Benefits of early salvage therapy on oncological outcomes in high-risk prostate cancer with persistent PSA after radical prostatectomy

Background Patients with prostate-specific antigen (PSA) persistence are at the increased risk of disease progression. The aim of our study was to evaluate the impact of early salvage therapy on oncological outcomes in patients with persistent PSA after radical prostatectomy (RP). Methods Within a single tertiary centre database, we identified men with persistent (>= 0.1 ng/ml) versus undetectable (< 0.1 ng/ml) PSA 4-8 weeks after RP for high-risk prostate cancer (HRPCa). The cumulative incidence function was used to estimate cancer-specific survival (CSS) and clinical progression-free survival (CPFS). The Kaplan-Meier method was used to estimate overall survival (OS). The effects on oncological outcomes of salvage radiotherapy (SRT) +/- androgen deprivation therapy (ADT) vs. ADT monotherapy were tested in the subgroup of patients with persistent PSA. Results Of 414 consecutive patients who underwent RP for HRPC, 125 (30.2%) had persistent PSA. Estimated 10-year CPFS, CSS and OS for men with persistent vs. undetectable PSA were 63.8% vs. 93.5%, 78.5% vs. 98.3% and 54% vs. 83.2% (all p < 0.0001), respectively. In men with persistent PSA, ADT alone was associated with higher risk (hazard ratio (HR) for worse CSS (HR 3.9, p = 0.005) and OS (HR 4.7, p < 0.0001) but not for CP (HR 1.6, p = 0.2) when compared with SRT +/- ADT. Conclusion In patients who underwent RP for HRPCa, persistent PSA was associated with poor oncological outcomes. Early SRT +/- ADT resulted in significantly improved CSS and OS in men with persistent PSA comparing with early androgen deprivation monotherapy.