The development of brain metastases is still considered as a "terminal complication" of a cancer disease. The potential for CNS metastases appears to be greatest in tumours of neuroectodermal origin like melanoma or SCLC, very high in patients with tumours of ectodermal origin like breast cancer and NSCLC, whereas tumours arising from other embryonic origin develop brain metastases less
Brain metastases are the most common form of brain cancer, occurring in about 25% of all patients with cancer. Typical primary tumours with brain metastases are lung, breast, melanoma, and kidney.
The rapid development of targeted therapies capable of entering the brain and the emerging technology of nano shells armed with cytotoxins reflects promising progress in the treatment of brain metastasis.