Prostate specific antigen velocity per prostate volume: a novel tool for prostate biopsy prediction

Abstract

Objective: To investigate whether altered prostate specific antigen (PSA) levels due to individual prostate growth may affect the PSA velocity (PSAV).

Materials and methods: Between January 2000 and December 2009, a total of 159 men with at least 2 transrectal ultrasonography (TRUS) procedures and concurrent PSA measurements underwent prostate biopsy because of suspicion of prostate cancer. We measured PSAV, prostate volume velocity (PVV), PSA density (PSAD), PSAD velocity (PSADV), and PSAV per initial volume. We then classified the total group into a prostate cancer (PC) group and non-PC group, and compared the 2 groups. We investigated which variables were exact to predict prostate biopsy using univariate and multivariate analyses, and assessed the diagnostic performance using the receiver operating characteristic (ROC) curve.

Results: PVV showed a positive correlation with initial prostate volume in the total and non-PC group; PVV showed a positive correlation with PSAV, and initial prostate volume correlated with PSAV in the non-PC group. The PC group showed smaller prostate volumes, higher PSAD, higher PSADV, higher PSAV per initial volume, and longer follow-up periods. After adjusting for confounding factors, the odds ratios of prostate cancer across the quartile of PSAVD were 1, 1.889, 3.226, and 7.125 (P for trend = .007), and PSAV per initial volume were 1, 2.924, 2.937, and 7.536 (P for trend = .031). On the ROC curve, the areas under the curves (AUC) of PSAV per initial volume were higher than for PSAV and PSADV.

Conclusion: Altered PSA levels due to individual prostate growth may affect the use of PSAV to predict prostate biopsy outcomes in follow-up.