PCR-based comprehensive genomic profiling (PCR-CGP): Feasibility from >20,000 tumor tissue specimens (TTS) and predicted impact on actionable biomarker identification versus hybrid capture (H)-CGP and plasma (P)-CGP.

Abstract

3574 Background: Tissue-based h-CGP is increasingly utilized for treatment selection in patients with advanced solid tumors but has high tumor surface area [TSA] requirements (≥25mm2 for leading commercial tests). P-CGP is recommended when tissue is insufficient for H-CGP. Here we assessed the feasibility and clinical impact on actionable biomarker identification of PCR-CGP. Methods: We performed a post-hoc, non-prespecified analysis on 21,743 consecutive subjects with advanced solid tumors who sent TTS for PCR-CGP from 5/17-12/19 as part of an ongoing observational trial at > 20 U.S. health systems (NCT03061305). PCR-CGP was performed using StrataNGS, a single-site laboratory developed test assessing all CGP biomarker classes (including microsatellite instability (MSI) status and tumor mutation burden [TMB]). We predicted actionable biomarker identification rates for PCR-CGP, H-CGP and P-CGP if applied to all U.S. patients with advanced solid tumors through incorporating population incidence, biomarker frequencies, test TSA and tumor content requirements (or cfDNA detection rates), and performance characteristics. Actionable biomarkers were the 30 in 11 tumor types from the MolDX p-CGP local coverage determination (L38043), pan-tumor NTRK fusions and MSI, and TMB in lung cancer. Results: Among TTS from 21,734 patients with advanced cancer, 20,493 (94.3%) met TSA requirements for PCR-CGP (≥2mm2) vs. 9,281 (42.7%) for H-CGP. PCR-CGP reported results for 98.0% and 95.0% of patients with large (≥25mm2 TSA) and small (2-24mm2) TS, respectively, in a median of 7 business days. Compared to 1,882 orthogonal actionable biomarker results, PCR-CGP accuracy was 96.6% and 96.5% in large and small TTS, respectively. Actionable biomarker frequency was highly correlated in PCR-CGP tested large vs. small TTS (r2= 0.99), as well as in this PCR-CGP cohort vs. a MSKCC institutional pan-cancer H-CGP cohort (r2= 0.92). If applied to all U.S. patients with advanced solid tumors, PCR-CGP has significantly greater predicted actionable biomarker identification rate (88.5%) compared to P-CGP (77.0%, N-1 chi-squared test, p < 0.0001) or H-CGP (54.3%, p < 0.0001). Conclusions: Half of TTS submitted for PCR-CGP did not meet H-CGP tissue requirements. PCR-CGP is feasible for the vast majority of patients and is predicted to expand the actionable biomarker evaluable proportion of patients with advanced solid tumors compared to H-CGP or P-CGP. Clinical trial information: NCT03061305 .

Clinical Application of Next-Generation Sequencing in Recurrent Glioblastoma

“…Queried genetic variations include predefined single nucleotide variants, multinucleotide variants, small insertions and deletions, gene fusions, exon skipping mutations, copy number changes, microsatellite instability status, and tumor mutation burdens. Predefined genomic variants, variant annotations, and testing cutoff metrics are available upon request from the Strata Oncology ® [41,42].…”