A Retrospective Study of Metastatic Renal Cell Carcinoma Patients With Brain Metastases

Abstract Metastatic renal cell carcinoma (mRCC) involving the central nervous system is currently an excluded subgroup of patients in the systemic treatment; for this reason, there is no solid data to support the efficacy of therapies in this subgroup. That is why it is important to describe real-life experiences in order to know if there is a special change in clinical behavior or treatment response in these kinds of patients. Patients and methods A retrospective review was performed to characterize mRCC patients diagnosed with brain metastases (BrM) during treatment at the National Institute of Cancerology of Bogota, Colombia. Descriptive statistics and time-to-event methods are used to evaluate the cohort. For the descriptive measures of quantitative variables, the mean with standard deviation was taken, and the minimum and maximum values were reported. In the case of qualitative variables, absolute and relative frequencies were used. The software used was R - Project v4.1.2 (R Foundation for Statistical Computing, Vienna, Austria). Results A total of 16 patients were included with mRCC between January 2017 to August 2022 with a median 35.1-month follow-up, 4/16 (25%) were diagnosed with BrM at the time of screening and 12/16 (75%) during treatment. The International Metastatic RCC Database Consortium risk (IMDC) was favorable for 12.5%, intermediate for 43.7%, and poor for 25%, and not classified for 18.8%, BrM involvement was multifocal in 50% of the population and localized, brain-directed therapy was done in 43.7% of patients, predominantly palliative radiotherapy. Median overall survival (OS) for all the patients regardless of the time of metastatic presentation of the disease in the central nervous system was 53.5 months (0-70.3), and OS for cases with central nervous system involvement was 10.9 months. IMDC risk did not correlate with survival (log-rank, p=0.67). The OS for the subgroup of patients who debut with metastatic disease in the central nervous system is different from the group that developed metastasis in the progression of their disease (OS of 42 vs 3.6 months, respectively). Conclusions This is the largest descriptive study in Latin America and the second in the world from one institution that admits patients with metastasic renal cell carcinoma and central nervous system metastasis. In these kinds of patients with metastatic disease or progression to the central nervous system, there is a hypothesis that shows more aggressive clinical behavior. There is limited data on locoregional intervention to metastatic disease in the nervous system drastically, but trends show this could impact overall survival outcomes.