Radical Nephrectomy with or without Lymph Node Dissection for High Risk Nonmetastatic Renal Cell Carcinoma: A Multi-Institutional Analysis.

PURPOSE: Lymph node dissection may benefit patients at increased risk for lymph node metastases from renal cell carcinoma. Therefore, we evaluated the association of lymph node dissection with survival in patients at high risk undergoing radical nephrectomy for renal cell carcinoma. MATERIALS AND METHODS: We identified 2,722 patients with M0 renal cell carcinoma who underwent radical nephrectomy with or without lymph node dissection at 2 international centers from 1990 to 2010. The associations of lymph node dissection with the development of distant metastases, and cancer specific and all cause mortality were evaluated using propensity score techniques and traditional multivariable Cox regression. Subset analyses were done to examine patients at increased risk of lymph node metastases. RESULTS: Overall 171 patients (6.3%) had pN1 disease. Median followup was 9.6 years. Clinicopathological features were well balanced after propensity score adjustment. Lymph node dissection was not significantly associated with a reduced risk of distant metastases, or cancer specific or all cause mortality in the overall cohort, among patients with preoperative radiographic lymphadenopathy (cN1), or across an increasing probability of pN1 disease from 0.10 or greater to 0.50 or greater. Neither extended lymph node dissection nor the extent of lymph node dissection was associated with improved oncologic outcomes. CONCLUSIONS: The current analysis of a large, international cohort indicates that lymph node dissection is not associated with improved oncologic outcomes among patients at high risk who undergo radical nephrectomy for M0 renal cell carcinoma. This includes patients with radiographic lymphadenopathy (cN1) and across increasing probability thresholds of pN1 disease.