Comparison of open and robot-assisted pelvic lymphadenectomy for prostate cancer

We evaluated whether there were differences in the lymph node yield and incidence of nodal metastasis among patients undergoing robot-assisted radical prostatectomy with pelvic lymphadenectomy (LAD) and open radical retropubic prostatectomy with either a standard or extended node dissection.

Data were collected retrospectively on all patients undergoing radical prostatectomy with pelvic LAD at our institution between January 2006 and December 2008. Patients in group 1 (n = 60) underwent robot-assisted standard LAD, those in group 2 (n = 64) had open standard LAD, and group 3 patients (n = 43) were treated with open extended LAD. Statistical comparison was then made between the three groups stratified by histologic grade and pathologic stage.

The mean lymph node yield was 8.2 for group 1, 7.6 for group 2, and 14.8 for group 3. The overall incidence of positive nodes in each group was 3.3%, 1.6%, and 18.6%, respectively. There were no differences between the node counts (P = 0.84) and probability of finding positive nodes between the robot-assisted and open standard dissections. The extended LAD identified patients with positive nodes at a greater frequency, although those patients were more likely to have adverse pathologic features. Complications related to the lymphadenectomy were not different between the groups.

The lymph node yield obtained during robot-assisted pelvic lymphadenectomy for prostate cancer is comparable to an open approach using a similar template. An open extended node dissection yields more nodes and identifies a greater number of patients with lymph node involvement.