Prospective study of quantitation of plasma DNA levels in the diagnosis of malignant versus benign prostate disease.
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.
Boddy
Jane L
JL
Department of Urology, Royal Berkshire and Battle Hospitals, Reading, UK.
Gal
Shira
S
Malone
Peter R
PR
Harris
Adrian L
AL
Wainscoat
Jim S
JS
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
D004247:DNA