Over time, cancer cells can break off from a primary tumor in another part of the body, such as the lungs, and travel to the brain. The cancer cells can travel to the brain through your lymph system or your bloodstream. The tumor that then grows in the brain looks and is treated like the tumor that started in another part of the body, like the lungs. Metastatic brain tumors are becoming more common because people are living longer after having cancer somewhere else in their body.
In most cases, the metastatic brain tumor is found in the cerebrum. This is the outer part of the brain that controls your thoughts, emotions, and language ability. It's also involved in movement and sensing the outside world. But metastasis can be found in other areas of the brain, too.
Metastatic brain tumors are most common in people with lung cancer. Other types of cancer that tend to metastasize to the brain include melanoma, kidney cancer, and breast cancer.