What is metastatic brain cancer?

Cancer cells that develop in a body organ such as the lung (primary cancer tissue type) can spread via direct extention, or through the lymphatic system and/or through the bloodstream to other body organs such as the brain. Tumors formed by such cancer cells that spread (metastasize) to other organs are called metastatic tumors. Metastatic brain cancer is a mass of cells (tumor) that originated in another body organ and has spread into the brain tissue. Metastatic tumors in the brain are more common than primary brain tumors. They are usually named after the tissue or organ where the cancer first developed (for example, metastatic lung or breast cancer tumors in the brain, which are the most common types found). Occasionally, an abbreviated name may be used that often confuses people; for example, "small cell brain cancer" actually means "small cell lung cancer that has metastasized to the brain." People should not hesitate to ask their doctor about any terms they do not understand.

What causes brain cancer?

Primary brain tumors arise from many types of brain tissue (for example, glial cells, astrocytes, and other brain cell types). Metastatic brain cancer is caused by the spread of cancer cells from a body organ to the brain. However, the causes for the change from normal cells to cancer cells in both metastatic and primary brain tumors are not fully understood. Data gathered by research scientists show that people with certain risk factors are more likely to develop brain cancer.
Individuals with risk factors, such as having a job in an oil refinery, handlers of jet fuel or chemicals like benzene, chemists, embalmers, or rubber-industry workers, show higher rates of brain cancer than the general population. Some families have several members with brain cancer, but heredity as a cause for brain tumors has not been proven. Other risk factors such as smoking, radiation exposure, and viral infection (HIV) have been suggested but not proven to cause brain cancer. There is no good evidence that brain cancer is contagious, caused by head trauma, or caused by cell phone use. Although many lay press and web articles claim that aspartame (artificial sweetener) causes brain cancer, the FDA maintains that it does not cause brain cancer and base their findings on over 100 toxicological and clinical studies regarding the sweetener's safety.