Predictive factors and the important role of detectable prostatic specific antigen for the detection of clinical recurrence following robot-assisted radical prostatectomy.

Abstract

e567 Background: To evaluate predictive factors associated with detectable prostate-specific antigen (PSA) and clinical recurrence (CR) after robot assisted radical prostatectomy (RARP). Methods: The study included 2500 patients who were treated with RARP between 2000 and 2016. Patients were divided into two groups according to PSA value at 6 weeks after surgery: undetectable PSA (PSA < 0.1 ng/dl) and PSA persistently elevated (PSA ≥ 0.1 ng/dl). Logistic regression analysis was used to evaluate association between covariates and: (1) detectable PSA, (2) CR (positive imaging during follow up) in persistently elevated PSA group. Kaplan-Meier analyses were used to assess CR and cancer-specific mortality (CSM) rates according to PSA persistence after surgery. Results: Overall, 229 patients (9.16%) experienced PSA persistence and from them, 38 (16.5%) had CR. Inside the group of detectable PSA ,146 men (63.75%) received adjuvant treatments and 44 (19.21%) salvage therapies. Gleason ≥ 7, ≥ pT3a, PSA > 10 ng/dl and positive margins were found as significant predictive factors of detectable PSA after surgery (all p < 0.001). Within patients with detectable PSA, stage ≥ pT3a (HR: 2.71; 95% CI, 1.10-6.67; p < 0.029) and to received adjuvant ADT (HR: 13.36; 95% CI, 5.18-34.48; p < 0.001) were associated with CR. CR-free survival in Gleason ≤ 6 at 3-year was 100% vs 60% for Gleason 7(4+3) and 20% for Gleason ≥ 8, (p 0.02). Men aged < 65 years had higher 3-year CR-free survival than older (35% vs 20%, p 0.05). 10-year CSM rates were higher for patients with CR (25% vs 0% no CR; p < 0.001), for men with Gleason ≥ 8 (10% at 10-y; p 0.003) and pathological stage ≥ pT3a (9% at 10-y; p 0.05). CSM rate for patients who received adjuvant ADT+ RT was 20%, 10% for men with ADT and 0% for patients without adjuvant treatment at 10-year (p 0,03). Conclusions: A detectable PSA is clearly affected by factors associated with high risk prostate cancer. Stage pT3 and adjuvant ADT have an important prognostic value in the prediction of CR. Patients with CR , Gleason ≥ 8, pathologic stage ≥ pT3 and those who are treated with adjuvant ADT+ RT must have a close monitoring due to the high rate of mortality.