Metastatic brain tumors are cancer that has spread (metastasized) to the brain from a primary cancer elsewhere in the body. They typically come from the lung, but can originate in other places as well. About one-third of people with another type of cancer will develop a metastasis in the brain. These can be quite difficult to treat.
Signs and symptoms can vary considerably based on the location, size and growth rate of the brain metastases. Typical signs and symptoms include headache, vomiting and a disturbance of consciousness. These are caused by the expansion of the lesions and increased intracranial pressure, which can be exacerbated by other factors, including the weight of the head, dehydration and certain medications.
A physical exam is usually performed, followed by one or more imaging tests to identify the lesion. Magnetic resonance imaging (MRI) is commonly used to detect brain tumors and to evaluate the extent of their spread. Occasionally, a biopsy may be necessary to obtain a tissue sample for evaluation and confirm the diagnosis. This is especially important when a patient is experiencing headaches, as a biopsy of the brain is more reliable than just relying on imaging.
MRI technology is rapidly improving. For example, a new technique called diffusion tensor imaging allows physicians to visualize the way water molecules move within the brain tissue and identify areas of abnormal cell density, which can indicate early infiltration of cancer cells. Other promising imaging technologies include cellular and molecular MRI and optical coherence tomography (OCT), which enable the detection of very small changes in brain tissues and can help with diagnosis.
Researchers are also developing new ways to improve treatment of brain metastases, notably through the use of immunotherapy. Several immunotherapy drugs currently in clinical trials are designed to stimulate your own immune system to better fight cancer in the brain. Many of these therapies target proteins (called checkpoint proteins) that cancer cells use to evade the immune response. By blocking these proteins, these drugs can allow your immune system to attack and destroy the cancer cells.
Memorial Sloan Kettering has a multidisciplinary team of experts who can evaluate and recommend a treatment plan for your brain metastases. This team includes a neurosurgeon, radiation oncologist and medical oncologist. Depending on your needs, the team will formulate a personalized treatment strategy for you. This strategy will likely involve surgery and/or radiation therapy, combined with medications that can target specific cancer cells or block their growth. These medicines include targeted therapy and chemotherapies, which can be given alone or with radiation.