Free/total PSA ratio does not improve prediction of pathologic stage and biochemical recurrence after radical prostatectomy.

Objectives: Despite several publications, the ability of the free/total (F/T) prostate-specific antigen (PSA) ratio to predict the pathologic extension of prostate cancer is still a matter of controversy. In addition, its ability to predict biochemical recurrence after radical prostatectomy has not yet been reported.

Methods: Since January 6, 1996, the F/T PSA ratio was prospectively measured preoperatively in 343 patients undergoing radical prostatectomy as the first treatment for localized prostate cancer.

Results: The ability to predict organ-confined disease was measured by receiver operating characteristic analysis. The areas under the curve were 0.66 for PSA density, 0.61 for total PSA, 0.60 for Gleason score, and 0.587 for the F/T PSA ratio. In multiple logistic regression analyses, the F/T PSA ratio was not a relevant predictor of organ-confined disease (Wald statistic 0.345 for P = 0.55). Similar results were obtained in the subgroup of patients with a PSA level between 2.5 and 10 ng/mL. The biochemical survival for the 270 patients who did not receive adjuvant therapy was 86% at 61 months. Statistically significant univariate predictors (P <0.05) of PSA recurrence were pT stage (log-rank 18.2) and Gleason grade (log-rank 8.8). The F/T PSA ratio was not a significant predictor of recurrence in the univariate analysis (log-rank 3.6 for P = 0.314) and in multivariate analysis (Wald statistic 0.2 for P = 0.97).

Conclusions: These results suggest that the F/T PSA ratio is not helpful for the prediction of organ-confined disease and PSA recurrence after radical prostatectomy.