AB067. Short-term therapeutic outcomes of robotic-assisted laparoscopic radical prostatectomy (RALP) for oligometastatic prostate cancer versus non-oligometastatic prostate cancer: a propensity score matching study

BACKGROUND: To compare the short-term therapeutic outcomes of robotic-assisted laparoscopic radical prostatectomy (RALP) for oligometastatic prostate cancer (OPC) versus non-OPC by using propensity score matching. METHODS: Between April 2012 and October 2017, 508 consecutive patients underwent RALP as a first-line treatment. The patients were divided into two groups according to oligometastatic state: the non-OPC group (n=467) or the OPC group (n=41). Oligometastatic disease was defined as the presence of two or fewer hot spots apparent by bone scan, PET-CT or MRI, without the presence of visceral metastases. The association of oligometastatic state and therapeutic outcomes of RALP was evaluated, including biochemical recurrence (BCR) and overall survival (OS) by utilizing a Kaplan-Meier survival analysis. A Cox proportional hazards model was used to assess the possible risk factors of BCR. RESULTS: Matching produced 41 matched pairs of patients. In the two matched groups, cumulative BCR survival rates were 62.8% and 60.7% at 4 years, respectively, for the OPC group and non- OPC group. The OS rates were 96.3% and 100% at 5 years for the OPC group and non-OPC group, respectively. BCR (P=0.987) and OS (P=0.326) were not significantly different between the two matched groups. Additionally, the result of Cox regression showed that oligometastatic state was not an independent risk factors for BCR (P=0.6816). CONCLUSIONS: Our findings support the safety and effectiveness of RALP in OPC. Additionally, oligometastatic state did not have an adverse effect on BCR independently.