Impact of the introduction of a robotic training programme on prostate cancer stage migration at a single tertiary referral centre

What's known on the subject? and What does the study add? Previous studies have retrospectively compared functional and oncological outcomes between robot-assisted radical prostatectomy (RARP) and open retropubic radical prostatectomy (RRP), reporting non-inferior or superior outcomes associated with the use of the robotic approach. The study demonstrates that baseline selection biases makes comparisons of RARP and RRP problematic. Patients treated with RARP may have significantly better baseline characteristics than patients treated with RRP. Indeed, when both facilities are available within the same centre, patients with the most favourable clinical and cancer profile are inherently selected to RARP. In the absence of a prospective randomized trial, the decision to prefer one approach over another should be tailored according to each single patient and surgeon. Objective To evaluate the trend in robot-assisted radical prostatectomy (RARP) and open retropubic radical prostatectomy (RRP) use over time and to compare preoperative and pathological characteristics of patients treated with RARP or RRP at a single centre. Patients and Methods Between 2006 and 2010, 2511 consecutive patients treated with RP, with or without pelvic lymph node dissection (PLND), for prostate cancer (PCa) at a single tertiary care centre were analysed. Baseline patient characteristics and PCa risk distribution were compared according to treatment type (RRP vs RARP) in the overall population, as well as in three surgeons' initial 50 RARP and three surgeons' initial 50 RRP cases (n = 300). We used a chi-squared trend test to evaluate the differences in treatment type administration over time according to PCa characteristics. Logistic regression analyses focused on the prediction of PLND and adjuvant radiotherapy (RT) use. Results Overall, 1873 (74.6%) and 638 (25.4%) patients underwent RRP and RARP, respectively. Men treated with RARP were younger (mean age: 62 vs 65 years), less obese (mean BMI: 24.8 vs 26.4kg/m2), healthier (Charlson comorbidity index = 0: 68.7 vs 53.3%) and more likely to harbour clinical low-risk PCa (51 vs 30%) than their RRP counterparts (all P < 0.001). Similar findings were observed in sub-analyses focusing on six surgeons' 50 initial patients (all P 0.02). A significant increase in the rate of patients with low-risk PCa treated with RARP vs RRP was reported over time (5 vs 95% and 66 vs 34% in 2006 and 2010, respectively). Conversely, 76% of patients with high risk PCa were still treated with RRP in 2010. Patients treated with RARP were less likely to receive PLND at RP and adjuvant RT (all P 0.01), even after adjusting for clinical and PCa characteristics. Conclusions The introduction of a robotic training programme at a high volume centre led to significant patient selection in terms of clinical and PCa characteristics. When both RRP and RARP facilities are available within the same centre, patients with the most favourable clinical and cancer profile are selected to undergo RARP. Use of RARP negatively influenced the rates and the extent of PLND as well as the use of adjuvant RT after surgery. Thus, baseline patient selection, surgical and treatment biases make any comparisons of RARP with RRP problematic.