Impact of early identification of brain metastases in metastatic renal cell carcinoma (mRCC).

620 Background: Up to one-third of patients with mRCC can present with asymptomatic brain metastases (BM). Timely identification of BM allows for the delivery of early local interventions, which may lead to improved patient outcomes. To investigate the potential utility of routine intra-cranial imaging, we compared the outcomes of mRCC patients with asymptomatic versus symptomatic BM. Methods: Using the Canadian Kidney Cancer information system (CKCis) database, we identified mRCC patients diagnosed with BM between 2011 and 2018. This cohort was divided into two groups dependent on the presence or absence of neurological symptoms. Baseline patient demographics, clinico-pathological disease characteristics and survival data were extracted. Statistical analysis was through chi-square tests, analysis of variance and Kaplan-Meier method to characterize survival outcomes. Results: 269 mRCC patients with BM were identified with the majority presenting with symptomatic disease (n=163; 61%). No significant differences in clinico-pathological disease characteristics were identified. Median overall survival (OS) from mRCC diagnosis for asymptomatic patients was 33.4 months (interquartile range, IQR 27.8-64.4) versus 34.5 months (20.4-43.4) for symptomatic patients (p=0.35). Median OS from time of BM diagnosis revealed a trend favoring asymptomatic, as compared to symptomatic, patients [24.5 (17.6-24.9) vs. 13.1 months (9.0-20.6), p=0.06]. Factors associated with worse OS from time of BM diagnosis included presentation with symptomatic BM [hazard ratio, HR (95% CI): 1.40 (1.03-1.90), p=0.034] and International Metastatic Renal Cell Carcinoma Consortium Database (IMDC)-characterized intermediate/poor risk disease [HR (95% CI): 1.47 (1.01-2.13), p=0.045]. Conclusions: Routine intra-cranial imaging may lead to earlier identification of BM in mRCC. However, further investigation as to whether this practice improves survival is warranted.