Revisiting prostate specific antigen density (PSAD): a prospective analysis in predicting the histology of prostate biopsy

This investigation evaluated use of prostate specific antigen density (PSAD) prior to prostatic biopsy to predict prostate cancer (PCa) diagnosis and enables enhanced patient selection for prostatic biopsy. A total of 286 consecutive patients who underwent transrectal ultrasound (TRUS) biopsy of the prostate for prostate specific antigen (PSA) between 4.01 and 30.0 ng/ml were recruited to this study. Histology reports were correlated with the digital rectal examination (DRE) findings, TRUS volume, PSA levels and PSAD. In this study population, only 33 cases (11.5%) had PCa. Detection rates were 8.6%, 16.2% and 23.8% in the PSA range of 4.01-10.00 ng/ml, 10.01-20.00 ng/ml and 20.01-30.00 ng/ml, respectively. The best sensitivity (78.8%) and specificity (51.0%) for PSAD were obtained at a cut-off of 0.19 at which 136 biopsies were potentially avoidable (significant at p=0.005) and 7 may have been missed. In combination with abnormal DRE, it was possible to reduce the number of missed cancers to 3 by sparing 91 biopsies. PSA levels give the best statistical parameters at 7.00 ng/ml. Prostate volume and abnormal DRE were poor independent tests for PCa histology. A PSAD level > 0.19 in combination with an abnormal DRE improves patient selection for TRUS biopsy.