The use of clinical parameters in an interactive statistical package to predict pathological features associated with local failure after radical prostatectomy for prostate cancer

Abstract

The capability of an interactive statistical package (ISP) to predict the patients whose pathologic findings at the time of radical prostatectomy for prostate cancer would require postoperative radiation therapy to prevent local failure is investigated. A retrospective review of the clinical pretreatment factors and pathologic findings of 174 patients with adenocarcinoma of the prostate treated from 1989 to 1993 with radical retropubic prostatectomy was performed and served as a knowledge base of the ISP. The pathologic findings of seminal vesicle involvement, gross transcapsular disease, and positive surgical margins are defined as outcomes associated with a high risk of local failure after radical prostatectomy and, thereby, requiring postoperative radiation therapy to decrease this risk. By using the pretreatment clinical factors including prostate-specific antigen (PSA), Gleason score, clinical stage, and endorectal magnetic resonance imaging (MRI) findings as input to the ISP, patients are identified from a test group of 50 cases with known pathologic outcome who would require postoperative radiotherapy to decrease local failure. Low- (0% to 33%), intermediate- (34% to 67%), and high-risk groups (68% to 100%) for pathologic features associated with local failure were predicted accurately (r > .95) by the ISP for the 50 test cases. Factors identified on univariate analysis by the ISP as significant predictors of local failure postoperatively include PSA > 20 (p < .001), clinical stage (p < .001), MRI finding of gross transcapsular disease (p < .001), MRI finding of seminal vesicle involvement (p < .001), and Gleason score (p < .003).(ABSTRACT TRUNCATED AT 250 WORDS)