Breast Cancer And Renal Cell Cancer Metastases To The Brain

Metastatic tumors from systemic cancers comprise the majority of brain tumors. These tumors most commonly originate from the lung and breast skin or kidney cancers. There are numerous similarities regarding the pathophysiology of these entities. Primary tumors spread to the central nervous system in a stepwise and highly concerted fashion. Tumor particles must breach the containment organ and sub-sequently travel via the blood stream to lodge within the brain. Trans-endothelial migration allows cells to penetrate the blood brain barrier. Tumor emboli must then survive and grow within the brain microenvironment with local nutrient supply and glial support. Breast and renal tumors utilize an array of similar molecular signals to accomplish these tasks: such as the Ras/MEK/MAPK and PI-3K/Akt pathways. This may explain why these primaries have a preponderance to metastasize to the brain. As antioncogenic therapies become more effective and patients with systemic cancers are afforded longer survival, cerebral invasion becomes more common and more important to overall management. Based on recent scientific data, emerging therapeutic targets for brain metastasis include vascular endothelial growth factor (VEGF), the epidermal growth factor receptor (EGFR) family, chemokines and mTOR.