Cytoreductive nephrectomy (CN) in patients with synchronous metastases from renal cell carcinoma: Results from the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC).

396 Background: The role of cytoreductive nephrectomy is unclear in patients with synchronous metastases from renal cell carcinoma (RCC) in the age of targeted therapy. Methods: Comparisons were made between patients treated with targeted therapy who had a CN versus not and adjusted using proportional hazards regression for known poor prognostic criteria (IMDC criteria Heng et al JCO 2009). Results: 2569/3245 (79%) mRCC patients received a nephrectomy. Patients who had nephrectomy before the diagnosis of metastatic disease were excluded (n=1634). Among the remaining patients, 935 patients had a CN and 676 patients did not have nephrectomy. All patients received targeted therapy with the majority receiving first-line sunitinib 72%, sorafenib 15%, temsirolimus 5%, bevacizumab 3%, pazopanib 3%. Patients who had CN had better IMDC prognostic profiles versus those without (favorable/intermediate/poor in 9%/63%/28% vs 1%/45%/54% p<0.0001). The median overall survival of patients with CN vs without was 20.6 vs 9.5 months (p<0.0001). When adjusted for IMDC criteria to correct for imbalances, the HR of death was 0.60 (95%CI 0.52-0.69, p<0.0001). The Table demonstrates the increasing benefit of CN if a given patient has a longer survival time. Conclusions: CN can be beneficial in patients with synchronous metastatic RCC even after adjustment for prognostic factors. Patients who are estimated to survive less than 9-12 months may have a marginal benefit compared to those with longer estimated survival. This may aid in patient selection as we await results from randomized controlled trials. [Table: see text]