Crc Mrd Detection Using Accu-Act (Tm) Ngs Technology

Circulating tumor DNA (ctDNA) is a promising biomarker for detecting minimal residual disease (MRD) and for monitoring treatment of patients with colorectal cancers (CRC). Any technology used for this purpose, however, will face extreme performance demands. In order to build a high-performance multiplex next-generation sequencing (NGS) platform suitable for cancer MRD using ctDNA, we developed Accu-Act TM , an NGS-based assay capable of detecting low-frequency variants in plasma ctDNA with high precision. In our protocol, rolling-circle amplification is used to circularize denatured double-stranded cell-free DNA (cfDNA) and convert it into long tandem repeats, thus enabling consensus-based concatemer error correction. We demonstrated Accu-Act TM ’s sensitivity and specificity by testing it on cfDNA samples with known variant frequencies and cfDNA collected from healthy individuals (n = 100). Our results showed that the sensitivity of Accu-Act was 0.1% with an error rate of 1 in 1 million for 20ng of input cfDNA. Concordance analysis was performed using Accu-Act, a 61-gene assay, on 152 tumor/plasma pairings of preoperative samples derived from patients with CRC (stage I-IV). Depending on stage, we report 66-92% patient detection rate. Post-surgery ctDNA profiling was performed on 52 patients (stage I-IV) enrolled in our prospective MRD study. The results showed that 26% of patients had detectable postoperative ctDNA, among whom 72% had disease progression within two years. Only one out of the 41 patients without detectable postoperative ctDNA went on to relapse, and one patient died of a lung infection. Our study showed that ctDNA is a promising prognostic biomarker for CRC relapse after R0 resection (HR (95%CI) 33.00 (4.05 - 270), P TM NGS-based ctDNA assay has high accuracy and is suitable for MRD in CRC patients. Accu-Act TM should make a significant contribution in the development of personalized cancer treatment. Citation Format: Xinxing Li, Grace Zhao, Xianwen Zhang, Yanping Sun, Yi Wang, Canping Ruan, Paul Tang, Malek Faham, Shengrong Lin, Kang Ying, Zhiqian Hu. CRC MRD detection using Accu-Act TM NGS technology [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr A035.