title: Circulating free DNA as non-invasive diagnostic biomarker for childhood solid tumors.
abstract: OBJECTIVE
  Our aims are to determine circulating free DNA (cfDNA) in childhood solid tumor patients who underwent surgical intervention and to analyze any relationships with clinical parameters.
  
  
  METHODS
  Fourty-four consenting children admitted with solid tumors between 2010 and 2014 were recruited. CfDNAs isolated from 0.5mL plasma obtained before and 1-30days after surgery were analyzed by next-generation sequencing (NGS: IonTorrent Cancer Hotspot panel) and by gene amplification analysis using a digital PCR (dPCR) platform.
  
  
  RESULTS
  Total amounts of cfDNA were 54-825ng and were significantly associated with stage of disease. In cfDNA, 15 mutations or deletions (2 ALK, 2 TP53, 1 WT1, 3 CTNNB1, 1 APC, 1 KIT, 1 RET, 1 CDNK2AT, and 3 SMARCB1) were identified. In 10 neuroblastoma suspected cases, 2 showed high copy numbers of MYCN using dPCR. The positive rate in our cohort was 36%, and all of these aberrations were detected in the original tumors. None of the aberrations were detectable in cfDNA after surgery except for three cases whose tumors remained after surgery.
  
  
  CONCLUSIONS
  These data demonstrate the feasibility and potential utility of mutation/deletion/amplification screening in cfDNA using NGS and dPCR for the detection of tumor biomarkers in children with solid tumors. These markers also have the potential utility to evaluate complete resection after surgery.
authors.affiliation: Department of Pediatric Surgery, Hiroshima University Hospital, Hiroshima 734-8551 Japan.
authors.forename: Sho
authors.initials: S
authors.lastname: Kurihara
authors.affiliation: Department of Pediatric Surgery, Hiroshima University Hospital, Hiroshima 734-8551 Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Ueda
authors.affiliation: Department of Pediatric Surgery, Hiroshima University Hospital, Hiroshima 734-8551 Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Onitake
authors.affiliation: Department of Pediatric Surgery, Hiroshima University Hospital, Hiroshima 734-8551 Japan.
authors.forename: Taijiro
authors.initials: T
authors.lastname: Sueda
authors.affiliation: Natural Science Center for Basic Research and Development (N-BARD), Hiroshima University, Hiroshima, Japan.
authors.forename: Emi
authors.initials: E
authors.lastname: Ohta
authors.affiliation: Natural Science Center for Basic Research and Development (N-BARD), Hiroshima University, Hiroshima, Japan.
authors.forename: Nagisa
authors.initials: N
authors.lastname: Morihara
authors.affiliation: Natural Science Center for Basic Research and Development (N-BARD), Hiroshima University, Hiroshima, Japan.
authors.forename: Shoko
authors.initials: S
authors.lastname: Hirano
authors.affiliation: Natural Science Center for Basic Research and Development (N-BARD), Hiroshima University, Hiroshima, Japan.
authors.forename: Fumiko
authors.initials: F
authors.lastname: Irisuna
authors.affiliation: Department of Pediatric Surgery, Hiroshima University Hospital, Hiroshima 734-8551 Japan; Natural Science Center for Basic Research and Development (N-BARD), Hiroshima University, Hiroshima, Japan. Electronic address: eiso@hiroshima-u.ac.jp.
authors.forename: Eiso
authors.initials: E
authors.lastname: Hiyama
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood*; D002648:Child; D004273:DNA, Neoplasm / Q000097:blood*; D005260:Female; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D008297:Male; D009154:Mutation; D009369:Neoplasms / Q000175:diagnosis* / Q000235:genetics
chemical_list: D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm
keywords: Cell-free DNA; Diagnosis; Malignant solid tumor; Next generation sequencing; Surgical evaluation