The Clinical Significance of Prostate Specific Antigen Density as a Screening Test of Repeat Prostate Biopsy

Purpose: We analyzed the differences between the patients who were diagnosed with prostate cancer after a previous negative biopsy and the patients who were diagnosed as nodular hyperplasia by a repeat biopsy to find out the difference between the cancer group and the negative group and to identify the useful predictors of prostate cancer on repeat biopsies. Materials and Methods: 43 patients received a repeat TRUS-guided biopsy of the prostate due to the persistent elevation of PSA after a negative initial prostate biopsy. All of the patients were classified either as cancer group or negative group. We reviewed their TRUS findings, PSAV, PSAD and %fPSA. Statistical analysis was performed using the Mann-Whitney U test, Fischer’s exact test and ROC curve. Results: Prostate cancer was detected in 7 of the 43 patients (16.3%) on repeat biopsy. PSAD of prostate cancer group was higher than that of the negative biopsy group (0.38±0.16 vs. 0.21±0.13). %fPSA level of the prostate cancer group was lower than that of the negative group (9.61±2.65 vs. 19.93±10.71). However, there was no difference within PSAV statistically and no relation between the hypoechoic lesion on TRUS and the prostate cancer proven by repeat biopsy. By ROC curve, only PSAD had a significant role as a screening test of repeat prostate biopsy. Conclusions: Based on our study, only PSAD is an effective test for screening prostate cancer on repeat prostate biopsy. We suggest that the ideal cutoff value of PSAD is 0.20 instead of 0.15.