Prognostication in Lymph Node-Positive Prostate Cancer with No PSA Persistence After Radical Prostatectomy

Background This study aimed to create a prognostic model to predict disease recurrence among patients with lymph node involvement but no prostate-specific antigen (PSA) persistence and to explore its clinical utility. Methods The study analyzed patients with lymph node involvement after pelvic lymph node dissection with radical prostatectomy in whom no PSA persistence was observed between 2006 and 2019 at 33 institutions. Prognostic factors for recurrence-free survival (RFS) were analyzed by the Cox proportional hazards model. Results Among 231 patients, 127 experienced disease recurrence. The factors prognostic for RFS were PSA level at diagnosis (≥ 20 vs. < 20 ng/mL: hazard ratio [HR], 1.66; 95% confidence interval [CI], 1.09–2.52; P = 0.017), International Society of Urological Pathology grade group at radical prostatectomy (RP) specimen (group ≥ 4 vs. ≤ 3: HR, 1.63; 95% CI 1.12–2.37; P = 0.010), pathologic T-stage (pT3b/4 vs. pT2/3a: HR, 1.70; 95% CI 1.20–2.42; P = 0.0031), and surgical margin status (positive vs. negative: HR, 1.60; 95% CI 1.13–2.28; P = 0.0086). The prognostic model using four parameters were associated with RFS and metastasis-free survival. Conclusion The prognostic model in combination with postoperative PSA value and number of lymph nodes is clinically useful for discussing treatment choice with patients.