Impact of metastasectomy on progression free and overall survival in metastatic renal cell carcinoma: Analysis of the REMARCC registry.

Abstract

753 Background: The role of metastasectomy has been in flux as treatment paradigms for management of metastatic renal cell carcinoma (mRCC) have shifted. We examined outcomes of surgical metastasectomy stratified in the setting of different mRCC risk groups. Methods: Multicenter retrospective analysis of patients from the REMARCC (REgistry of MetAstatic RCC) database. The cohort was subdivided by Motzer RCC criteria (low, intermediate, and high risk), and impact of metastasectomy was analyzed via multivariable analysis (MVA) and Kaplan Meier analyses (KMA). Primary outcome was progression free survival (PFS) and secondary outcome was overall survival (OS). Results: 438 patients (46 low risk, 262 intermediate risk, 140 high risk) with median follow-up 16 months were analyzed. Metastasectomy was performed in 18 (39%), 63 (24%), and 32 (23%) of low, intermediate and high risk groups (p=0.04). Risk groups differed significantly with respect to ECOG performance status (p<0.001), metastases at diagnosis (low 1.72, intermediate 3.49, high 6.45, p<0.001), hemoglobin (p<0.001) and LDH (p<0.001). MVA for PFS revealed age (OR=1.03, p=0.05), BMI (OR=1.05, p=0.01), and higher risk category [vs. low (referent) intermediate OR=7.4, p<0.001, high OR=3.4, p=0.01] to be independent risk factors. MVA for OS revealed age (OR=1.03, p=0.02), BMI (OR=1.06, p=0.01), and higher risk category [low (referent) vs. intermediate OR=2.8, p=0.03, high OR=2.3, p=0.01] to be independent risk factors. KMA for PFS demonstrated that metastasectomy was associated with longer PFS in intermediate (24.0 vs. 6.7 months, p=0.01) but not high risk (4.2 vs. 4.0 months, p=0.58) and low risk (p=0.51) groups. KMA for OS demonstrated that metastasectomy was associated with longer median OS in the intermediate (56.9 vs. 29.3 months, p=0.01) and high risk (18.2 vs. 10.5, p=0.01), but not low risk (p=0.21) groups. Conclusions: Receipt of metastasectomy was associated with improved PFS in intermediate risk and improved OS in intermediate and high risk mRCC patients. These findings challenge prevailing assumptions about utility of metastasectomy. Further investigation is requisite to refine criteria for employment.