title: Role of cell-free plasma DNA as a diagnostic marker for prostate cancer.
abstract: Recent evidence has shown elevated levels of cell-free plasma DNA in cancer patients. The aim of the present study was to quantify and compare the levels of cell-free plasma DNA in patients with prostate cancer, prostatic intraepithelial neoplasia (PIN), and benign prostatic hypertrophy (BPH) to examine if it offered a useful diagnostic test. Blood samples were obtained from 37 patients attending a clinic for prostate biopsies. Samples were taken prior to biopsy, within 1 hour of the biopsy, and then 2 weeks later. DNA was extracted using a QIAamp blood kit (Qiagen) and plasma DNA measured, in genome equivalents/milliliter plasma (GE/mL), using real-time quantitative PCR for the beta-globin gene. Prior to biopsy, plasma DNA concentration in BPH patients was 936 GE/mL (median; range: 633-2074 GE/mL), while cancer and PIN patients had significantly higher levels of DNA at 1734 GE/mL (median; range: 351-3131 GE/mL; P = 0.01) and 1780 GE/mL (median; range: 1514-2732 GE/mL; P = 0.04), respectively. Comparison of plasma DNA concentration before and after biopsy showed that 60 minutes after biopsy values were significantly higher in both BPH (1494 GE/mL; range: 613-2522 GE/mL; P = 0.029) and cancer (2758; range: 1498-5226 GE/mL; P = 0.007) patients. ROC analysis of the data indicated a sensitivity of 85% and a specificity of 73% when DNA concentration of 1000 GE/mL was taken as an indicator of malignancy or PIN. The data suggest that quantification of cell-free plasma DNA may have an important diagnostic role in distinguishing benign and malignant prostate disease.
authors.affiliation: Department of Urology, Guy's Hospital, London, England. darrell34a@hotmail.com
authors.forename: Darrell
authors.initials: D
authors.lastname: Allen
authors.forename: Asif
authors.initials: A
authors.lastname: Butt
authors.forename: Declan
authors.initials: D
authors.lastname: Cahill
authors.forename: Mike
authors.initials: M
authors.lastname: Wheeler
authors.forename: Rick
authors.initials: R
authors.lastname: Popert
authors.forename: R
authors.initials: R
authors.lastname: Swaminathan
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000473:pathology; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood*; D001706:Biopsy; D015331:Cohort Studies; D004273:DNA, Neoplasm / Q000097:blood*; D005914:Globins / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016133:Polymerase Chain Reaction; D017430:Prostate-Specific Antigen / Q000097:blood*; D011470:Prostatic Hyperplasia / Q000175:diagnosis / Q000473:pathology; D019048:Prostatic Intraepithelial Neoplasia / Q000175:diagnosis / Q000473:pathology; D011471:Prostatic Neoplasms / Q000097:blood* / Q000175:diagnosis / Q000235:genetics / Q000473:pathology; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D005914:Globins; D017430:Prostate-Specific Antigen