Extended pelvic lymphadenectomy in men undergoing radical prostatectomy - an update on > 300 cases

Abstract

4612 Background: Lymph node dissection (LND) in PCA is considered as a mere staging procedure and limited to obturator and external iliac nodes. Since the prostate drains into the external iliac, hypogastric, lateral and subaortic sacral nodes, metastases might be missed by the standard approach. We performed a radical pelvic lymphadectomy (RLND) in pts with PCA to assess frequency and location of lymph node metastases and to evaluate the reliability of current prediction models for lymph node involvement. Methods: 311 pts underwent RLND at time of radical retropubic prostatectomy via an extraperitoneal approach. RLND comprised 8 selective fields: external, internal and common iliac nodes, obturator nodes bilaterally. Nodes from each location and side were submitted separately for pathohistologic evaluation. Pathohistology of lymph nodes was compared to serum PSA, preoperative clinical stage and biopsy Gleason sum, pathohistological stage and Gleason sum of the prostatectomy specimen. Reliability of Partin tables, CART analysis and clinical parameters in terms of accurate prediction of lymph nodes metastases was evaluated. Results: Lymph node metastases were diagnosed in 19.8%; mean number of dissected lymph nodes was 28 (21–42). 22% of lymph node metastases were located in the internal and common iliac region only. 23/58 pts had 1 positive lymph node, 18 pts had 2, 7 pts had 3 and 8 pts had > 3 lymph nodes involved. Preoperative PSA serum levels were 26.8 (3.5–133)ng/ml and 16.5 (2.5–125)ng/ml in pts with and without lymph node metastases, resp. (p<0.05). CART nomograms did not accurately predict lymph node metastases with 58% of pN+ having been understaged. 27% and 58% of pN+ pts had serum PSA levels <10ng/ml and a biopsy Gleason sum <7, resp. The Partin tables understaged 33.5% of pts with positive lymph nodes. Conclusions: 47% of pts demonstrate positive lymph nodes around the internal and common iliac artery making this area essential for adequate staging LND. Current clinical staging systems (Partin, CART) miss up to 50% of all pN+ pts. Radical pelvic lymphadenectomy represents the standard lymphadenectomy technique of choice in surgical management of PCA. No significant financial relationships to disclose.