The clinical utility of measuring total PSA, PSA density, gamma-seminoprotein and gamma-seminoprotein/total PSA in prostate cancer prediction

Background: To evaluate whether serum total prostate-specific antigen (PSA) , PSA density (serum total PSA level divided by prostate volume), gamma -se minoprotein and gamma -seminoprotein/total PSA ratio could predict prostate cancer (PCa) prior to biopsy. Methods: A total of 316 consecutive patients who had undergone transrectal prostate biopsy and/or transurethral resection were examined. The prostate volume was determined by transrectal ultrasonography (TRUS) and the ability of the above-mentioned four variables to distinguish PCa from benign prost atic hyperplasia (BPH) was evaluated. Results: PCa was detected in 61 cases. Receiver-operating characteristic (R OC) analysis revealed that both the PSA density and serum total PSA were th e most useful predictors of PCa among the four variables. For the patients with a serum total PSA level of 4.1-10.0 ng/ml, PSA density was significant ly more accurate than total PSA (p < 0.005). An optimum PSA density value o f 0.18 was chosen as a cutoff because it showed the highest sum of sensitiv ity and specificity, 92 and 54%, respectively. Using this PSA density cutof f, the number of biopsies could have been reduced to 57 from 63% when compa red with a PSA density of 0.15. Conclusions: PSA density was significantly more accurate than other variabl es in predicting PCa, To avoid unnecessary biopsies, the PSA density cutoff value of 0.18 would be recommendable for determining a prostate biopsy for Japanese males with a serum total PSA level of 4.1-10.0 ng/ml.