title: Quantification of concentration and assessment of EGFR mutation in circulating DNA.
abstract: BACKGROUND
  Analysis of circulating cell-free DNA in blood is considered as a liquid biopsy, which enables non-invasive and repetitive investigation of the tumor DNA. The potential clinical usefulness of circulating DNA is frequently examined in lung cancer. Thus, our aim was assessment if chemotherapy influences the circulating DNA concentration.
  
  
  METHODS
  Fifty-seven lung cancer patients in advanced stages of the disease were examined. Quantification of circulating DNA was determined by TERT amplification.
  
  
  RESULTS
  Distant metastases and chemotherapy were significantly connected with circulating DNA level. Patients treated with conventional chemotherapy had statistically lower circulating DNA levels when compared to patients not treated with chemotherapy. Histological types of tumor and smoking status were not associated with circulating DNA concentration. In this study, we have also genotyped the EGFR mutations in exon 19 of circulating DNA using the TaqMan PCR assays. One patient carried a deletion (2235-49del in EGFR), which has been confirmed by sequencing.
  
  
  CONCLUSIONS
  Circulating DNA is easy to obtain, convenient biological material, although quantitative analysis cannot be used as diagnostic tool, but it can be applied to determination of EGFR mutations, basis of the tyrosine kinase inhibitors application.
authors.affiliation: Center for Translational Research and Molecular Biology of Cancer, Maria Skƚodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Mazurek
authors.affiliation: Center for Translational Research and Molecular Biology of Cancer, Maria Skƚodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Pierzyna
authors.affiliation: II Radiotherapy Clinic and Teaching Hospital, Maria Skƚodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Giglok
authors.affiliation: II Radiotherapy Clinic and Teaching Hospital, Maria Skƚodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice, Poland.
authors.forename: Urszula
authors.initials: U
authors.lastname: Dworzecka
authors.affiliation: II Radiotherapy Clinic and Teaching Hospital, Maria Skƚodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice, Poland.
authors.forename: Rafa
authors.initials: R
authors.lastname: Suwiński
authors.affiliation: Center for Translational Research and Molecular Biology of Cancer, Maria Skƚodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Ma Usecka
mesh_terms: D004273:DNA, Neoplasm / Q000097:blood* / Q000235:genetics; D066246:ErbB Receptors / Q000097:blood* / Q000235:genetics; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood* / Q000188:drug therapy / Q000473:pathology; D008297:Male; D009154:Mutation; D047428:Protein Kinase Inhibitors / Q000008:administration & dosage
chemical_list: D004273:DNA, Neoplasm; D047428:Protein Kinase Inhibitors; C512478:EGFR protein, human; D066246:ErbB Receptors
keywords: Circulating DNA; cell-free DNA; chemotherapy; liquid biopsy; lung cancer