Outcomes Following Complete Surgical Metastasectomy for Patients with Metastatic Renal Cell Carcinoma: A Systematic Review and Meta-Analysis

Harras B. Zaid, William P. Parker, Nida S. Safdar, Boris Gershman, Patricia J. Erwin, M. Hassan Murad, Stephen A. Boorjian, Brian A. Costello, R. Houston Thompson, Bradley C. Leibovich

The benefit of complete surgical metastasectomy (CM) for patients with metastatic renal cell carcinoma (mRCC) remains controversial due to limited outcome data. Here, we performed a systematic review and meta-analysis to determine whether CM confers a survival benefit compared to incomplete or no metastasectomy (no-CM) for patients with mRCC. Ovid Embase, Medline, and Cochrane as well as Scopus databases were searched for studies evaluating CM in mRCC through 1/19/2016. Only comparative studies reporting adjusted hazard ratios (aHRs) for all-cause mortality of no-CM versus CM were included. Generic inverse variance with random effects models were used to determine the pooled aHR. Risk of bias was assessed with the Newcastle-Ottawa Scale. Eight published cohort studies at low or moderate potential for bias were included in the final analysis. The studies reported on a total of 2267 patients (958 undergoing CM, and 1309 no-CM). Median overall survival ranged between 36.5-142 months for those undergoing CM, compared to 8.4-27 months for no-CM. CM was associated with a reduced risk of all-cause mortality compared with no-CM (pooled aHR 2.37; 95% CI 2.03-2.87; P<0.001), with low heterogeneity (I(2) = 0%). CM remained independently associated with reduction in mortality across a priori subgroup and sensitivity analyses, and whether or not performance status was adjusted for. CM for mRCC is associated with improved survival compared with no-CM based on meta-analysis of observational data. Consideration should be given to perform CM in patients with mRCC who are surgical candidates when technically feasible.