Survival of patients with clear cell renal carcinoma according to number and location of organ-specific metastatic sites

Background: The prognostic significance of number and location of organ-specific metastatic sites in treated metastatic clear cell renal carcinoma (ccmRCC) patients is object of debate. The current study aimed to test the association between number and location of organ -specific metastatic sites and overall survival (OS) in ccmRCC.Materials and methods: Within Surveillance, Epidemiology and End Results database (2010-2018), all ccmRCC patients treated with cytoreductive nephrectomy and/or systemic therapy were identified. Kaplan-Meier plots and Cox regression models focused on: A). number of organ-specific metastatic sites: solitary vs. 2 vs. 3 or more; B). solitary organ-specific metastatic sites (lung vs. bone vs. liver vs. brain); C). combinations of 2 and 3 or more different organ-specific metastatic sites.Results: Of 4,527 patients (median OS: 19 months), 3,054 (67%) harbored solitary organ-specific metastatic sites (27 months) vs. 1,153 (25%) combinations of 2 different organ-specific metastatic sites (12 months) vs. 320 (8%) combinations of 3 or more different organ - specific metastatic sites (7 months). In patients with solitary organ-specific metastatic sites, bone metastases portended the longest median OS (median OS: 31 months) vs. liver metastases portended the shortest median OS (16 months). Both were independent predictors of OS (multivariable hazard ratio, bone: 0.87; liver: 1.21). Median OS was similarly poor in patients with combinations of 2 different organ -spe-cific metastatic sites (9-13 months), regardless of their location. The same pattern applied to patients with combinations of 3 or more differ-ent organ-specific metastatic sites (6-7 months).Conclusions: Solitary organ-specific metastatic sites portend the most favorable OS (16-31 months). Solitary bone metastases yield the longest vs. liver metastases the shortest OS. Invariably poor OS applies to combinations of 2 (9-13 months), as well as 3 or more different organ-specific metastatic sites (6-7 months), regardless of their location. (c) 2023 Elsevier Inc. All rights reserved.