Efficacy of a neoadjuvant gonadotropin-releasing hormone antagonist plus low-dose estramustine phosphate in high-risk prostate cancer: A single-center study.

Abstract

e542 Background: The optimal treatment for high-risk prostate cancer (Pca) remains to be established. We previously reported favorable biochemical recurrence-free survival (BRFS) for high-risk Pca patients treated with neoadjuvant therapy comprising a luteinizing hormone-releasing hormone agonist plus low-dose estramustine (LHRH agonist + EMP) prior to radical prostatectomy (RP). In the present study, we evaluated the efficacy of neoadjuvant therapy comprising a gonadotropin-releasing hormone antagonist plus low-dose estramustine phosphate (GnRH antagonist + EMP) in patients with high-risk Pca. Methods: Between September 2005 and March 2016, we identified 406 high-risk Pca patients of whom 136 received neoadjuvant GnRH antagonist + EMP and 270 received LHRH agonist + EMP before RP. We retrospectively evaluated the clinical and pathological covariates between the two groups. The primary endpoint was the rate of pathological ≤ T2 status, and the secondary endpoint was BRFS. Results: The rates of pathological ≤ T2 status were 80.2% and 61.5% in the GnRH antagonist + EMP and LHRH agonist + EMP groups, respectively ( P < 0.001). The 3-year BRFS rates were 97.8% and 85.2% in the GnRH antagonist + EMP and LHRH agonist + EMP groups, respectively ( P = 0.021). Multivariate analysis revealed that biopsy Gleason score, GnRH antagonist + EMP, and clinical T stage were independent predictors of pathological ≤ T2 status in surgical specimens. Conclusions: Our findings suggest that neoadjuvant GnRH antagonist + EMP followed by RP may improve the pathological outcomes and reduce the risk of biochemical recurrence in patients with high-risk Pca. Further prospective studies to confirm these findings are warranted.