Survival After Robotic-assisted Prostatectomy for Localized Prostate Cancer: An Epidemiologic Study

Backgrounds: To determine the potential survival benefit associated with robotic-assisted laparoscopic prostatectomy (RALP) compared to open radical prostatectomy (ORP) for prostate cancer.

Summary of background data: RALP has become the dominant surgical approach for localized disease in the absence of randomized clinical evidence and despite of the factor that RALP is more expensive than ORP.

Methods: We performed a cohort study involving patients who underwent RALP and ORP for localized prostate cancer at the Commission on Cancer- accredited hospitals in the United States. Overall survival was analyzed using the Kaplan-Meier method, log-rank test, Cox proportional hazards models, and propensity score-matched analyses. An interrupted time-series analysis using the surveillance, epidemiology, and end results program database was also performed.

Results: From 2010 to 2011, 37,645 patients received RALP and 12,655 patients received ORP. At a median follow-up of 60.7 months, RALP was associated with improved overall survival by both univariate [hazard ratio (HR), 0.69; P < 0.001] and multivariate analysis (HR, 0.76; P < 0.001) compared with ORP. Propensity score-matched analysis demonstrated improved 5-year all-cause mortality (3.9% vs 5.5%, HR, 0.73; P < 0.001) for RALP. The interrupted time-series analysis demonstrated the adoption of robotic surgery coincided with a systematic improvement in the 5-year cancer-specific survival rate of 0.17% (95% confidence interval, 0.06-0.25) per year after 2003 (P = 0.004 for change of trend), as compared to the time before adoption of RALP (1998-2003, annual percentage change, 0.01%; 95% confidence interval, -0.06 to 0.08). Sensitivity analysis suggested that the results from the interrupted time-series analysis were consistent with the improvement in the all-cause mortality demonstrated in the survival analysis (P = 0.87).

Conclusions: In this epidemiologic analysis, RALP was associated with a small but statistically significant improvement in 5-year all-cause mortality compared to ORP for localized prostate cancer. This is the first time in the literature to report a survival benefit with RALP. Our findings have significant quality and cost implications, and provide assurance regarding a dominant adoption of more expensive technology in the absence of randomized controlled trials.