title: Prospective study of quantitation of plasma DNA levels in the diagnosis of malignant versus benign prostate disease.
abstract: OBJECTIVE
  The aim of this study was to determine the potential of cell-free DNA levels as a diagnostic marker for prostate cancer, having first established the effect that blood sample processing has on this measurement.
  
  
  METHODS
  A total of 152 blood samples were collected prospectively from patients before their prostate biopsy and 25 from men in two distinct control groups. Blood was processed to yield three components: one-spin plasma (n = 68), two-spin plasma (n = 152), and serum (n = 56) samples.
  
  
  RESULTS
  Having established the effect of sample preparation on the measured DNA level, the more reliable two-spin plasma sample was used to determine the relationship between DNA and the presence of prostate cancer. Those patients with cancer (n = 78) had a significantly higher level of DNA compared with the control groups (P < 0.0001 and P < 0.0001). However, DNA levels in patients with a benign biopsy (n = 74) were significantly higher than the 78 patients confirmed to have cancer (P = 0.02).
  
  
  CONCLUSIONS
  We conclude that the sample type used in the quantitation of cell-free DNA has an effect on the level reported. Elevated levels are present in the two-spin plasma samples of patients with prostate cancer compared with healthy controls but are not of diagnostic value during the management of prostate cancer.
authors.affiliation: Department of Urology, Royal Berkshire and Battle Hospitals, Reading, UK.
authors.forename: Jane L
authors.initials: JL
authors.lastname: Boddy
authors.forename: Shira
authors.initials: S
authors.lastname: Gal
authors.forename: Peter R
authors.initials: PR
authors.lastname: Malone
authors.forename: Adrian L
authors.initials: AL
authors.lastname: Harris
authors.forename: Jim S
authors.initials: JS
authors.lastname: Wainscoat
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002498:Centrifugation / Q000379:methods; D004247:DNA / Q000097:blood* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011469:Prostatic Diseases / Q000097:blood / Q000175:diagnosis*; D011471:Prostatic Neoplasms / Q000097:blood / Q000175:diagnosis*; D012680:Sensitivity and Specificity
chemical_list: D004247:DNA