Stratification of patient risk based on prostate-specific antigen doubling time after radical retropubic prostatectomy

OBJECTIVES: To assess the risk of local recurrence, systemic progression, and death from cancer among patients who experience biochemical relapse after radical retropubic prostatectomy and to stratify those patients by prostate-specific antigen (PSA) doubling time (DT). PATIENTS AND METHODS: We identified patients who experienced biochemical recurrence (defined as a PSA level ≥0.4 ng/mL) after radical prostatectomy from January 1, 1990, to December 31, 1339, for prostate adenocarcinoma. The PSA-DT was calculated by log linear regression using all PSA values within 2 years of biochemical recurrence. Local recurrence- and systemic progression-free survival and cancer-specific survival were estimated using the Kaplan-Meler method and analyzed by the log-rank test and Cox models. RESULTS: Biochemical recurrence was noted in 1521 (27%) of 5533 men during the follow-up period. Of the 1064 patients with a calculable PSA-DT, 322 (30%) had a PSA-DT of less than 1 year, 357 (34%) had a PSA-DT of 1 to 9.9 years, and 385 (36%) had a PSA-DT of 10 years or more. Patients with a PSA-DT of 10 years or more were less likely to have a higher preoperative PSA level, Gleason score, advanced pathologic stage, and seminal vesicle invasion. Patients with a PSA-DT of 10 years or more were at low risk of local recurrence (hazard ratio [HR], 0.09; 95% confidence interval [CI], 0.06-0.14; compared with patients with a PSA-DT of <1 year), systemic progression (HR, 0.05; 95% CI, 0.02-0.13), or death from cancer (HR, 0.15; 95% CI, 0.05-0.43). CONCLUSIONS: Prostate-specific antigen DT is an independent predictor of clinical disease recurrence and mortality after surgical biochemical failure. Risk stratification into high-, intermediate-, and low-risk categories based on the PSA-DT provides helpful clinical information and assists in the development of salvage therapy trials.