Survival benefit with extended lymphadenectomy for advanced renal malignancy: A population-based analysis

OBJECTIVE: We used population-based data to examine the possible benefit of extended lymphadenectomy for patients with renal malignancy in the setting of more advanced disease. METHODS: The Surveillance, Epidemiology, and End Results (SEER) database was utilized to identify non-metastatic, T3-T4 renal cancer patients from 2004–2015 treated with removal of ≥1 lymph node at the time of nephrectomy. Non-parametric bivariate statistics were used to assess associations between covariates of interest and extended lymphadenectomy (≥10 lymph nodes removed). Cancer-specific survival (CSS) and overall survival (OS) benefit was evaluated using Kaplan–Meier analysis. RESULTS: Of the 4397 patients identified, 816 (18.6%) underwent extended lymphadenectomy. For patients with T3a disease, 5-year CSS and OS benefit with extended lymphadenectomy did not reach statistical significance (CSS: hazard ratio [HR] 0.98, 95% confidence interval [CI] 0.77–1.24; OS: HR 0.96, 95% CI 0.77–1.20). Conversely, for those with T3b-T3c disease, extended lymphadenectomy led to statistically significant improvements in both 5-year CSS and OS compared to non-extended lymphadenectomy (CSS: HR 0.78, 95% CI 0.61–0.99; OS: HR 0.72, 95% CI 0.58–0.90). Finally, for those with T4 disease, use of extended lymphadenectomy had OS benefit after 5 years (OS: HR 0.51, HR 0.29–0.90, p = 0.02). CONCLUSION: Based on population-level data, extended lymphadenectomy was associated with improved survival in select patients with advanced renal malignancy treated with surgical nephrectomy. Understanding the basis of these real-world findings in the face of conflicting randomized trial results will be key, moving forward.