showed high concordance (94% for European Society for Medical Oncology Scale of Clinical Actionability for Molecular Targets level I variants) with orthogonal methods. Evidence for solid sensitivity was also found for copy number variation detection and microsatellite instability status determination. Overall, the HP2 assay showed significant potential as a sensitive and efficient pan-cancer test for liquid biopsy testing in a decentralized molecular pathology laboratory setting.