Early Identification of Asymptomatic Brain Metastases from Renal Cell Carcinoma

Current guidelines for metastatic renal cell carcinoma (mRCC) do not recommend routine brain imaging as part of the surveillance protocol unless central nervous system (CNS) symptoms or abnormal laboratory values suggest brain involvement. We hypothesized that strict adherence to these guidelines will delay diagnosis and management of RCC brain metastases. Retrospective review of our IRB-approved kidney cancer database examined a consecutive series of subjects from 1995 to 2012. We identified all mRCC patients with radiographic evidence of renal cell brain metastasis (RCCBM). RCCBM patients were divided into two cohorts: CNS symptoms present at RCCBM diagnosis and those without symptoms present at diagnosis. Fifty-two patients within our database met criteria; CNS symptoms were present at RCCBM diagnosis in 73 % (36) of patients. Median size of RCCBM on presentation was smaller in the asymptomatic verses the symptomatic cohort (0.83 vs. 1.7 cm, p = 0.003). Multivariate analysis demonstrated presence of CNS symptoms and female gender as a survival advantage (p < 0.05) while poor performance status, history of tobacco abuse and coexistence of lung metastasis were poor indicators for survival (p < 0.05). Patients with pulmonary metastases and a history of tobacco abuse are more likely to harbor RCCBM and perhaps in the absence of CNS symptoms these subjects should have routine brain surveillance incorporated into the RCC follow up. Overall, the current urologic guidelines may be missing a subset of metastatic RCC patients who could potentially benefit from early radiation or neurosurgical intervention. This may result in improved overall survival.