Touijer and colleagues present extended follow-up results from a large randomised trial comparing limited pelvic lymph node dissection (l-PLND) and extended PLND (e-PLND) in prostate cancer patients undergoing radical prostatectomy. The study aimed to assess whether e-PLND, which includes external iliac, obturator, and hypogastric nodes, results in better oncological outcomes than l-PLND, which covers a smaller nodal area. At a median follow-up of 3.1 years, initial findings revealed no significant difference in biochemical recurrence (BCR) rates between the two groups, with similar lymph node yields (12 for l-PLND vs. 14 for e-PLND) and positive node rates (12% vs. 14%). However, after extended follow-up at 5.4 years, e-PLND showed a lower incidence of metastatic disease, with a 3% improvement in distant metastasis-free survival (dMFS) at 10 years (88% vs. 85%). The authors concluded that e-PLND should be the new standard of care. Despite these promising results, several methodological issues raise concerns about the study’s conclusions. First, the primary outcome was not clearly defined, and the endpoints were not pre-specified, which makes the findings appear more like a post hoc analysis than a well-designed trial. Moreover, imaging modalities used to detect metastases – such as PSMA, choline, or FDG PET scans – were not standardised or centrally reviewed, potentially compromising the reliability of the results. Six patients were excluded after preoperative bone metastases were identified, which highlights potential issues with imaging quality. Additionally, postoperative management varied widely between the groups, which may have influenced outcomes. For instance, adjuvant therapy was infrequently used (0.6%), and salvage treatments differed between the groups, with the l-PLND group receiving more androgen deprivation therapy (ADT) and the e-PLND group more radiotherapy (RT) ± ADT, making it difficult to isolate the effects of PLND alone. The study also showed that e-PLND’s benefits were most evident in the pN1 (node-positive) subgroup, where rapid metastatic progression occurred. However, it is unlikely that PLND extent alone accounts for such differences, suggesting postoperative therapies may play a more significant role. The unexpectedly high lymph node yield in the l-PLND group raises further concerns about surgical consistency. In conclusion, while the study provides useful insights, its methodological flaws and biases limit its potential to change clinical practice. Standardised imaging and consistent postoperative care are needed, and further research, particularly with PSMA PET staging, is essential.
Oncological benefits of extended pelvic lymph node dissection
Reviewed by Asif H Ansari
Oncological benefits of extended pelvic lymph node dissection: more fog or clarity to the debate?
