Metastatic Disease of the Nervous System.

Nervous system metastases occur in about 25% of patients with systemic cancer (Table 1) and usually involve the brain parenchyma, leptomeninges, and spinal epidural space. Although they are ominous, they can be effectively treated in many patients, reducing disability and prolonging life. Treatment may include surgery, and radiation therapy and chemotherapy are often necessary. The choice of agents is often made on the basis of the primary tumor. Even when sustained remission cannot be achieved, effective palliation can be accomplished in most patients.