What Are Metastatic Brain Tumors?

Metastatic brain tumors, also called brain metastases, are tumors that form when cancer cells spread to the brain from another part of the body. These tumors are different from primary brain tumors because they did not start in the brain.

A metastatic brain tumor keeps the identity of the original cancer. For example, lung cancer that spreads to the brain is still considered metastatic lung cancer, not a new primary brain cancer. Common cancers that may spread to the brain include lung cancer, breast cancer, melanoma, kidney cancer, and colorectal cancer.

De Novo Brain & Spine evaluates adult patients with suspected or confirmed metastatic brain tumors to help determine whether neurosurgical treatment may be appropriate. Evaluation may include neurological examination, brain MRI, CT imaging, review of cancer history, tissue diagnosis when needed, surgical consultation, and coordination with oncology, radiation oncology, or other specialists.

Common Signs and Symptoms

Metastatic brain tumor symptoms depend on the number of tumors, tumor size, location in the brain, swelling around the tumor, and effect on nearby brain tissue. Some brain metastases are found during cancer surveillance imaging before symptoms develop.

Common signs and symptoms may include:

• Persistent or worsening headaches
• Headaches with nausea or vomiting
• New-onset seizures
• Weakness, numbness, or tingling in the face, arm, or leg
• Trouble speaking, understanding speech, or finding words
• Vision changes, including blurred vision, double vision, or loss of part of the visual field
• Balance problems, dizziness, or trouble walking
• Memory problems, confusion, or difficulty concentrating
• Personality changes, mood changes, or behavior changes
• Fatigue, drowsiness, or decreased alertness
• Symptoms related to brain swelling, also called vasogenic edema

Seek emergency medical care or call 911 for a first-time seizure, sudden weakness, sudden speech difficulty, sudden vision loss, severe confusion, loss of consciousness, or a rapidly worsening headache with vomiting or neurological changes.

What Causes This Condition?

Metastatic brain tumors are caused by cancer cells spreading to the brain from a cancer that began somewhere else in the body. This process is called metastasis.

Important facts about causes and risk factors include:

• Brain metastases may occur in people with a known cancer diagnosis
• In some cases, a brain metastasis may be found before the original cancer site is known
• Cancers that may spread to the brain include lung cancer, breast cancer, melanoma, kidney cancer, colorectal cancer, and other malignancies
• Cancer cells may travel through the bloodstream and form tumors within brain tissue
• The likelihood of brain metastases depends on the type of primary cancer, tumor biology, stage of disease, and response to cancer treatment

Metastatic brain tumors are not caused by head injury, routine daily activity, or lifestyle factors alone. Treatment planning depends on the primary cancer type, brain imaging findings, neurological symptoms, systemic disease status, and the patient’s overall health.

How It Is Diagnosed?

Metastatic brain tumors cannot be diagnosed by symptoms alone. Diagnosis usually requires neurological evaluation, brain imaging, and review of the patient’s cancer history. Tissue testing may be needed in selected cases.

Common diagnostic steps may include:

• Medical history and neurological examination to evaluate strength, sensation, reflexes, speech, vision, coordination, balance, memory, and cognitive function
• Review of cancer history, including the primary cancer type, prior treatments, current cancer status, and systemic disease burden
• MRI of the brain with and without contrast, often the main imaging study used to evaluate suspected brain metastases
• CT scan of the head, especially in urgent situations or when MRI is not immediately available
• Advanced MRI techniques when needed to clarify tumor location, swelling, bleeding, or surgical planning
• Body imaging, such as CT, PET/CT, or other oncology-directed studies, when needed to evaluate cancer outside the brain
• Stereotactic brain biopsy when diagnosis is uncertain or when tissue is needed to guide treatment
• Image-guided craniotomy and tumor resection when surgery is appropriate for diagnosis, tumor removal, or relief of pressure
• Pathology review to confirm whether the brain tumor matches the suspected primary cancer
• Molecular or biomarker testing when needed to help oncology determine systemic therapy options

The goal of diagnosis is to confirm whether the brain lesion is metastatic cancer, identify the primary tumor when needed, understand the number and location of brain metastases, and determine whether surgery, radiation, systemic therapy, or supportive care may be appropriate.

Treatment Options

Metastatic brain tumor treatment depends on the primary cancer type, number of brain metastases, size and location of tumors, symptoms, swelling, prior treatments, systemic disease status, neurological examination, surgical risk, and the patient’s overall health and goals of care.

Treatment options may include:

• Corticosteroids, such as dexamethasone, when brain swelling is causing symptoms or pressure
• Anti-seizure medication when seizures have occurred or when clinically appropriate
• Stereotactic radiosurgery, also called SRS, for selected brain metastases where focused radiation is appropriate
• Whole-brain radiation therapy, also called WBRT, in selected cases depending on the number of tumors, cancer type, symptoms, and treatment goals
• Image-guided craniotomy for tumor resection when surgery is appropriate to remove a tumor, relieve pressure, obtain tissue diagnosis, or address a large symptomatic lesion
• Maximal safe resection, which means removing tumor while protecting important brain functions such as speech, movement, vision, memory, and sensation
• Postoperative radiation therapy or stereotactic radiosurgery when recommended after surgical removal to help manage the treated tumor area
• Systemic therapy, such as chemotherapy, targeted therapy, immunotherapy, or other drug therapy, when recommended by oncology based on cancer type and molecular findings
• Observation with repeat imaging in selected situations when lesions are small, asymptomatic, or being managed as part of an oncology-directed plan
• Treatment for recurrent or progressive brain metastases, which may include repeat surgery, radiation, systemic therapy, clinical trial discussion, or supportive care depending on the case
• Rehabilitation and supportive care to help with strength, balance, speech, cognition, seizures, headaches, or daily function

Surgery is not appropriate for every metastatic brain tumor. Neurosurgical treatment may be considered when a lesion is large, symptomatic, causing mass effect, causing swelling, creating diagnostic uncertainty, or located where removal may help relieve pressure or support the next stage of cancer treatment.