PT - JOURNAL ARTICLE AU - KAVITHA RAMACHANDRAN AU - CARL G. SPEER AU - STEPHANIE FIDDY AU - ISILDINHA M. REIS AU - RAKESH SINGAL TI - Free Circulating DNA as a Biomarker of Prostate Cancer: Comparison of Quantitation Methods DP - 2013 Oct 01 TA - Anticancer Research PG - 4521--4529 VI - 33 IP - 10 4099 - http://ar.iiarjournals.org/content/33/10/4521.short 4100 - http://ar.iiarjournals.org/content/33/10/4521.full SO - Anticancer Res2013 Oct 01; 33 AB - Aim: To identify a simpler method of free circulating DNA (fcDNA) quantitation that may improve the specificity of the prostate cancer prostate-specific antigen (PSA) screening test. Materials and Methods: The patient group consisted of 241 men with elevated PSA/abnormal digital rectal exam (DRE), undergoing prostate biopsy. Serum fcDNA levels were measured by UV absorbance and PicoGreen. Results were compared to previously published quantitative polymerase chain reaction (qPCR) data. Results: We found that levels of fcDNA measured by PicoGreen correlated well with those measured by qPCR (r=0.8552). In the patient group with PSA >4 to 10 ng/ml, those with fcDNA (PicoGreen) >53.1 ng/ml were at increased risk for prostate cancer compared to those with fcDNA ≤53.1 ng/ml. Moreover, we found that measuring fcDNA levels by PicoGreen does not compromise the negative predictive value, accuracy or specificity of the qPCR fcDNA test. Conclusion: If validated in larger studies, PicoGreen quantitation of fcDNA could serve as a simple method to aid in prostate cancer diagnosis.