Radical Nephrectomy With or Without Lymph Node Dissection for Nonmetastatic Renal Cell Carcinoma: A Propensity Score-based Analysis

Background: It is uncertain whether lymph node dissection (LND) provides a therapeutic benefit in renal cell carcinoma (RCC). Objective: To evaluate the association of LND with oncologic outcomes among patients undergoing radical nephrectomy (RN) for nonmetastatic RCC. Design, setting, and participants: A retrospective cohort study of 1797 patients treated with RN for M0 RCC between 1990 and 2010, including 606 (34%) who underwent LND. Intervention: RN with or without LND. Outcome measurements and statistical analysis: The associations of LND with the development of distant metastases, cancer-specific mortality (CSM), and all-cause mortality (ACM) were evaluated using 1: 1 propensity score (PS) matching, adjustment for/stratification by PS quintile, and inverse probability weighting. Cox models were used to evaluate the association of the number of lymph nodes removed with oncologic outcomes. Results and limitations: A total of 111 (6.2%) patients were pN1. The median follow-up after surgery was 10.6 yr. Following PS adjustment, there were no significant differences in clinicopathologic features between patients with and without LND. In the overall cohort, LND was not significantly associated with a reduced risk of distant metastases, CSM, or ACM. Moreover, LND was not associated with improved oncologic outcomes even among patients at increased risk of pN1 disease, including those with preoperative radiographic lymphadenopathy, or across increasing threshold probabilities for pN1 disease from 0.05 to 0.50. Among patients who underwent LND, the extent of LND was not significantly associated with the development of distant metastases, CSM, or ACM. Limitations include the retrospective design. Conclusions: We did not identify an oncologic benefit to LND in the overall cohort or among patients at increased risk of nodal disease. These findings do not support a therapeutic benefit to LND in patients with M0 RCC. Patient summary: Lymph node dissection does not appear to provide a therapeutic benefit in patients with nonmetastatic renal cell carcinoma. (C) 2016 European Association of Urology. Published by Elsevier B. V. All rights reserved.