Incidence, distribution, and outcomes of node positive patients at radical prostatectomy: Manitoba Prostate Center experience.

Abstract

162 Background: Pelvic lymph node dissection at the time of radical retropubic prostatectomy (RRP) varies among surgeons and institutions. Differences focus on candidacy for node dissection and the limit of dissection. Standard lymph node dissection is typically above the obturator nerve to external iliac vessels. We analyzed our local experience of lymph node metastases at time of surgery. Methods: Data from the Manitoba Prostate Center were collected on consective patients undergoing RRP from January 2003 to June 2013 by two urologists with subspecialty training in oncology. Information extracted includes age, prostate-specific antigen (PSA), biochemical recurrence characteristics, and biopsy and pathological results. Results: Four hundred twenty consecutive patients comprised the data set and of whom 411 underwent a RRP and nine aborted prostatectomies. Average age of patients was 60 with an average preoperative PSA of 11. Overall lymph node metastases rate is 16.1%. Of the N1 patients, average number of positive nodes was 2.3. Average nodes removed for all patients were 13.4. Positive nodes on the right were found 53% of the time and 47% on the left. Locations of nodes are as follows: right external iliac, obturator, and hypogastric, 12%, 6%, and 19%, respectively; and for left external iliac, obturator, and hypogastric 9%, 3%, and 16%, respectively of all total nodes. One node was identified as other, and one surgeon sent packets as right pelvic and left pelvic with positive nodes 16% and 19% of all total positive nodes respectively. When looking at zones of a pelvic lymph node dissection separately, 54% are hypogastric, 13% obturator, and 33 external iliac. With an average of 37 months follow-up two patients with N1 disease died and only one from prostate cancer. Seventy nine percent had biochemical recurrence. Median time to treatment for biochemical recurrence was 4.5 months (0 to 33 months) with a median PSA of 0.28. Conclusions: This contemporary series of pelvic lymph node dissection with RRP represents high lymph node metastases (16%) relative to literature. Performing a limited pelvic lymph node dissection would under stage 54% of our patients. Despite high biochemical recurrence only one patient died of prostate cancer.