Objectives: To evaluate the association between the preoperative prostate-specific antigen (PSA) level and the interval to biochemical progression after radical retropubic prostatectomy (RRP) for prostate cancer.
Methods: We studied 5534 men who underwent RRP for prostate cancer during a 15-year period and were enrolled in prospective follow-up studies. Of these men, 857 (15%) subsequently had biochemical evidence of cancer progression (PSA greater than 0.2 ng/mL). All men with biochemical progression after RRP were arbitrarily stratified into five groups according to their preoperative PSA level: less than 2.6 ng/mL, 2.6 to 4 ng/mL, 4.1 to 10 ng/mL, 10.1 to 20 ng/mL, and greater than 20 ng/mL. The time to biochemical progression after RRP was the primary endpoint of the analysis. Other prognostic factors were also evaluated in multivariable analysis.
Results: The median time to progression for men with a PSA level greater than 20 ng/mL was significantly shorter (16 months) than for men with a PSA level of 10.1 to 20 ng/mL (27 months) or those with lower PSA levels (P = 0.0005). Men with a PSA level of 4.1 to 10 ng/mL did not have a statistically significantly different median time to progression (31 months) from men with a PSA level of 10.1 to 20 ng/mL (27 months; P = 0.3), 2.6 to 4 ng/mL (32 months; P = 0.8), or less than 2.6 ng/mL (38 months; P = 0.3). Also, no statistically significant difference was found in the median time to progression between men with a PSA level of 2.6 to 4 ng/mL and less than 2.6 ng/mL (P = 0.4). In an analysis of covariance multivariate analysis, the preoperative PSA level was not an independent predictor of the time to biochemical progression (P = 0.12), after accounting for tumor stage and Gleason grade.
Conclusions: The preoperative PSA level was significantly associated with the interval to biochemical cancer progression after RRP; however, this association appeared to be because the preoperative PSA level serves as a surrogate marker for other prognostic factors, such as the tumor volume, tumor stage, and Gleason grade.