The value of cytoreductive nephrectomy on the survival of metastatic renal carcinoma patients based on the number of site-specific metastases

BACKGROUND: There has been significant uncertainty in the selection of candidates for cytoreductive nephrectomy (CN) in patients with metastatic renal cell carcinoma (mRCC). This report investigates the influence of site-specific metastases (bone, brain, liver, and lung) on the survival benefit of CN. METHODS: Within the Surveillance, Epidemiology and End Results database (2010–2014), 1113 mRCC patients treated with CN (n = 618) or no surgery (NS, n = 495) met the selection criteria. 168 pairs of patients using propensity scores were matched to balance the selection bias of undergoing CN. Multivariable competing risks regression analysis was used to calculate cancer-specific mortality (CSM) and overall survival (OS). Cases were subdivided to investigate the advantages of each procedure. RESULTS: Before or after matching, CN led to better OS and lower CSM in Kaplan-Meier analysis. In matched cohort, decreased CSM after CN compared to without CN were consistently found in most subgroups stratified by age, T stage, and patients with ≤2 site-specific metastases. However, patients with ≥ 3 site-specific metastases, or patients with ≥cT3 stage combined with ≥ 2 site-specific metastases were not benefit from the cytoreductive nephrectomy. CONCLUSIONS: The potential benefit of CN disappeared in patients with ≥ 3 site-specific metastases, or patients with ≥cT3 combined with ≥ 2 site-specific metastases.