Optimizing patient selection for prostate monotherapy

Purpose: Patients at low risk for prostate-specific antigen (PSA) failure f ollowing definitive local therapy are those with PSA of 10 or less, biopsy Gleason Score of 6 or less, acid 1992 American Joint Committee on Cancer (A JCC) clinical Stage T1c or T2a, However, low-risk patients managed with rad ical prostatectomy and found to have prostatectomy Gleason score greater th an or equal to 3+4 have a less favorable PSA outcome when compared to patie nts with prostatectomy Gleason score less than or equal to 3+3, This study was performed to determine whether the percentage of positive prostate biop sy cores could predict upgrading from a biopsy Gleason score of 6 or less t o a prostatectomy Gleason score greater than or equal to 3+4 in low-risk pa tients to optimize selection for prostate only radiation therapy. Methods and Materials: Concordance testing of the biopsy Gleason score and the primary and secondary prostatectomy Gleason grades was performed in 427 prostate cancer patients treated with radical prostatectomy and at low ris k for PSA failure. Logistic regression multivariable analysis was performed to test the ability of the established prognostic factors and the percenta ge of positive prostate biopsies (<34%, 34-50%, >50%) to predict for upgrad ing from biopsy Gleason score of 6 or less prostatectomy Gleason score 3+4, PSA failure-free survival was reported using the actuarial method of Kapla n and Meier and comparisons were made using a log-rank test, Results: Twenty-nine percent of the 427 study patients were upgraded from a biopsy Gleason score of 6 or less to a prostatectomy Gleason score greater than or equal to 3+4, The presence of greater than 50% positive biopsies w as the only significant factor for predicting the upgrading from biopsy Gle ason score of 6 or less to prostatectomy Gleason score > 3+4 on logistic re gression multivariable analysis with the variables treated as continuous an d categorical. Specifically, upgrading occurred in 26% vs. 59% of patients with 50% or less vs. greater than 50% positive biopsies, respectively. This translated into a 5-year PSA failure-free survival which was significantly higher (92% vs, 62%,p = 0.00001) for men with 50% or less vs. greater than 50% positive prostate biopsies, respectively. Conclusion: The presence of greater than 50% positive biopsies was associat ed with higher rates of pathologic upgrading which translated into lower 5- year PSA failure-free survival following radical prostatectomy (RP), Theref ore, the percentage of positive biopsies may be useful in optimizing the se lection of low-risk patients for prostate only radiation therapy such as ex ternal beam radiation or implant monotherapy, (C) 2001 Elsevier Science Inc .