447PD - Modified ctDNA extraction method combined with blocker PCR assays improves the liquid biopsy efficiency in NSCLC patients

Date 17 December 2016
Event ESMO Asia 2016 Congress
Session Thoracic cancers
Topics Non-Small-Cell Lung Cancer, Metastatic
Translational Research
Presenter Meiling Zhang
Citation Annals of Oncology (2016) 27 (suppl_9): ix139-ix156. 10.1093/annonc/mdw594
Authors M. Zhang1, Z. Gong2, C. Li1, H. Ji1, J. Hu1, Q. Hong1, Y. Hou3, F. Huang4, W. Guo4, D. Zhang2, X. Zhang1
  • 1Department Of Pulmonary Medicine, Zhongshan Hospital, Fudan University, 200032 - Shanghai/CN
  • 2Shanghai, yunying medicine, 201216 - Shanghai/CN
  • 3Department Of Pathology, Zhongshan Hospital, Fudan University, 200032 - Shanghai/CN
  • 4Department Of Laboratory Medicine, Zhongshan Hospital, Fudan University, 200032 - Shanghai/CN



Genetic alterations detected in circulating tumor DNA(ctDNA), also known as liquid biopsy, is facing a grim challenge - its sensitivity is not high enough to identify mutations clinically. The aim of this study was to investigate the likelihood of improving liquid biopsy efficiency with modified ctDNA extraction method and blocker PCR assays.


Plasma and the matched tissues were collected to assess the concordance rate in EGFR mutation detection. ctDNA was extracted from plasma using the modified extraction method and the copy numbers was determined by standard curve. Mutations in plasma were identified by blocker PCR assays while the corresponding tissue samples were examined by amplification refractory mutation system(ARMS). Next generation sequencing (NGS) was employed to further identify mutations in plasma simultaneously to verify the reliability of the blocker PCR assays.


The plasma testing has high concordance rate of 99.06%[k = 0.97; 95% confidence interval (CI), 0.87-0.99; P 


Increasing amounts of ctDNA by modifying extraction platforms and employing highly accurate detection technologies are indispensable for the efficiency improvement of liquid biopsy. It was demonstrated that genetic alterations detected in ctDNA has high concordance rate with tumor tissue, it might indisputably partly substitute for tumor tissue EGFR detection in the near future with its minimal invasive and convenient properties.

Clinical trial indentification


Legal entity responsible for the study

Xin Zhang


Shanghai Yunying Medical Technology Co.Ltd


All authors have declared no conflicts of interest.