e543 Background: The optimal treatment for high-risk prostate cancer (Pca) remains to be established. We previously reported favorable biochemical recurrence-free survival (BRFS) in high-risk Pca patients treated with neoadjuvant therapy comprising a luteinizing-hormone-releasing hormone (LHRH) agonist plus low-dose estramustine phosphate (EMP) (LHRH+EMP) followed by radical prostatectomy (RP). The aim of this study was to assess whether neoadjuvant LHRH+EMP confers an oncological benefit for high-risk Pca compared to extended lymph node dissection (e-PLND). Methods: The Michinoku Urological Cancer Study Group database contained the data of 2403 consecutive Pca patients treated with RP at 4 institutes between March 2000 and December 2014. In the e-PLND group, we identified 238 high-risk Pca patients who underwent RP and e-PLND, with lymphatic tissue removal around the obturator and the external iliac regions, and hypogastric lymph node dissection. The neoadjuvant therapy with limited PLND (l-PLND) group included 280 high-risk Pca patients who underwent RP and removal of the obturator node chain between September 2005 and June 2014 at Hirosaki University. The neoadjuvant LHRH+EMP therapy included the administration of 280 mg/day of LHRH and EMP for 6 months before RP. The outcome measure was BRFS. Results: The 5-year BRFS rates for the neoadjuvant therapy with l-PLND group and e-PLND group were 84.9% and 54.7%, respectively ( P < 0.0001). The operative time was significantly longer in the e-PLND group compared to that of the neoadjuvant therapy with l-PLND group. Grade 3/4 surgery-related complications were not identified in both groups. Conclusions: Although the present study was not randomized, neoadjuvant LHRH+EMP therapy followed by RP might reduce the risk of biochemical recurrence.
