Colonization of metastatic tumor cells in the brain. Overexpression of the adhesion molecules makes it easy for tumor cells to target and adhere to endothelial lining in the parenchyma, making it possible for these endothelial-adhesive interactions to enhance the possibility of brain metastasis. Direct neurotropic interactions with brain homing mechanisms result in BrM. “Vascular co-option” is the ability of metastatic cells to grow along the preexisting vessels, and once adherent to the VBM, tumor cells can extravasate into the parenchyma, the VBM thus being the “soil” for BrM.
