title: Circulating DNA addresses cancer monitoring in non small cell lung cancer patients for detection and capturing the dynamic changes of the disease.
abstract: OBJECTIVE
  Monitoring of key markers for lung cancer detection and tracking of acquired drug resistance is critical for the management of the disease. We aim to ascertain the value of monitoring both total cell free DNA concentrations and mutant EGFR DNA content within diverse groups of individuals most vulnerable to the disease.
  
  
  METHODS
  We proposed longitudinal monitoring of circulating DNA using digital PCR. Circulating DNA present in peripheral blood can be obtained non-invasively and provide timely disease status update. 25 heavy smokers and 50 patients undergoing TKI therapy were recruited. Peripheral blood specimens were taken at different time points and their circulating DNA were analyzed and quantified.
  
  
  RESULTS
  Significant higher concentrations of total cell free DNA were detected when compared with healthy high-risk individuals. Levels were stable throughout the treatment cycles, which makes it potentially a useful tool for patient stratification. Concurrent mutant T790M DNA detection of lung cancer patients at baseline achieved 82 % concordance with matched tissue analysis. Samples initially negative for the T790M gene mutation that became positive during treatment were corroborated with a repeat biopsy. The results showed its usefulness for serial monitoring.
  
  
  CONCLUSIONS
  Monitoring of circulating DNA addresses the need for disease detection and shows the ability to capture the dynamic changes of the disease.
authors.affiliation: Department of Diagnostic Medicine, JingMen NO.1 People's Hospital, JingMen, People's Republic of China.
authors.forename: Zhangjing
authors.initials: Z
authors.lastname: Wei
authors.affiliation: Department of Clinical Medicine, JingChu University of Technology, JingMen, People's Republic of China.
authors.forename: Nirej
authors.initials: N
authors.lastname: Shah
authors.affiliation: Department of Diagnostic Medicine, JingMen NO.1 People's Hospital, JingMen, People's Republic of China.
authors.forename: Chong
authors.initials: C
authors.lastname: Deng
authors.affiliation: Department of Diagnostic Medicine, JingMen NO.1 People's Hospital, JingMen, People's Republic of China.
authors.forename: Xuehui
authors.initials: X
authors.lastname: Xiao
authors.affiliation: Department of Diagnostic Medicine, JingMen NO.1 People's Hospital, JingMen, People's Republic of China.
authors.forename: Tenglang
authors.initials: T
authors.lastname: Zhong
authors.affiliation: Department of Neurosurgery, JingZhou Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Renmin Road 1, JingZhou, 434020 People's Republic of China.
authors.forename: Xiansong
authors.initials: X
authors.lastname: Li
keywords: Drug resistance; Non small cell lung cancer (NSCLC); T790M mutation; cfDNA; ctDNA