Brain metastases are a common complication of primary cancers and a significant cause of morbidity and mortality – the rates of disease and death in certain populations – according to the American Association of Neurological Surgeons [1]. These tumors do not start in the brain, but occur when cancer cells break away from a cancer in another area of the body and travel to the brain [2] [3] [4].Unlike normal cells, cancerous cells can break off from a tumor and travel through the bloodstream or the body’s lymph system.
In the case of metastatic brain tumors, the cancer cells travel and spread to the brain. This spreading of the primary cancer is known as “metastasizing”. For example, when lung cancer metastasizes to the brain, this “brain cancer” is actually made up of lung cancer cells. It sounds odd, but if a pathologist were to look at the brain metastasis tissue under a microscope, it would look like lung cancer cells.
Among types of primary tumors, lung cancers are responsible for the highest number of brain metastases [5] [6] [7]. Other cancers that commonly metastasize to the brain are melanoma (skin cancer) as well as breast, colon and kidney cancer, but any type of cancer could potentially spread to the brain.
[1] http://www.aans.org/Patient%20Information/Conditions%20and%20Treatments/Brain%20Metastasis.aspx
[2] Poste, G. & Fidler, I. The pathogenesis of cancer metastasis. Nature 283, 139 (1980).
[3] Tosoni, A., Ermani, M. & Brandes, A. a. The pathogenesis and treatment of brain metastases: a comprehensive review. Crit. Rev. Oncol. Hematol. 52, 199–215 (2004).
[4] Raizer, J. J. & Abrey, L. E. Brain metastases. Book (Springer Science+Business Media, 2007).
[5] Sawaya, R. E. Intracranial Metastases. Book (Blackwell Publishing, Inc., 2004). doi:10.1002/9780470753064
[6] Kim, D. & Lunsford, L. Current and Future Management of Brain Metastasis. Book 25, (Karger Publishers, 2012).
[7] Raizer, J. J. & Abrey, L. E. Brain metastases. Book (Springer Science+Business Media, 2007).
