Comparison of the Efficacy of Local Therapies for Localized Prostate Cancer in the Prostate-Specific Antigen Era: A Large Single-Institution Experience With Radical Prostatectomy and External-Beam Radiotherapy

Abstract

PURPOSE: To review biochemical relapse-free survival (bRFS) rates after either external-beam radiotherapy (RT) or radical prostatectomy (RP) for localized prostate cancer.PATIENTS AND METHODS: All 1,682 patients had pretreatment prostate-specific antigen (PSA) levels and biopsy Gleason scores (bGS) assigned. No adjuvant therapy was administered after local treatment. RP was the treatment in 1,054 patients (63%) and RT in 628 patients (37%). Median follow-up was 51 months (range, 1 to 134). The median follow-up for RP versus RT patients was 50.5 v 51.0 months. Biochemical relapse was considered detectable PSA levels (> 0.2 ng/mL) in RP patients and three consecutive rising PSA levels in RT patients. The analysis was repeated with a more stringent definition of biochemical control after either RP or RT—namely, reaching and maintaining a PSA level ≤ 0.5 ng/mL—and excluding patients receiving any androgen deprivation (AD).RESULTS: Eight-year bRFS rates for RP versus RT were 72% and 70%, respectively (P = .010). Multivariate analysis indicated T stage (P < .001), pretreatment PSA (P < .001), bGS (P < .001), year of therapy (P < .001), and neoadjuvant AD (P = .019) to be the only independent predictors of relapse. Age (P = .78), race (P = .29), prior transurethral resection of prostate (P = .81), and treatment modality (P = .96) were not independent predictors of treatment failure. Fifty-one percent of RP patients had favorable tumors (T1 to T2A, pretreatment PSA ≤ 10 ng/mL, bGS ≤ 7), compared with only 34% of RT patients (P < .001). Repeat analysis with a stringent definition of biochemical failure and excluding patients receiving AD indicated no impact of treatment modality on outcome.CONCLUSION: Eight-year biochemical failure rates were identical between RT and RP in any subgroup. Outcome is determined mainly by pretreatment PSA levels, bGS, clinical T stage, and, for RT patients, radiation dose.