Serum free circulating DNA is a useful biomarker to distinguish benign versus malignant prostate disease

Cancer Epidemiol Biomarkers Prev. 2010 Aug;19(8):1984-91. doi: 10.1158/1055-9965.EPI-10-0287. Epub 2010 Jul 20.

Abstract

Background: Free circulating DNA (fcDNA) has been shown to be elevated in serum of prostate cancer patients compared with benign controls. However, studies evaluating the role of fcDNA as a biomarker in a "representative" patient group who have undergone prostate cancer screening are lacking. Our study examined the use of serum fcDNA levels as a biomarker of prostate cancer in such a setting.

Methods: The study included 252 men, with prostate-specific antigen (PSA) levels >4 ng/mL and/or abnormal digital rectal exam. fcDNA levels in serum before prostate biopsy were quantitated by real-time PCR amplification of the glutathione S-transferase, pi, gene.

Results: Patients with PSA < or = 10 ng/mL with fcDNA > 180 ng/mL were at increased risk for prostate cancer compared with those with fcDNA < or =180 ng/mL (odds ratio, 4.27; 95% confidence interval, 2.05-8.88; P < 0.001; area under the curve, 0.742). The multivariate model including age, race, PSA, fcDNA, and interaction between fcDNA and PSA yielded a high negative predictive value of 93.1% and increased specificity of 33.1% compared with negative predictive value of 73.3% and specificity of 6.7% in the model excluding fcDNA.

Conclusions: Our results indicate that fcDNA may improve the specificity of prostate cancer screening.

Impact: Our study shows that adding fcDNA to prostate cancer screening can reduce the number of unnecessary prostate biopsies.

Publication types

  • Research Support, N.I.H., Intramural

MeSH terms

  • Aged
  • Biomarkers, Tumor / blood*
  • Biopsy / statistics & numerical data
  • DNA / blood*
  • Early Detection of Cancer
  • Humans
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Prostate / pathology
  • Prostate-Specific Antigen / blood
  • Prostatic Neoplasms / blood*
  • Prostatic Neoplasms / pathology
  • Risk
  • Sensitivity and Specificity

Substances

  • Biomarkers, Tumor
  • DNA
  • Prostate-Specific Antigen