Limited versus Extended Pelvic Lymph Node Dissection for Prostate Cancer: A Randomized Clinical Trial

Abstract

Background: Pelvic lymph node dissection (PLND) is the most reliable procedure for lymph node staging. However, the therapeutic benefit remains unproven; although most radical prostatectomies at academic centers are accompanied by PLND, there is no consensus regarding the optimal anatomical extent of PLND.

Objective: To evaluate whether extended PLND results in a lower biochemical recurrence rate.

Design, setting, and participants: We conducted a single-center randomized trial. Patients, enrolled between October 2011 and March 2017, were scheduled to undergo radical prostatectomy and PLND. Patients were assigned to limited or extended PLND by cluster randomization. Specifically, surgeons were randomized to perform limited or extended PLND for 3-mo periods.

Intervention: Randomization to limited (external iliac nodes) or extended (external iliac, obturator fossa and hypogastric nodes) PLND.

Outcome measurements and statistical analysis: The primary endpoint was the rate of biochemical recurrence.

Results and limitations: Of 1440 patients included in the final analysis, 700 were randomized to limited PLND and 740 to extended PLND. The median number of nodes retrieved was 12 (interquartile range [IQR] 8-17) for limited PLND and 14 (IQR 10-20) extended PLND; the corresponding rate of positive nodes was 12% and 14% (difference -1.9%, 95% confidence interval [CI] -5.4% to 1.5%; p = 0.3). With median follow-up of 3.1 yr, there was no significant difference in the rate of biochemical recurrence between the groups (hazard ratio 1.04, 95% CI 0.93-1.15; p = 0.5). Rates for grade 2 and 3 complications were similar at 7.3% for limited versus 6.4% for extended PLND; there were no grade 4 or 5 complications.

Conclusions: Extended PLND did not improve freedom from biochemical recurrence over limited PLND for men with clinically localized prostate cancer. However, there were smaller than expected differences in nodal count and the rate of positive nodes between the two templates. A randomized trial comparing PLND to no node dissection is warranted.

Patient summary: In this clinical trial we did not find a difference in the rate of biochemical recurrence of prostate cancer between limited and extended dissection of lymph nodes in the pelvis. This study is registered on ClinicalTrials.gov as NCT01407263.

Keywords: Lymphatic metastasis; Pelvic lymph node dissection; Prognosis; Prostatic neoplasms.

Fig. 1 –

Pelvic lymph node template. Limited node dissection includes region 1 (external iliac nodes), and the extended dissection includes regions 1 (external iliac nodes), 2 (obturator fossa nodes), and 3 (hypogastric nodes).

Fig. 2 –

Recruitment, randomization, and patient flow. MSK = Memorial Sloan Kettering Cancer Center; PLND = pelvic lymph node dissection; RP = radical prostatectomy.

Fig. 3 –

Biochemical recurrence (BCR)-free survival after radical prostatectomy for limited (gray line) versus extended (black line) pelvic lymph node dissection (PLND).