Extended pelvic lymph node dissection including internal iliac packet should be performed during robot-assisted laparoscopic radical prostatectomy for high-risk prostate cancer

Introduction: 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. Patients and Methods: 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. Results: 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. Conclusions: 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.