Prostate specific antigen (PSA) persistence 6 weeks after radical prostatectomy and pelvic lymph node dissection as predictive factor of radiographic progression in node-positive prostate cancer patients

Purpose: To evaluate the prognostic value of early postoperative prostate specific antigen (PSA) levels after radical prostatectomy (RP) and pelvic lymph node dissection (PLND) in prostate cancer patients with lymph node invasion (LNI). Materials and Methods: The retrospective analysis involved 96 patients who had a diagnosis of LNI with available data on the first PSA level at postoperative 6 weeks after RP and PLND between 2002 and 2014 at our institution. PSA persistence was defined as PSA ≥ 0.1 ng/ml at 6 weeks after surgery. Radiographic progression was defined as positive imaging during follow-up after the onset of biochemical recurrence, consisting of a bone scan and/or computed tomography (CT) and/or magnetic resonance imaging and/or 18F-(2-deoxy-2-fluoro-D-glucose positron emission tomography/CT scan. Comparative analysis of patients with and without PSA persistence was done, and Kaplan-Meier curve analysis with log-rank test and Cox proportional hazard regression models assessed radiographic progression free survival (PFS). Results: Fifty two (54.2%) patients displayed PSA persistence. Kaplan-Meier curve analysis showed significantly decreased 5-year radiographic PFS (64.2% vs. 93.2%, log-rank, p=0.009) in the PSA persistence group compared to the no PSA persistence group. In a multivariate analysis, PSA persistence was a statistically significant predictor of radiographic PFS. Conclusions: Early assessment of PSA after surgery is important for predicting radiographic progression in node-positive prostate cancer patients. Risk stratification based on the early PSA value after surgery would be helpful to identify patients who may benefit from early adjuvant therapies.