PCA3 score accuracy in diagnosing prostate cancer at repeat biopsy: our experience in 177 patients.

INTRODUCTION: To evaluate PCA3 score accuracy in prostate cancer (PCa) diagnosis in patients undergoing repeat saturation prostate biopsy (SPBx).

MATERIAL AND METHODS: From January 2010 to March 2012, 177 patients (median 64 years) with primary negative extended biopsy underwent a SPBx (median 28 cores) for persistent suspicion of PCa. The indications for repeat biopsy were: PSA > 10 ng/mL, PSA values between 4.1-10 or 2.6-4 ng/mL with free/total PSA < 25% and < 20%, respectively; moreover, before performing SPBx PCA3 score was evaluated.

RESULTS: Median PSA was 9.5 ng/mL (range: 3.7-28 ng/mL): in 74 (41.8%) cases PSA was > 10 ng/mL, in 99 (56%) and 4 (2.2%) was included between 4-10 and 2.6-4 ng/mL, respectively. Median PCA3 score was equal to 52 (range 3-273); 140 (79%) and 100 (56.5%) patients had a PCA3 score greater than 20 and 35, respectively. A T1c PCa was found in 48 patients (27.1%); PCA3 score was 60 (median; range: 7-208) in the presence of PCa and 34 (median; range: 3-268) in the absence of cancer (p < 0.05). Diagnostic accuracy, sensitivity, specificity, PPV and NPV of PCA3 score cut-off of 20 vs. 35 in PCa diagnosis were 43.5 vs. 50.2%, 91.7 vs. 73%, 25.6 vs. 41.8%, 31.5 vs. 35% and 89.5 vs. 80.6%, respectively.

CONCLUSIONS: PCA3 score reduce number of unnecessary repeat SPBx; using a PCA3 cut-off of 20 vs 35 would have avoided 21% vs. 37.8% of biopsies while missing 8.4% (4 cases) vs. 27% (13 cases) of significant PCa, respectively.