Clinical utility of the percentage of positive prostate biopsies in defining biochemical outcome after radical prostatectomy for patients with clinically localized prostate cancer

Purpose: To determine the clinical utility of the percentage of positive pr ostate biopsies in predicting prostate-specific antigen (PSA) outcome after radical prostatectomy (RP) for men with PSA-detected or clinically palpabl e prostate cancer. Methods: A Cox regression multivariable analysis was used to determine whet her the percentage of positive prostate biopsies provided clinically releva nt information about PSA outcome after RP in 960 men while accounting for t he previously established risk groups that are defined according to pretrea tment PSA level, biopsy Gleason score, and the 1992 American Joint Committe e on Cancer (AJCC) clinical T stage, The findings were then tested using an independent surgical database that included data for 823 men. Results: Controlling for the known prognostic factors, the percentage of po sitive prostate biopsies added clinically significant information (P < .000 1) regarding time to PSA failure after RP. Specifically, 80% of the patient s in the intermediate-risk group (1992 AJCC T2b, or biopsy Gleason 7 or PSA > 10 ng/mL and less than or equal to 20 ng/mL) could be classified into ei ther an 11% or 86% 4-year PSA control cohort using the preoperative prostat e biopsy dare. These findings were validated in the intermediate-risk patie nts using an independent surgical data set. Conclusion: The validated stratification of PSA outcome after RP using the percentage of positive prostate biopsies in intermediate-risk patients is c linically significant. This information can be used to identify men with ne wly diagnosed and clinically localized prostate cancer who are at high risk for early (less than or equal to 2 years) PSA failure and, therefore, may benefit from the use of adjuvant therapy, (C) 2000 by American Society of C linical Oncology.