EAU 2019: Comparison Between Limited and Extended Lymph Node Dissection for Prostate Cancer: Results from a Large Clinically Integrated Randomized Trial
Cluster randomization with cross over did occur and therefore each surgeon was randomized to a limited or extended pelvic lymph node dissection for a 3 month period. Limited node dissection was defined as obturator nodes compared to an extended dissection defined as an obturator, external and internal iliac nodes. The primary endpoint assessed was time to biochemical recurrence.
The randomized group had similar demographics including age, preoperative PSA, Gleason Grade, the presence of extracapsular extension, nodal disease, and seminal vesical invasion.
To summarize findings, no differences were seen in biochemical free survival comparing the limited and extended template dissection groups. When performing a subgroup analysis of patients enrolled after 2015 or a meta-analysis, no statistical differences were identified as well. Furthermore, limited templates had a median of 10-12 nodes removed per patient compared to extended templates with a median of 12-14 nodes.
Surgical biases were present however, as high-risk patients were more likely to have a greater number of lymph nodes removed whether patients were stratified to the limited or extended nodal template. Similarly, patients with higher risk disease were less likely to be enrolled in the study overall. Evaluating morbidity, no grade 4-5 complications were present in either arm and low grade (2-3) compilations were present in equal amounts in limited and extended dissection (11-12%).
In summary, Dr. Touijer stated that extended pelvic lymph node dissection did not improve freedom from biochemical recurrence compared to the limited template. However, the small differences in nodal counts and positivity suggested the differences between the randomized groups were small and significant surgical biases were present.
It will be interesting to assess if any differences were present in the various surgical approaches (open, laparoscopic, and robotic) and to sub-analyze patients by D’Amico risk cohorts. For now, surgeons should mainly utilize extended templates for high or very high-risk individuals but must weigh the risks and benefits of extended lymph node dissection for each individual patient.
Presented by: Karim Touijer, MD, Department of Urology, Memorial Sloan Kettering Cancer Center, New York, New York
Written by: David B. Cahn, DO, MBS @dbcahn Fox Chase Cancer Center, Philadelphia, Pennsylvania at the 34th European Association of Urology (EAU 2019) #EAU19, conference in Barcelona, Spain from March 15-19, 2019.