Collaborator Presented Research Result on Small Methods Journal
Research result, CLAmp-seq: A Novel Amplicon-Based NGS Assay with Concatemer Error Correction for Improved Detection of Actionable Mutations in Plasma cfDNA from Patients with NSCLC, conducted by Professor Jiatao Lou, from Shanghai Chest Hospital, recently published on Small Methods.
The study was chaired by Professor Jiatao Lou, director of the Department of Laboratory Medicine of Shanghai Chest Hospital. It was jointly participated by Cancer Center of the First Hospital of Jilin University, Department of Radiation Oncology of Sun Yat-sen University Cancer Center, AccuraGen Inc., etc.
This study evaluated the analytical sensitivity, specificity, and limit of detection (LOD), based on the cfDNA standard materials. The panel was then used to analyze plasma cfDNA samples from 134 NSCLC cancer patients and 50 non-cancerous controls, and ctDNA-NGS results were compared with tumor tissue ARMS and cfDNA ddPCR results.
CLAmp-seq demonstrated median detection rate of 100% at allele frequency of 0.1% for 20ng of cfDNA and zero false positive in all blank control samples. In cfDNA from plasma collected before treatment, EGFR mutations detected by ctDNA-NGS was 94.8% concordant with tumor tissue ARMS-PCR. CLAmp-seq demonstrated strong per-variant detection-rate concordance (98%) and allele frequency concordance (R² = 0.95) when compared with cfDNA ddPCR result. This study also reflected the advantages of ctDNA-NGS for detection of de novo 19 Indel mutations that multiple PCR methods cannot detected fully.
Based on the fundamentals of medical testing, carefully validate the performance
The research team went back to the fundamentals of medical testing of ctDNA detection, focused on the accuracy and clinical effectiveness, and carefully validated the performance of CLAmp-seq, using a variety of methods for side-by-side comparisons to effectively consider whether the technical platform is accurate and reliable, and to further discuss the clinical value and significance of medical testing based on this platform.
This study highlights laboratory performance validation based on standard materials (sensitivity, specificity, LOD, etc.) and clinical performance validation based on clinical samples, taking into account the future detection of various clinical application situations in the real world. These research ideas, based on the perspective of laboratory medicine, are aimed to improve the standardization and repeatability of clinical verification procedures for liquid biopsy. It is expected to promote the popularization of ctDNA-NGS technology to more medical laboratories and help the development of precision medicine for oncology.
A novel amplicon-based NGS technology, with a concatemer-based error correction strategy, can offer an easy-to-use, fast, and accurate molecular diagnostic tool with multiplex capacity that is well-suited for clinical in vitro diagnosis.