Utilizing predictions of early prostate-specific antigen failure to optimize patient selection for adjuvant systemic therapy trials

Purpose: Prostate-specific antigen (PSA)failure within 2 years after radica l prostatectomy (RP) has been shown to be a clinically significant predicto r of distant failure. This study was performed to estimate 2-year PSA failu re rates on the basis of readily available clinical and pathologic factors to identify patients for whom effective adjuvant systemic therapy is needed . Patients and Methods: A Cox regression multivariable analysis was used to d etermine whether the percentage of positive prostate biopsies, PSA level, a nd the pathologic findings at RP in 1,728 men provided clinically relevant information about PSA outcome after RP, A bootstrapping technique with 2,00 0 replications was used to provide 95% confidence intervals for the predict ed 2-year PSA failure rates, which were determined on the basis of the inde pendent clinical and pathologic predictors of PSA outcome. Results: The independent predictors of time to PSA failure included a perce ntage of positive prostate biopsies of greater than 34% (P less than or equ al to .009), PSA level greater than 10 ng/mL (P less than or equal to .01), seminal vesicle invasion (P = .02), prostatectomy Gleason score of 8 to 10 (P = .04), and positive surgical margins (P = .0001). Predictions of 2-yea r PSA failure rates and bootstrap estimates of the 95% confidence intervals ware arranged in a tabular format, stratified by independent clinical and pathologic predictors of PSA outcome. Conclusion: Patients who are most likely to benefit from effective adjuvant systemic therapy after RP can be identified using readily available clinic al and pathologic data. (C) 2000 by American Society of Clinical Oncology.