Overall survival in patients with metastatic renal cell carcinoma and clinical N1 disease undergoing cytoreductive nephrectomy and lymph node dissection.

ABSTRACT

BACKGROUND: Patients with metastatic renal cell carcinoma (mRCC) have limited treatment options. Cytoreductive nephrectomy (CN) in select patients has been associated with improved survival. We aim to assess the survival in patients with mRCC and cN1 disease who underwent CN with and without lymph node dissection (LND). METHODS: Data were abstracted from the National Cancer Database for patients diagnosed with mRCC and cN1 from 2003 to 2014. Using propensity matching, we compared overall survival (OS) in patients who underwent a LND. Kaplan-Meier survival analysis and multivariable Cox proportional hazards modeling were used. We performed a logistic regression to assess predictors of LND. RESULTS: We identified 1,780 patients in the matched cohort, of which 71% underwent a LND. Patients undergoing LND were younger (P = 0.01) and had similar size tumors (5cm; P = 0.31). Increased LN yield was associated with LND at an academic center (odds ratio = 1.91; 95% CI 1.51-2.42; P<0.01). LND was associated with worse OS on KM analysis (log rank; P = 0.01). However, on multivariable analysis, we found no significant difference in OS (hazard ratio = 1.10; 95% CI 0.94-1.29; P = 0.22). However, when adjusting for number of positive LN removed, an increase in LN yield was associated with improved OS (hazard ratio = 0.97; 95% CI 0.95-0.99; P = 0.01). CONCLUSION: We demonstrate that patients with mRCC and cN1 disease undergoing LND did not have a survival benefit when compared with patients undergoing CN. However, lymph node yield showed an increase in survival when adjusting for the number of positive lymph nodes. Further research and validation of the ideal number of LN removed that may benefit patients is warranted.