Nonrandomized single institutional comparison of radical prostatectomy, external beam radiotherapy, or permanent seed implantation in the management of localized prostate cancer

Abstract

4653 Background: We review biochemical relapse-free survival (bRFS) rates after 125I permanent seed implantation (PI), external beam radiotherapy (EBRT), or radical prostatectomy (RP) for clinical stage T1-T3 prostate cancer in a large single center cohort. Methods: The study population was selected from 3074 consecutively treated patients with clinically localized disease treated between 1996–2001. Biochemical failure was defined as a confirmed PSA >0.2 ng/ml after RP and 3 consecutive rising PSA levels (ASTRO consensus definition) after EBRT or PI. RP patients receiving adjuvant radiotherapy and all patients receiving neoadjuvant or adjuvant androgen deprivation were excluded from analysis. To eliminate the time dependency of the ASTRO definition for failure, RP patients with < 24 month follow-up and EBRT and PI patients with <48 months of follow-up were also excluded, leaving 1056 patients in the study cohort. Clinical characteristics of the study population are summarized in the table. Results: The 5-year bRFS rates for PI vs EBRT vs RP were 86%, 81%, and 81%, respectively (p=0.56). Multivariate analysis identified PSA (p<0.001) and biopsy Gleason sum (p<0.001) as independent predictors of relapse, while treatment modality (p=0.42), clinical T stage (p=0.10), age (p=0.56), and race (p=0.11) were not predictors of failure. Conclusions: Even when allowing for longer follow-up times for patients treated with either EBRT or PI to manifest biochemical failure, bRFS rates were similar between PI, EBRT and RP as monotherapy for clinically localized prostate cancer in this contemporary cohort. Outcome in these predominantly low risk patients is determined by pretreatment PSA levels and biopsy Gleason score. No significant financial relationships to disclose.