BERKELEY, CA (UroToday.com) - The role of radical prostatectomy in patients with high-risk prostate cancer remains controversial due to the probability of positive pelvic lymph nodes and decreased long-term survival. Pelvic lymph node dissection (PLND) in high-risk prostate cancer provides significant information regarding pathologic stage and regional recurrence rate.[1] Literature has indicated that a more extensive node dissection increases the retrieval of positive nodes that would be missed by a limited dissection and reduces biochemical failure due to removal of micro-metastases.[2] Oncological outcomes of robot-assisted laparoscopic radical prostatectomy (RALP) have been shown to be comparable to those of open series, even in high-risk prostate cancers.[3] Recent reports have demonstrated that PLND during RALP provided a high lymph node yield and appeared to have minimal morbidity compared with the open technique.[3, 4] In this study, we aim to assess whether the extent of PLND at RALP had any benefit on lymph node yield, staging accuracy, and biochemical recurrence (BCR) in patients with high-risk prostate cancers.
Between July 2005 and July 2010, 829 consecutive men underwent transperitoneal RALP with PLND by a single surgeon. Two hundred patients met our inclusion criteria, and they were divided into 2 groups: Group 1 had standard PLND, and Group 2 had extended PLND (ePLND). The clinicopathologic findings of patients and surgical outcomes were analysed. The template of sPLND, described by Walsh, consisted of obturator and external iliac nodal packets.[5] Thurairaja described the template of ePLND encompassing additional tissue on the medial and lateral aspect of the internal iliac vessels as well as along common iliac vessels up to the ureteric crossing.[6] We initiated our ePLND by carefully incising the peritoneum over the perceived area of the common iliac bifurcation, guided by the ureters. The dissection proceeded distally on the proximal common iliac artery to the common iliac bifurcation. Nodal tissue around the bifurcation was harvested. Next, lymphadenectomy was performed along the medial aspect of the ureter along the internal iliac artery to the level of the obligated umbilical artery. The lymphatic tissues around internal iliac vessels were labelled as the internal iliac specimens. Lymph node dissection continued along the external iliac artery from its origin down to the circumflex iliac vessels. The node of Cloquet marked the distal extent of dissection, and surrounding tissues were removed for pathological examination. All lympho-fatty tissues surrounding the obturator fossa along the obturator muscle were also removed, preserving the obturator nerve and vessels. Finally, preprostatic fat was removed and the endopelvic fascia identified. In total, 11 packets per patient were labeled as common iliac, internal iliac, external iliac, obturator, inguinal node (node of Cloquet), and preprostatic fat pad.
Although the majority of pre-operative parameters were similar between the 2 groups, pre-operative PSA, Gleason score on needle biopsy, and surgical specimen in Group 2 were significantly higher than those of Group 1. There were no differences in estimated blood loss, length of hospitalisation, and complication rates between the 2 groups. 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. Thirty-four patients (22.1%) in Group 1 and 16 (35.6%) in Group 2 had BCR. 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 4 patients with positive internal iliac nodes, the internal iliac package was the only site with positive lymph nodes in 3 (75%) of these patients. The usual limitations of a nonrandomized and retrospective design apply to our study. In addition, our short follow-up period may have contributed to the lack of an association between the extent of PLND and cancer-specific survival and overall survival rates. In conclusion, ePLND, which provides a higher lymph node yield, identifies a greater proportion of lymph node metastasis in patients with high-risk prostate cancer undergoing RALP. PLND-related complications were not significantly different between sPLND and ePLND. ePLND, which identifies patients with lymph node metastasis, especially in the internal iliac packet during RALP, provides more accurate pathologic staging and may have survival benefits in high-risk prostate cancer. We recommend a prospective randomized trial with longer term follow-up to verify the impact of ePLND on the outcomes of high-risk prostate cancers.
References:
- Heidenreich A, Ohlmann CH, Polyakov S. Anatomical extent of pelvic lymphadenectomy in patients undergoing radical prostatectomy. Eur Urol 2007;52:29–37.
- Joslyn SA, Konety BR. Impact of extent of lymphadenectomy on survival after radical prostatectomy for prostate cancer. Urology 2006;68:121–125.
- Yee DS, Katz DJ, Godoy G, et al. Extended pelvic lymph node dissection in robotic-assisted radical prostatectomy: Surgical technique and initial experience. Urology 2010;75:1199–1204.
- Truesdale MD, Lee DJ, Cheetham PJ, Hruby GW, Turk AT, Badani KK. Assessment of lymph node yield after pelvic lymph node dissection in men with prostate cancer: A comparison between robot-assisted radical prostatectomy and open radical prostatectomy in the modern era. J Endourol 2010;24:1055–1060.
- Walsh PC, Partin AW. "Anatomic radical retropubic prostatectomy." In: Wein AJ, Kavoussi LR, Novick AC, Partin AW, and Peters CA (eds): Campbell-Walsh Urology. Philadelphia: Saunders, 2007, pp. 2956–2978.
- Thurairaja R, Studer UE, Burkhard FC. Indications, extent, and benefits of pelvic lymph node dissection for patients with bladder and prostate cancer. Oncologist 2009;14:40–51.
Written by:
Koon Ho Rha, MD, PhD* and Sey Kiat Lim as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.
*Department of Urology
Urological Science Institute
Yonsei University Health System
134 Sinchon-dong
Seodaemun-gu, Seoul, 120-752
Republic of Korea
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