866P - Pelvic lymph node dissection and its extent on survival benefit in prostate cancer patients with a risk of lymph node invasion>5%: A propensity score matching analysis from SEER database

Abstract

BackgroundThe aim of the study was to evaluate the therapeutic role of pelvic lymph node dissection (PLND) and its extent in North American patients with a risk of lymph node invasion (LNI)>5%. MethodsData of 20,668 patients treated with radical prostatectomy (RP) with and without PLND from SEER database between 2010 and 2015 were retrospectively analyzed. All patients had a risk of LNI>5% according to 2012-Briganti nomogram. Propensity score matching (PSM) was performed to balance baseline characteristics between patients with and without PLND. Kaplan-Meier curves and Cox regression were used to evaluate the impacts of the PLND and its extent on cancer-specific survival (CSS) and overall survival (OS). ResultsThe median follow-up was 32 months. In overall cohort, patients with PLND were associated with more aggressive clinicopathologic characteristics and had poorer survival compared to those without PLND (5-year CSS rate: 98.4% vs. 99.7%, p<0.001; 5-year OS rate: 96.3% vs. 97.8%, p<0.001). PSM resulted in 4,267 patients in each group. In the post-PSM cohort, no significant difference in survival was found between patients with and without PLND (5-year CSS rate: 99.4% vs. 99.7%, p=0.479; 5-year OS rate: 97.3% vs. 97.8%, p=0.204). In addition, the extent of PLND had no impact on prognosis (all p<0.05). Subgroup analyses reported similar negative findings. ConclusionsNeither PLND nor its extent was associated with survival in North American patients with a risk of LNI>5%. Legal entity responsible for the studyHao Zeng. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.