title: Microdroplet digital PCR: detection and quantitation of biomarkers in archived tissue and serial plasma samples in patients with lung cancer.
abstract: BACKGROUND
  There is much interest in the use of noninvasive biomarkers in the management of lung cancer, particularly with respect to early diagnosis and monitoring the response to intervention. Cell-free tumor DNA in patients with cancer has been shown to hold potential as a noninvasive biomarker, in which the response to treatment may be evaluated using a blood test only. Multiple technologies have been suggested as being appropriate to measure cell-free tumor DNA. Microdroplet digital polymerase chain reaction (mdPCR) has a number of attributes that suggest it may be a useful tool for detecting clinically relevant genetic events. It offers precise and accurate quantitation of mutant alleles, including rare variants.
  
  
  METHODS
  We evaluate the performance of mdPCR in the analysis of DNA extracted from reference standards, tumor biopsies, and patient plasma.
  
  
  RESULTS
  The potential of mdPCR to detect clinically relevant mutations is demonstrated, in both formalin-fixed paraffin-embedded material and plasma. Furthermore, we show that mdPCR can be used to track changes in peripheral blood biomarkers in response to treatment and to detect the emergence of drug-resistant clones.
  
  
  CONCLUSIONS
  MdPCR has potential as a tool to detect and quantify tumor-derived mutational events in cell-free DNA from patients with lung cancer.
authors: Departments of *Oncology, †Asthma, Allergy, and Lung Biology, King's College London, London, United Kingdom; ‡Guy's and St Thomas' NHS Trust, London, United Kingdom; and §Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom.
authors: Fangfei
authors: F
authors: Gao
authors: Ester
authors: E
authors: Pfeifer
authors: Hassan
authors: H
authors: Farah
authors: Elena
authors: E
authors: Karampini
authors: Divyanshu
authors: D
authors: Dua
authors: Nahid
authors: N
authors: Kamal
authors: Paul
authors: P
authors: Cane
authors: Khalid
authors: K
authors: Tobal
authors: Tariq
authors: T
authors: Sethi
authors: James
authors: J
authors: Spicer
authors: Frank
authors: F
authors: McCaughan
mesh_terms: D000230:Adenocarcinoma / Q000097:blood / Q000737:chemistry* / Q000235:genetics*; D000077192:Adenocarcinoma of Lung; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000097:blood; D004252:DNA Mutational Analysis / Q000379:methods*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood / Q000737:chemistry* / Q000235:genetics*; D008297:Male; D016133:Polymerase Chain Reaction / Q000379:methods*
chemical_list: D014408:Biomarkers, Tumor