title: Cell-free DNA: measurement in various carcinomas and establishment of normal reference range.
abstract: BACKGROUND
  Cell-free DNA is detectable in circulating blood. Numerous reports in the literature have pointed out that cell-free DNA in plasma or serum has the clinical potential to be a more specific tumor marker for the diagnosis and prognosis, as well as the early detection, of cancer.
  
  
  METHODS
  In order to adapt cell-free DNA to a routine clinical laboratory test, we used commercial kits such as the QIAamp blood kit for DNA extraction and the PicoGreen DNA kit for DNA quantification. This was done so our results and the normal reference value established would allow to be compared by other laboratories. We have established the normal reference level of cell-free DNA for females and males from age 20-70 years. We also detected elevated cell-free DNA in all cancers that were tested in this study, including carcinomas, leukemia and lymphoma.
  
  
  RESULTS
  Our study indicates that the elevation of serum cell-free DNA was usually detected in specimens containing elevated tumor markers and is most likely associated with tumor metastases. The electrophoretic pattern of cell-free DNA showed that cell-free DNA from cancer patient is fragmented, containing smaller DNA (100 bp) not found in normal cell-free DNA.
  
  
  CONCLUSIONS
  Measuring cell-free DNA may complement currently used tumor markers for the management of cancer patients.
authors.affiliation: Department of Pathology, Chang Gung Memorial Hospital, Taipei, Taiwan.
authors.forename: Tsu-Lan
authors.initials: TL
authors.lastname: Wu
authors.forename: Diana
authors.initials: D
authors.lastname: Zhang
authors.forename: Ju-Hsin
authors.initials: JH
authors.lastname: Chia
authors.forename: Kuo -hien
authors.initials: K-
authors.lastname: Tsao
authors.forename: Chien-Feng
authors.initials: CF
authors.lastname: Sun
authors.forename: James T
authors.initials: JT
authors.lastname: Wu
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000097:blood; D014408:Biomarkers, Tumor / Q000097:blood*; D001943:Breast Neoplasms / Q000097:blood* / Q000175:diagnosis; D002272:Carcinoembryonic Antigen / Q000097:blood; D004247:DNA / Q000097:blood*; D004586:Electrophoresis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018396:Mucin-1 / Q000097:blood; D010051:Ovarian Neoplasms / Q000097:blood* / Q000175:diagnosis; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood* / Q000175:diagnosis; D012016:Reference Values; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; D018396:Mucin-1; D004247:DNA; D017430:Prostate-Specific Antigen