Extended Pelvic Lymph Node Dissection Including Internal Iliac Packet Should Be Performed During Robot-Assisted Laparoscopic Radical Prostatectomy for High-Risk Prostate Cancer

Abstract

The indication and anatomic limits of pelvic lymph node dissection (PLND) have not been clearly defined. Therefore, we assessed whether the extent of PLND at robot-assisted laparoscopic radical prostatectomy (RALP) had any benefit on lymph node yield, staging accuracy, and biochemical recurrence (BCR) in patients with high-risk prostate cancer. Between July 2005 and July 2010, a retrospective analysis was performed on 200 patients with high-risk prostate cancer stratified by D'Amico classification. The study population was divided into different groups: patients in Group 1 had standard PLND, and Group 2 had extended PLND (ePLND). The clinicopathologic findings of patients and surgical outcomes of PLND with each procedure were measured. Kaplan-Meier and log rank tests were used to estimate BCR-free survival rates. Univariate and multivariate survival analyses were done with the Cox proportional hazard regression model. Medians of 15 (interquartile range, 11-19) and 24 (interquartile range, 18-28) lymph nodes were dissected in Groups 1 and 2, respectively (P<.001). The incidences of lymph node metastasis were 5.2% (8/155) in Group 1 and 22.2% (10/45) in Group 2. Regardless of the extent of PLND, the patients with positive lymph nodes had a significantly lower BCR-free survival than those with negative lymph nodes. Twenty-five percent (7/27) of positive lymph nodes were in the internal iliac packet and common iliac packet. In particular, of the positive internal iliac nodes, 75% (3/4) of nodes were found in that location, exclusively. An ePLND that identifies patients with lymph node metastasis including the internal iliac packet during RALP provides an accurate pathologic staging and may have survival benefits in high-risk prostate cancer.