Diagnostic value of urine-based PCA3 score in prostate cancer patients undergoing initial prostatic biopsy / 军事医学

ABSTRACT

Objective To evaluate the diagnostic value of urine-based prostate cancer antigen 3 ( PCA3 ) score in detecting prostate cancer during initial prostatic biopsy .Methods Urine was collected after digital rectal examination ( DRE) ( three strokes per lobe ) from 248 men before prostate biopsy .The specimens were collected between January 2010 and December 2012.The expression of PCA3 mRNA and prostate specifc antigen (PSA) mRNA was determined by quanti-tative real time polymerase chain reaction ( qRT-PCR ) .PCA3 scores were calculated by PCA 3 mRNA/PSA mRNA × 1000 .The ability of the PCA3 score to predict the biopsy outcome was assessed with AUC-ROC analysis and compared with the serum PSA levels.Results The rate of positive prostate biopsy was 32.3%(80 patients with positive prostatic biopsy versus 168 patients with negative prostate biopsy ) .PCA3 scores were significantly higher in patients with positive biopsy than in those with negative biopsy results (P<0.001).The ROC curve analysis demonstrated that the area under the ROC curve (AUC) of serum total PSA (tPSA), PCA3 score and the duplex model combining tPSA and PCA 3 score was 0.620, 0.693 and 0.724, respectively.Further analysis of the diagnostic performance of PCA3 score revealed that at a cut-off of 90.2456, the sensitivity was 67.5%and the specificity was 61.9%for discriminating positive biopsy from negative biopsy. The duplex model combining tPSA and PCA 3 score represented a better approach than tPSA alone in PCa diagnosis by pros-tatic biopsy (P=0.011), but there was no statistically significant difference between tPSA and PCA 3 score (P=0.160). In addition , a comprehensive diagnostic model based on multiple risk factors of prostate cancer combined with PCA 3 score could further improve the predictive accuracy of prostate cancer .Conclusion PCA3 could be a good predictor of prostate cancer in initial prostate biopsy in Chinese population .The comprehensive diagnostic model can improve the diagnostic potency .Further large-scale multicenter studies in China are needed to confirm our findings .