Which biological pathways are responsible for the late appearance of brain metastases in renal cell carcinoma? Analysis of eight cases

BACKGROUND: Renal cell carcinoma (RCC) represents 1% of all cancers and its brain metastases amount to 8.1% of all metastatic tumors. Late brain metastases are defined as tumors that appear 10 years after diagnosis of the primary lesion. The objective of this work is to discuss which biological pathways are responsible for the late appearance of these metastases analyzing eight cases. CASE DESCRIPTION: We report here eight cases of late brain metastases of RCC treated between 2018 and 2021. Patients consulted for different clinical complaints. Brain magnetic resonance imaging and computed tomography scan were performed on all patients. They were treated by complete surgical resection plus radiosurgery or by radiosurgery alone. The histology of most metastases showed clear cell RCC. CONCLUSION: In the presence of a patient with an intracranial tumor and a history of RCC with more than 10 years of evolution, the presence of late metastasis should always be considered. There are many theories described in the literature that try to explain the late appearance of brain metastases from RCC (low mitotic index, impaired immune system, cross talk, self-seeding, and among others).