ASCO 2017: Extended versus limited pelvic lymphadenectomy during radical prostatectomy for intermediate- and high-risk prostate cancer: Early outcomes from a randomized controlled phase III study

Chicago, IL ( One of the age old questions for the surgical management of localized prostate cancer is the necessity and importance of pelvic lymphadenectomy. Specifically, which patients should receive a lymphadenectomy, how extended should the dissection be, and does lymphadenectomy improve survival endpoints or merely improve staging? At the ASCO 2017 prostate cancer poster session, Dr. Jean Felipe Prodocimo Lestingi presented their early outcomes from a phase III trial assessing extended versus limited pelvic lymphadenectomy for patients with intermediate- and high-risk prostate cancer. As the authors mention, the role of extended pelvic lymph node dissection (ePLND) in treating prostate cancer patients remains controversial.

For this study, patients with D'Amico intermediate or high risk prostate cancer, absence of bone metastasis, and no previous treatment were randomized to undergo extended or limited PLND (1:1) during radical prostatectomy. Limited PLND (lPLND) included the obturator chain bilaterally, and ePLND involved bilaterally chains including obturator, external-, internal-, common-iliac and pre-sacral nodes. The primary endpoint was biochemical recurrence-free survival (BRFS), analyzed in the intention-to-treat population.

From May 2012 to August 2016, 291 patients were randomized as outlined (n=145 – ePLND; n=146 – lPLND), with comparable baseline characteristics between the two groups. The sample size calculated was 260 patients and the trial was designed with 80% power and an alpha error rate of 0.05 to detect a 10% difference in 5-year biochemical recurrence-free survival rate in favor of the ePLND group (HR 0.78 vs 0.67). Over a median follow-up of 35.2 months, ePLND significantly increased operative time, estimated blood loss, length of hospital stay, and postoperative complications. There were 59% and 62% rates of stage ≥ pT3a disease for ePLND and lPLND groups, respectively. ePLND and lPLND yielded median (mean) 17 (19.8) and 3 (4.1) nodes, respectively (p < 0.001). ePLND resulted in 6.3 times more lymph node metastases (p < 0.001), however there was no difference in biochemical recurrence (PSA ≥ 0.2 ng/mL; p=0.4), receipt of radiotherapy, ADT, bone metastases or death. The strength of this study is the investigator’s ability to perform this surgical RCT.

The authors concluded that ePLND in intermediate- and high-risk prostate cancer patients is associated with better staging, increased morbidity and no oncological benefit with initial short follow-up. Whether longer follow-up results in significantly improved downstream endpoints is doubtful, but remains to be seen.
Clinical trial: NCT01812902

Presented By: Jean Felipe Prodocimo Lestingi, Sao Paulo State Cancer Institute – University of Sao Paulo, Sao Paulo, Brazil

Co-Authors: Giuliano Guglielmetti, Jose Pontes Jr, Anuar Ibrahim Mitre, Alvaro Sarkis, Diogo Assed Bastos, Rachel Riechelmann, Romulo Loss Mattedi, Mauricio Cordeiro, Rafael Coelho, Miguel Srougi, William Carlos Nahas
Written By: Zachary Klaassen, MD, Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre
Twitter: @zklaassen_md

at the 2017 ASCO Annual Meeting - June 2 - 6, 2017 – Chicago, Illinois, USA