DefinitionA metastatic brain tumor is cancer that started in another part of the body and spread to the brain.Alternative NamesBrain tumor - metastatic (secondary); Cancer - brain tumor (metastatic)Causes, incidence, and risk factorsMany tumor or cancer types can spread to the brain, the most common being lung cancer, breast cancer, melanoma, kidney cancer, bladder cancer, certain sarcomas, and testicular and germ cell tumors. Some types of cancers only spread to the brain infrequently, such as colon cancer, or very rarely, such as prostate cancer.Growing brain tumors may place pressure on nearby parts of the brain. Brain swelling due to these tumors also causes increased pressure within the skull.Metastatic brain tumors are classified depending on the exact site of the tumor within the br