Undetectable PSA after radical prostatectomy is more likely in low burden N+ prostate cancer patients when an extended lymph node dissection is performed

Abstract

ObjectivesTo analyze the likelihood of undetectable PSA (<0.01 ng/mL) after extended (ePLND) versus standard pelvic lymph-nodes dissection (sPLND) in pN+ patients. Materials and MethodsThe institutional prospectively maintained Prostate Cancer Database was queried for patients who underwent radical prostatectomy with PLND and were found with three or less lymph-nodal metastases between 2007 and 2017. The extension of the PLND was defined according to the number of lymph-nodes (LN) removed. Patients in the 75th or higher percentile of lymph-nodes removed were considered as the ePLND group; patients in the 25th or lower percentile in the sPLND group. Groups were compared in clinical and pathological variables. Student t-test was used for comparing continuous variables; chi-square test was used for categorical variables. Multivariable logistic regression assessed the probability of undetectable PSA at 3rd month postoperatively. Kaplan–Meier method estimated the probability of biochemical recurrence. Differences between the groups were compared by Log-rank test. Results1478 patients were treated within the time span considered. 95 with 1–3 lymph-nodal metastases were extracted. After accounting for inclusion criteria, 23 patients with a median of 11 L N removed were included in the sPLND group (25th percentile); 23 patients with >27 L N were included in ePLND group (75th percentile). Surgical time was longer for ePLND. Sixteen patients (69.6%) who underwent ePLND had undetectable PSA postoperatively. At multivariable analysis, the probability of undetectable PSA at 3rd month was higher in patients who received an ePLND (HR = 5.18; IC95% = 1.16–23.11; p = 0.03). ConclusionsePLND is more likely to predict undetectable PSA at third month after radical prostatectomy, irrespective of disease characteristics.