Nodal Disease In The Setting Of Metastatic Renal Cell Carcionoma: Can A Lymph Node Dissection Alter Outcomes?

386 Background: The impact of lymph node dissection (LND) in patients with metastatic renal cell carcinoma (mRCC) undergoing cytoreductive nephrectomy (CN) is unclear. The aims of this study were to determine the predictive ability of LN status for overall survival (OS) in patients treated with CN in the targeted therapy era and if LND increases the morbidity of CN. METHODS We performed a retrospective review of all patients with mRCC treated with CN at a single institution between 2004-2010. Patients participating in open or unpublished trials were excluded, leaving 173 patients for analysis. LNs >1cm by long axis diameter were considered clinically positive (cN+). OS was calculated using COX proportional hazard regression. Complications were classified using the modified Clavien system. RESULTS Sixty-five (37.6%) patients were clinically node positive (cN+). Median OS was significantly worse for the cN+ patients compared to cN0 patients [17.5 vs 29.1 mos;HR 1.8;(1.3-2.6)]. Clinical node status remained an independent predictor of OS on multivarible analysis (MV) [HR 1.7;CI 1.1-2.7]. LND was performed in 61/65 (93.4%) cN+ patients and in 56/108 (52%) of cN0 patients. Pathologic node positive disease (pN+) was more common in cN+ compared to cN0 patients (75% vs. 23%,p <0.001). pN+ patients had worse median OS than pN0 patients [16.0 v 35.5 mos;HR 2.3(1.5-3.6)]. Among pN+ patients (n=54), complete resection of all identifiable nodal disease was associated with an improved OS compared to patients with unresectable nodal disease (n=4) [16.0 v 5.6 mos;HR 2.9(1.0-8.3)]. On univariate analysis LND patients were more likely to have a post-operative complication (64% vs 43%,p=0.008) and more specifically chylous ascites (12 v 0,p=0.01). Despite this association, LND did not reach statistical significance when MV analysis was performed [OR 1.9;(0.9-3.8)]. CONCLUSIONS Among patients undergoing CN, those with cN+ disease had worse OS. Likewise, pN+ patients have worse OS than pN0 patients. LND is associated with higher morbidity than CN alone. Further efforts are needed to determine removal of pathologic nodes alters the natural history of the disease, and if the benefit offsets the increased morbidity.