The role of cytoreductive nephrectomy in metastatic renal cell carcinoma.

Abstract

e17080 Background: The role of cytoreductive nephrectomy (CN) in metastatic renal cell carcinoma (MRCC) is unclear. Two randomized clinical trials (RCT) in the cytokine era demonstrated a survival benefit of CN in MRCC. However, the efficacy of this approach is unknown after the introduction of tyrosine kinase inhibitor (TKI) therapy and immunotherapy (IC) in the frontline setting of MRCC. Methods: We studied the the impact of CN in MRCC on overall survival (OS) using the Surveillance, Epidemiology, and End Results (SEER)-18 registries. The R software was used for statistical analysis. Results: A total of 5488 patients with MRCC between 2010-2016 were identified. The median age was 62 years, 70% were males and 55% underwent partial or total nephrectomy. After a median follow-up time of 36 months, median OS was 12 months. Histology was clear cell (CC) in 79% the cases and 21% were non-clear cell (NCC). On univariate Cox regression, patients with CC histology who underwent CN had a 0.35 [95% confidence interval (CI), 0.33-0.38] lower risk of death compared to those who did not. After adjustment for age, gender, number of sites involved by metastasis (bone, liver, lung and/or brain), grade and administration of chemotherapy, patients who got CN had a 0.33 (CI, 0.29-0.36) lower risk of death compared to those who did not. The following factors were associated with higher risk of death in multivariable Cox proportional hazard ratio (HR) model: number of metastatic sites, HR = 1.50 (CI, 1.43-1.58); grade III vs. II, HR = 1.39 (CI, 1.22-1.59); grade IV vs. II, HR = 2.08 (CI, 1.80-2.39); female gender, HR = 1.16 (CI, 1.07-1.26), those who didn’t receive chemotherapy (or unknown status) with a HR of 1.39 (CI, 1.28-1.50) and increasing age with a hazard ratio of 1.009 (CI 1.005-1.013) for each year increase. With NCC, the following factors were associated with higher mortality: number of metastatic sites, HR = 1.34(CI, 1.24-1.46), older age, HR = 1.01(CI, 1.003-1.014) for each year increase, grade III vs. II,HR = 1.97(CI,1.41-2.77);IV vs. II,HR = 1.98 (CI, 1.41-2.77); and those who didn’t receive chemotherapy with HR = 1.52 (CI, 1.32-1.74). On the other hand, those who had CN had lower mortality, HR = 0.46 (CI, 0.38-0.55). Conclusions: In this large cohort, there was a survival benefit of CN in MRCC. However, our study is limited by the lack of treatment details and possible selection bias for the patients who got CN. TARIBO is an ongoing RCT that aims to identify the benefit from CN in MRCC in the TKI and IC era. Until the trial is concluded, CN should be considered for eligible patients with MRCC, regardless of histology.