Differences in Survival of Clear Cell Metastatic Renal Cell Carcinoma According to Partial vs. Radical Cytoreductive Nephrectomy

Background: It is unknown whether previously reported other-cause mortality (OCM) advantage of partial cytoreductive nephrectomy (PCN) vs. radical cytoreductive nephrectomy (RCN) still applies to contemporary clear cell metastatic renal cell carcinoma (ccmRCC) patients. Materials and Methods: We relied on the Surveillance, Epidemiology and End Results (SEER) database (2004-2019) to identify ccmRCC patients treated with PCN and RCN. Temporal trends of PCN rates within the SEER database were tabulated. After propensity score matching (PSM), cumulative incidence plots depicted 5-year OCM and cancer-specific mortality (CSM) of PCN and RCN patients. Multivariable Cox regression models tested for differences between PCN vs. RCN. Results: Of 5149 study patients, 237 (5%) underwent PCN vs. 4912 (95%) RCN. In the SEER database 2004 to 2019, rates of PCN in ccmRCC patients increased from 3.0% to 8.0% (estimated annual percent change [EAPC]: 3.0%; P = .04). After PSM, 5-year OCM rates were 2.4 vs. 7.5% for respectively PCN vs. RCN patients (P = .036). 5-year CSM rates were 50.8 vs. 53.6% for respectively PCN and RCN patients (P = .57). In multivariable Cox regression models, PCN was associated with lower OCM (Hazard Ratio (HR): 0.39; 95% confidence interval (CI): 0.18-0.84; P = .02) but did not affect CSM rates (HR: 0.99; 95% CI: 0.76-1.29; P = .96). Conclusions: We confirm the existence of OCM advantage after PCN vs. RCN in contemporary ccmRCC patients.