Impact of Metastasectomy on Cancer Specific and Overall Survival in Metastatic Renal Cell Carcinoma: Analysis of the REMARCC Registry

BACKGROUND: Treatment paradigms for management of metastatic renal cell carcinoma (mRCC) are evolving. We examined impact of surgical metastasectomy on survival across in mRCC stratified by risk-group.

METHODS: Multicenter retrospective analysis from the Registry of Metastatic RCC database. The cohort was subdivided utilizing Motzer criteria (favorable-, intermediate-, high-risk). Primary outcome was all-cause mortality (ACM)/overall survival (OS); secondary outcome was cancer-specific mortality (CSM)/cancer-specific survival (CSS). Impact of metastasectomy was analyzed via Cox-Regression analysis adjusting for potential prognostic variables and Kaplan-Meier analysis (KMA) within each risk-group.

RESULTS: Four hundred thirty-one patients (59 favorable-risk, 274 intermediate-risk, 98 high-risk; median follow-up 27.2 months) were analyzed. Metastasectomy was performed in 22 (37%), 66 (24%), and 32 (16%) of favorable-, intermediate- and high-risk groups (P = .012). Median number of metastases at diagnosis differed significantly (favorable-risk 2, intermediate-risk 3.4, high-risk 5.1, P < .001). On Cox-regression, high-risk (HR = 1.72, P = .002) was associated with worsened ACM, while metastasectomy was associated with improved ACM (HR = 0.56, P = .005). On KMA, median OS (months) was longer with metastasectomy in favorable- (92.7 vs. 25.8, P = .003) and intermediate-risk (26.3 vs. 20.1, P = .038), but not high-risk (P = .911) groups. Metastasectomy was associated with longer CSS in favorable- (76.1 vs. 32.8, P = .004) but not intermediate- (P = .06) and high-risk (P = .595) groups.

CONCLUSIONS: Metastasectomy was independently associated with improved ACM and CSM, as well as improved CSS and OS in favorable- and intermediate-risk mRCC patients. Metastasectomy may be considered as component of multimodal management strategy in favorable and intermediate-risk subgroups. In high-risk patients, metastasectomy should be deferred except in select circumstances.