Brain Metastases
Brain metastases are secondary tumors that form when a cancer from another part of the body spreads to the brain. They are the most common group of intracranial tumors in adults and are far more frequent than primary brain tumors. Treatment requires a multidisciplinary approach tailored to the type of primary cancer and the features of the metastases.
Última atualização: 2026-06-06
Definition
Brain metastases are secondary tumors that form when a primary cancer elsewhere in the body spreads to the brain through the bloodstream. They do not originate from the brain tissue itself. In adults they make up a significant proportion of all intracranial tumors and are notably more common than primary brain tumors.
Epidemiology and Source Cancers
The cancers that most often metastasize to the brain are lung cancer, breast cancer and melanoma; less frequently, kidney (renal cell) and colorectal cancers can also spread to the brain. In some cases the primary cancer is unknown. Metastases are usually located in the cerebral hemispheres at the gray-white matter junction. A substantial proportion of cases have multiple metastases. As advances in cancer treatment allow patients to live longer, the incidence of brain metastases has increased.
Symptoms
Symptoms vary with the location and number of metastases. Common features include progressive headache (often worse in the morning), nausea and vomiting from raised intracranial pressure, location-dependent limb weakness or sensory loss, visual field loss, epileptic seizures, and cognitive and behavioral changes.
Diagnosis
Contrast-enhanced brain MRI is the most sensitive imaging method; metastases typically appear as well-defined, often ring-enhancing masses surrounded by edema and are frequently multiple. If the primary cancer is unknown, whole-body staging (such as PET-CT, chest-abdomen-pelvis CT) is performed. For a single (solitary) lesion, surgical resection provides both tissue diagnosis and removal of the mass and aids differential diagnosis. When leptomeningeal spread is suspected, spinal MRI and cerebrospinal fluid cytology are considered.
Prognostic Assessment
Prognosis depends on the type and molecular features of the primary cancer, the number of metastases, the patient's performance status, and whether extracranial disease is controlled. Tools that combine these factors, such as the cancer-specific Diagnosis-Specific Graded Prognostic Assessment (DS-GPA), are used to estimate the expected course and to plan treatment. Outcomes have improved markedly in recent years for cases that respond to targeted therapy and immunotherapy.
Treatment Options
Treatment is planned by medical oncology, radiation oncology and neurosurgery working together. The first step is usually a steroid (dexamethasone) to reduce edema. For a limited number of metastases, local treatments are preferred: surgical resection for large, symptomatic lesions, and stereotactic radiosurgery (Gamma Knife, CyberKnife) for small to moderate or multiple lesions. For widespread disease, whole-brain radiotherapy may be considered; hippocampal-sparing techniques can be used to reduce cognitive side effects. Systemic treatment (chemotherapy, targeted agents, immunotherapy) is chosen according to the molecular profile of the primary cancer and plays an increasingly important role.
Prognosis
The course in patients with brain metastases varies widely. Long-term control may be achievable with modern treatments in patients with a single metastasis, good performance status and a targetable molecular feature, whereas prognosis is more limited in patients with widespread disease and poor performance status. Treatment is individualized; outcomes vary from patient to patient and no outcome can be guaranteed.
Referências
- Greenberg MS. Greenberg's Handbook of Neurosurgery. 10th ed. Thieme; 2023:908.
- Osborn AG, Hedlund GL, Salzman KL. Osborn's Brain: Imaging, Pathology, and Anatomy. 2nd ed. Elsevier; 2018:835.
- Vogelbaum MA, et al. Treatment for Brain Metastases: ASCO-SNO-ASTRO Guideline. J Clin Oncol. 2022.
- NCCN Clinical Practice Guidelines in Oncology — Central Nervous System Cancers.
Este artigo é informativo e não substitui um exame médico. As decisões de diagnóstico e tratamento são individuais.