title: Circulating cell-free DNA in serum as a biomarker for diagnosis and prognostic prediction of colorectal cancer.
abstract: BACKGROUND
  To verify whether the concentrations and integrity index of circulating cell-free DNA (ccf-DNA) in serum may be clinically useful for the diagnosis and progression monitoring of colorectal cancer (CRC) patients.
  
  
  METHODS
  Serum samples were collected from 104 with primary CRC, 85 with operated CRC, 16 with recurrent/metastatic CRC, 63 patients with intestinal polyps and 110 normal controls. Long (247 bp) and short (115 bp) DNA fragments in serum were detected by real-time quantitative PCR by amplifying the ALU repeats (ALU-qPCR). Serum carcinoembryonic antigen (CEA) level was detected by ARCHITECT assay.
  
  
  RESULTS
  The median absolute serum ALU115 and ALU247/115 in primary CRC group was significantly higher than those in intestinal polyp and normal control groups (both P<0.0001), in recurrent/metastatic CRC was significantly higher compared with primary CRC (P=0.0021, P=0.0018) or operated CRC (P<0.0001, respectively) and during follow-up, ALU115 and ALU247/115 were increased before surgery and decreased significantly after surgery.
  
  
  CONCLUSIONS
  Combined detection of ALU115, ALU247/115 and CEA could improve the diagnostic efficiency for CRC. Serum DNA concentrations and integrity index may be valuable in early complementary diagnosis and monitoring of progression and prognosis of CRC.
authors.affiliation: Medical School of Nantong University, Nantong 226000, Jiangsu Province, China.
authors.forename: T B
authors.initials: TB
authors.lastname: Hao
authors.affiliation: Surgical Comprehensive Laboratory, Affiliated Hospital of Nantong University, Nantong 226000, Jiangsu Province, China.
authors.forename: W
authors.initials: W
authors.lastname: Shi
authors.affiliation: Surgical Comprehensive Laboratory, Affiliated Hospital of Nantong University, Nantong 226000, Jiangsu Province, China.
authors.forename: X J
authors.initials: XJ
authors.lastname: Shen
authors.affiliation: Surgical Comprehensive Laboratory, Affiliated Hospital of Nantong University, Nantong 226000, Jiangsu Province, China.
authors.forename: J
authors.initials: J
authors.lastname: Qi
authors.affiliation: Surgical Comprehensive Laboratory, Affiliated Hospital of Nantong University, Nantong 226000, Jiangsu Province, China.
authors.forename: X H
authors.initials: XH
authors.lastname: Wu
authors.affiliation: Medical School of Nantong University, Nantong 226000, Jiangsu Province, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Medical School of Nantong University, Nantong 226000, Jiangsu Province, China.
authors.forename: Y Y
authors.initials: YY
authors.lastname: Tang
authors.affiliation: 1] Surgical Comprehensive Laboratory, Affiliated Hospital of Nantong University, Nantong 226000, Jiangsu Province, China [2] Center of Laboratory Medicine, Affiliated Hospital of Nantong University, 20 Xisi Street, Nantong 226000, Jiangsu Province, China.
authors.forename: S Q
authors.initials: SQ
authors.lastname: Ju
mesh_terms: D001483:Base Sequence; D014408:Biomarkers, Tumor / Q000097:blood*; D016022:Case-Control Studies; D002474:Cell-Free System; D015179:Colorectal Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000473:pathology; D004247:DNA / Q000097:blood*; D017931:DNA Primers; D006801:Humans; D011379:Prognosis; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D014408:Biomarkers, Tumor; D017931:DNA Primers; D004247:DNA