Robot-assisted radical prostatectomy (RARP) produced better continence and potency rates at three months compared with laparoscopic radical prostatectomy (LRP), in a prospective randomised study from Italy.

Patients were randomised by the study team on a 1:1 basis to RARP or LRP. All procedures were performed by one surgeon who had previously carried out more than 600 LRPs and 100 RARPs.

The two groups were well matched in terms of age, (mean 64 years in both), BMI, PSA, Gleason score at biopsy, prostate volume and preoperative erectile function. Sixty patients in each arm were available for analysis at the end of the study.

Continence rates were higher in the RARP group at all time points in the study; at three months continence was 80% in the RARP group compared with 61.6% in the LRP group (P = 0.044). After one year, continence rates were 95% and 83.3% respectively (P = 0.042).

Among patients who had been potent preoperatively and were able to be treated with nerve-sparing techniques, rates of erection recovery were 80% and 54% in the RARP and LRP groups respectively (P = 0.02).

The only previously published prospective randomised trial of these techniques found that the robotic approach offered better erectile function recovery but failed to demonstrate an advantage in terms of postoperative continence rates.

This study is an important contribution to the literature on RARP, but has several limitations that must be considered.

Many of the participants had very early low-grade (i.e. low-risk) disease. The median PSA in each group was only around 6 ng/ml, and 41.7% and 58.3% of the RARP and LRP groups respectively had Gleason scores of 2-6 at biopsy. Given that studies have failed to demonstrate any improvement in outcome for men treated with radical prostatectomy versus observation in low-risk prostate cancer, it is questionable as to how many of these men should have been treated with radical surgery.

The study involved relatively small numbers of patients and all were recruited in a single centre and by one surgeon’s team. Furthermore, results for a single surgeon with significantly more laparoscopic experience than robotic again raises the question of potential bias.

Finally, operating on a significant proportion of patients with relatively low prostate volumes, low PSAs and low Gleason scores means that outcomes in terms of postoperative potency and continence are always going to look better than those in patients with higher-risk disease.

Dr Jonathan Rees

• Porpiglia F, Morra I, Chiarissi ML et al. Randomised controlled trial comparing laparoscopic and robot-assisted radical prostatectomy. Eur Urol 2013;63:606-614