Does robot-assisted radical prostatectomy benefit patients with prostate cancer and bone oligometastases?

OBJECTIVE: To investigate the peri-operative and oncological outcomes of robot-assisted radical prostatectomy (RARP) in patients with oligometastatic prostate cancer (PCa). PATIENTS AND METHODS: We retrospectively reviewed the records of 79 patients with oligometastatic PCa treated with RARP or androgen deprivation therapy (ADT) between 2005 and 2015 at our institution. Of these 79 patients, 38 were treated with RARP and 41 were treated with ADT without local therapy. Oligometastatic disease was defined as the presence of five or fewer hot spots detected by preoperative bone scan. We evaluated peri-operative outcomes, progression-free survival (PFS), and cancer-specific survival (CSS). We analysed data using Kaplan-Meier methods, with log-rank tests and multivariate Cox regression models.
RESULTS: Patients treated with RARP experienced similar postoperative complications to those previously reported in RP-treated patients, and fewer urinary complications than ADT-treated patients. PFS and CSS were longer in RARP-treated compared with ADT-treated patients (median PFS: 75 vs 28 months, P = 0.008; median CSS: not reached vs 40 months, P = 0.002). Multivariate analysis further identified RARP as a significant predictor of PFS and CSS (PFS: hazard ratio [HR] 0.388, P = 0.003; CSS: HR 0.264, P = 0.004).
CONCLUSIONS: We showed that RARP in the setting of oligometastatic PCa is a safe and feasible procedure which improves oncological outcomes in terms of PFS and CSS. In addition, our data suggest that RARP effectively prevents urinary tract complications from PCa. The study highlights results from expert surgeons and highly selected patients that cannot be extrapolated to all patients with oligometastatic PCa; to confirm our findings, large, prospective, multicentre studies are required.