Brain metastases from renal cell carcinoma
see also Clear cell renal carcinoma brain metastases.
Brain metastases from renal cell carcinoma refer to the spread of cancerous cells from the kidneys to the brain. Renal cell carcinoma (RCC) is known for its tendency to metastasize to various organs, including the brain. When RCC metastasizes to the brain, it can form tumors or lesions within the brain tissue, which can lead to symptoms such as headaches, neurological deficits, seizures, and other manifestations depending on the location and size of the metastases.
Renal cell carcinoma is the most common kidney cancer which tends to metastasize to the brain in about 4–11% of cases with an average interval from nephrectomy to brain metastasis of 1–5 years 1) 2))
The metastatic tumor from RCC has the propensity of intratumoral hemorrhage and relatively massive surrounding edema compared with other metastatic tumors. These characteristics make an emphasis on the surgical resection in the management of metastatic tumor. However, the surgery is not always possible due to the characteristics of tumor and patient. The outcome of conventional whole brain radiotherapy is unsatisfactory due to the resistant feature of RCC to the radiation, although it plays an important role in other malignancies. The stereotactic radiosurgery (SRS) including various modalities have showed the excellent outcomes in the control of tumor itself and surrounding edema. The repeatability of SRS is also attractive merit, because the new brain metastasis can be encountered in anytime regardless of the first-line treatment modalities. A few adverse effects following SRS have been reported however, incidence and severity could be acceptable without severe morbidity. Therefore, SRS must be emphasized in the management of brain metastasis from RCC and individual various combined treatment strategies could be suggested 3).
Treatment
Prognosis
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.
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 inhibitors 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.
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 4).