Abstract 2292: Impact of delayed processing on cfDNA quantity and quality using STRECK cfDNA tubes: Connect Pilot Study
Authors: Bess Jazmyn , Hopkins Domonique , Mayoral Norma Diaz , Cooley Heather , de Palatis Angela , Wong David T. , Oshinsky Stephanie Weinstein , Abnet Christian , Horner Marie-Josephe , Black Amanda , Brotzman Michelle , Wyatt Kathleen , Sorbara Lynn , Young Matthew , Gaudet Mia , Wentzensen Nicolas , Williams Mickey , Karlovich Christopher , Greenbank Eric , Elashoff David , Wei Fang , Li Feng 
Published: March 2024

Abstract
Interest in cell-free DNA detection for multi-cancer early detection and tumor monitoring is growing.1 Prospective evaluations of liquid biopsy assays are critical, and knowledge gaps in standard collection and preparation practices must be addressed for adequate assay execution.2 The NCI Connect for Cancer Prevention Cohort Study (Connect) aims to study new approaches in early detection. A pilot study was conducted with the STRECK Cell-Free DNA BCT tube to determine the impact of processing time on cfDNA quantity and quality utilizing two complementary quality control assays. 4 STRECK DNA BCT tubes were drawn from 40 donors. Plasma samples were analyzed, with half processed immediately and the other half stored for five days before processing. Two QC assays were performed to compare results at the two processing time points. The Alu EFIRM assay measured Alu element concentration (copies/mL). The Cell-free DNA ScreenTape assay evaluated Qubit DNA concentration (μg/mL) and %cfDNA. Descriptive statistics and paired sample t-tests were performed to compare mean concentrations at the two processing time points, with and without identified samples with cytolysis.
Median, mean, and range were recorded for each assay measure (Table 1). A reduction in cfDNA quantity was observed at the 5-day processing time point. Five 5-day processing samples were identified with high DNA quantity and a high Alu element concentration. The five samples experienced hemolysis and clotting as a result of handling and processing at odds with standard protocol. There was a significant difference between the mean DNA quantities of the processing time points following exclusion of the five samples. There was no change in significance between the mean Alu concentration and %cfDNA following exclusion (Table 2).
Both assays successfully detected samples with high nuclear DNA, a major contaminant for cfDNA assays, and identified a reduction in cfDNA at the 5-day processing time point. Proper handling and processing procedures are necessary to avoid cell lysis and maximize cfDNA quality and yield. This pilot establishes a starting point for future evaluations of liquid biopsy tube types, processing delays, and preanalytical cfDNA quality variables.
Citation Format: Jazmyn Bess, Domonique Hopkins, Norma Diaz Mayoral, Heather Cooley, Angela de Palatis, David T. Wong, Stephanie Weinstein Oshinsky, Christian Abnet, Marie-Josephe Horner, Amanda Black, Michelle Brotzman, Kathleen Wyatt, Lynn Sorbara, Matthew Young, Mia Gaudet, Nicolas Wentzensen, Mickey Williams, Christopher Karlovich, Eric Greenbank, David Elashoff, Fang Wei, Feng Li. Impact of delayed processing on cfDNA quantity and quality using STRECK cfDNA tubes: Connect Pilot Study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2292.