Abstract 558: Muti-gene ARMS PCR using both cfDNA and cfRNAin the supernatant of pleural effusion achieves rapid and accuracy driver gene mutations detection

Abstract Background Pleural effusion from patients with advanced non-small cell lung cancer has been proved valuable for molecular analysis, especially when the tissue sample not available. However, simultaneous detection of multiple driver gene alterations especially the fusions is still challenging. Methods In this study, 77 patients with advanced NSCLC and pleural effusion were enrolled, 49 of whom had matched tumor tissues. Supernatants, cell sediments, and FFPE cell blocks were prepared from pleural effusion samples for detection of driver alterations by a PCR-based 9-gene mutation detection kit. Results In addition to mutations in EGFR, KRAS and HER2 detected in genomic DNA from cell sediments, FFPE cell blocks, and in cfDNA from supernatants, and fusions in ALK detected in RNA from cell sediments and FFPE cell blocks, fusions in ALK were also successfully detected in cfRNA from supernatants. Compared with matched tumor tissue, the supernatant showed the highest overall sensitivity (81.3%), with 81.5% for SNV/Indels by cfDNA and 80% for fusions by cfRNA, followed by FFPE cell blocks (71.0%) and the cell sediments (66.7%). Within the group of treatment-naïve patients or malignant cells observed in the cell sediments, supernatant showed higher overall sensitivity (89.5%, 92.3%) with both 100% for fusions. Based on the results, an optimized driver gene mutations detection procedure of pleural effusion is proposed. With the proposed procedure, an overall sensitivity 85.3% was achieved, with 82.1% for SNV/Indels and 100% for fusions. Conclusions CfDNA and cfRNA derived from pleural effusion supernatant (PES) have been successfully tested with a PCR-based multi-gene detection kit. An optimized procedure could maximize clinical value of testing pleural effusion samples and has good potential for routine clinical application. Citation Format: Xuejing Chen, Kun Li, Zichen Liu, Fei Gai, Guanshan Zhu, Shun Lu, Nanying Che. Muti-gene ARMS PCR using both cfDNA and cfRNAin the supernatant of pleural effusion achieves rapid and accuracy driver gene mutations detection [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 558.