Oncologic Outcomes After Robot-assisted Radical Prostatectomy: A Large European Single-centre Cohort with Median 10-Year Follow-up

Abstract

Background: Robot-assisted radical prostatectomy (RARP) for prostate cancer (PCa) treatment has been widely adopted with limited evidence for long-term (>5 yr) oncologic efficacy.

Objective: To evaluate long-term oncologic outcomes following RARP.

Design, setting, and participants: Prospective cohort study of 885 patients who underwent RARP as monotherapy for PCa between 2002 and 2006 in a single European centre and followed up until 2016.

Intervention: RARP as monotherapy.

Outcome measurements and statistical analysis: Biochemical recurrence (BCR)-free survival (BCRFS), salvage therapy (ST)-free survival (STFS), prostate cancer-specific survival (CSS), and overall survival (OS) were estimated using the Kaplan-Meier method, and event-time distributions were compared using the log-rank test. Variables predictive of BCR and ST were identified using Cox proportional hazards models.

Results and limitations: We identified 167 BCRs, 110 STs, 16 PCa-related deaths, and 51 deaths from other/unknown causes. BCRFS, STFS, CSS, and OS rates were 81.8%, 87.5%, 98.5%, and 93.0%, respectively, at median follow-up of 10.5 yr. On multivariable analysis, the strongest independent predictors of both BCR and ST were preoperative Gleason score, pathological T stage, positive surgical margins (PSMs), and preoperative prostate-specific antigen. PSM >3mm/multifocal but not ≤3mm independently affected the risk of both BCR and ST. Study limitations include a lack of centralised histopathologic reporting, lymph node and post-operative tumour volume data in a historical cohort, and patient-reported outcomes.

Conclusions: RARP appears to confer effective long-term oncologic efficacy. The risk of BCR or ST is unaffected by ≤3mm PSM, but further follow-up is required to determine any impact on CSS.

Patient summary: Robot-assisted surgery for prostate cancer is effective 10 yr after treatment. Very small (<3mm) amounts of cancer at the cut edge of the prostate do not appear to impact on recurrence risk and the need for additional treatment, but it is not yet known whether this affects the risk of death from prostate cancer.

Keywords: Prostate cancer; Prostatectomy; Recurrence; Robot-assisted surgery; Salvage therapy.