Extended Pelvic Lymph Node Dissection in Prostate Cancer: A Game-Changer in Metastasis Control
A groundbreaking randomized clinical trial has shed new light on the effectiveness of extended pelvic lymph node dissection (PLND) in controlling metastasis among prostate cancer patients undergoing radical prostatectomy. The study, which spanned over 5.5 years and involved nearly 1,500 patients, compared the outcomes of limited versus extended PLND, revealing significant benefits of the latter approach.
Key Findings and Clinical Implications
The trial demonstrated that extended PLND, which covers the external iliac, obturator, and hypogastric nodes, offers superior protection against metastasis compared to limited PLND. Specifically, the study found a statistically significant protective effect of extended PLND on metastasis, with hazard ratios (HR) indicating a reduced risk of any metastasis (HR 0.82; 95% CI 0.71, 0.93; p=0.003) and distant metastasis (HR 0.75; 95% CI 0.64, 0.88; p<0.001).
These findings underscore the clinical value of extended PLND, particularly for patients with intermediate and high-risk prostate cancer where the risk of lymph node involvement exceeds 2%. The results align with the National Comprehensive Cancer Network (NCCN) guidelines, reinforcing the recommendation for extended PLND in well-selected cases to prevent or delay metastatic spread.
Innovative Trial Design: A Clinically Integrated Approach
A notable aspect of this study is its innovative, clinically integrated trial design, which facilitated a large-scale randomized trial within routine clinical practice. This approach minimized the logistical challenges and costs typically associated with surgical trials, enabling the enrollment of nearly 1,500 patients from a single tertiary center in just over five years. By streamlining eligibility criteria and employing cluster randomization of surgeons to PLND templates every three months, the study achieved a level of efficiency uncommon in surgical oncology trials.
This patient-centered model not only enhances trial participation by reducing additional burdens on patients but also offers a sustainable blueprint for future large-scale investigations in urology and beyond.
Biological Mechanisms and Future Research
Post hoc analyses from the trial suggest that extended PLND may interrupt cancer's self-seeding process, a key driver of metastatic spread. The study also highlights the importance of anatomical location over node count in determining metastatic risk, pointing towards the need for a targeted approach in extended PLND.
Conclusion
The study provides compelling level-1 evidence supporting the oncologic benefits of extended PLND in reducing metastasis risk in prostate cancer patients undergoing radical prostatectomy. Its innovative trial design offers a promising model for future research, emphasizing the importance of refining selection criteria for extended PLND and exploring the biological pathways of metastatic spread.
Written by: Sunny Nalavenkata, MD, Andrew Vickers, PhD, & Karim A. Touijer, MD, MPH
Memorial Sloan Kettering Cancer Center, New York, NY
