Persistent Prostate-Specific Antigen After Radical Prostatectomy and Its Impact on Oncologic Outcomes.

Background: Persistent prostate-specific antigen (PSA) represents a poor prognostic factor for recurrence after radical prostatectomy (RP).

Objective: To investigate the impact of persistent PSA at 6wk after RP on long-term oncologic outcomes and to assess patient characteristics associated with persistent PSA.

Design, Setting, And Participants: Within a high-volume center database we identified patients who harbored persistent (≥0.1ng/ml) versus undetectable PSA (<0.1ng/ml) at 6wk after RP. Patients with neo- and/or adjuvant androgen-deprivation therapy (ADT) were excluded.

Outcome Measurements And Statistical Analysis: Logistic regression models tested for prediction of persistent PSA. Kaplan-Meier analyses and Cox regression models tested the effect of persistent PSA on metastasis-free survival (MFS), overall survival (OS), and cancer-specific survival (CSS) rates. Propensity score matching (PSM) was performed to test the impact of salvage radiotherapy (SRT) on OS and CSS in patients with persistent PSA.

Results And Limitations: Of 11 604 identified patients, 8.8% (n=1025) harbored persistent PSA. At 15yr after RP, MFS, OS, and CSS were 53.0% versus 93.2% (p<0.001), 64.7% versus 81.2% (p<0.001), and 75.5% versus 96.2% (p<0.001) for persistent versus undetectable PSA, respectively. In multivariable Cox regression models, persistent PSA represented an independent predictor for metastasis (hazard ratio [HR]: 3.59, p<0.001), death (HR: 1.86, p<0.001), and cancer-specific death (HR: 3.15, p<0.001). SRT was associated with improved OS (HR: 0.37, p=0.02) and CSS (HR: 0.12, p<0.01) after 1:1 PSM. Main limitation is missing data on postoperative PSA and duration of salvage ADT.

Conclusions: Persistent PSA is associated with worse oncologic outcome after RP, namely, metastasis, death, and cancer-specific death. In patients with persistent PSA, SRT resulted in improved OS and CSS.

Patient Summary: We assessed the impact of persistent prostate-specific antigen (PSA) at 6wk after radical prostatectomy on oncologic outcomes. Early persistent PSA was associated with worse metastasis-free survival, overall survival, and cancer-specific survival. Salvage radiotherapy may result in a survival benefit in well-selected patients.