Outcomes and prognostic factors in metastatic renal cell carcinoma patients with brain metastases

Background: To evaluate the outcomes and prognostic factors in patients with brain metastatic renal cell carcinoma (bmRCC). Methods: The data of 322 patients with metastatic renal cell carcinoma, taken between 2012 and 2020, were retrospectively reviewed. Overall survival (OS) and prognostic factors were evaluated with Kaplan-Meier analysis and Cox regression analysis. Results: Forty (12.4%) of the patients had bmRCC. Seventeen (42.5%) of the patients were de novo metastatic, and nine (22.5%) of the patients had brain metastases at presentation. Twenty-four (60%) patients previously had received various therapies (tyrosine kinase inhibitor or checkpoint inhibitors). After brain metastases developed, 35 (87.5%) of the patients received brain radiotherapy (whole-brain radiotherapy or stereotactic radiosurgery), and twenty-five (62.5%) patients received different systemic therapies. Nine patients received sunitinib, nine received pazopanib, five received nivolumab, and two received axitinib. The median OS was 8.8 months (range: 2.9-14.6) for all patients with bmRCC. In univariate analysis, the number of brain metastasis (P = 0.35), the site of brain metastasis (left, right or bilateral) (P = 0.79), the largest size of brain metastasis (P = 0.45), the number of extracranial metastatic sites (P = 0.81), de novo metastatic disease (P = 0.17), primary tumor site (left or right) (P = 0.90), and tumor grade (P = 0.09) were not statistically significant factors on OS. However, age (P = 0.02), a history of nephrectomy (P < 0.001), receiving brain radiotherapy (P = 0.005), and type of systemic treatment (P = 0.04) were statistically significant. Only, the effect of brain radiotherapy on OS (P = 0.01) was confirmed in multivariate analysis. Conclusions: In this study, we observed that the prognosis of patients with bmRCC was poor. Despite a small number of patients, we detected that the effect of tyrosine kinase inhibitors and nivolumab was comparable, and receiving brain radiotherapy was a prognostic factor for OS.