Glioblastoma

What is Glioblastoma?

Glioblastoma, also called GBM or glioblastoma multiforme, is an aggressive malignant brain tumor and high-grade glioma. It can grow into nearby brain tissue and may affect areas that control speech, movement, vision, memory, balance, behavior, and personality.

In current medical classification, adult glioblastoma is usually described as glioblastoma, IDH-wildtype, CNS WHO grade 4. This means the diagnosis is based not only on how the tumor looks under the microscope, but also on molecular testing. Important markers may include IDH status, MGMT promoter methylation, EGFR amplification, TERT promoter mutation, and chromosome 7 gain/chromosome 10 loss.

De Novo Brain & Spine evaluates patients with suspected or confirmed glioblastoma using neurological examination, brain MRI, and tissue diagnosis when appropriate. Treatment may involve biopsy, image-guided craniotomy, maximal safe brain tumor resection, radiation therapy, temozolomide chemotherapy, tumor treating fields, clinical trials, and coordinated neuro-oncology care.

Common Signs and Symptoms

Glioblastoma symptoms depend on the tumor’s size, location, growth pattern, and swelling around the tumor. Symptoms may develop gradually or appear suddenly.

Common signs and symptoms may include:

• Persistent or worsening headaches
• Headaches with nausea or vomiting
• New-onset seizures
• Weakness, numbness, or tingling on one side of the body
• Trouble speaking, understanding words, or finding the right words
• Vision changes, including blurred vision, double vision, or loss of part of the visual field
• Balance problems, dizziness, or trouble walking
• Memory loss, confusion, or difficulty concentrating
• Personality changes, mood changes, or behavior changes
• Fatigue, drowsiness, or decreased alertness

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

What Causes This Condition

Most glioblastomas are sporadic, meaning they develop without a clear inherited cause. In many patients, there is no known preventable reason why the tumor formed.

Possible risk factors may include:

• Older age, although glioblastoma can occur in adults of different ages
• Prior therapeutic radiation exposure to the head or brain
• Rare inherited cancer syndromes, such as Li-Fraumeni syndrome or Lynch syndrome

Doctors may also review molecular and genetic tumor features to better classify the glioblastoma and guide treatment planning. These may include IDH-wildtype status, MGMT promoter methylation, EGFR amplification, TERT promoter mutation, and chromosome 7 gain/chromosome 10 loss.

Glioblastoma is not usually caused by a head injury, routine daily activity, or a single lifestyle factor. Diagnosis and treatment decisions depend on imaging, pathology, molecular testing, neurological function, and the patient’s overall health.

How It Is Diagnosed

Glioblastoma cannot be diagnosed by symptoms alone. Diagnosis usually requires a combination of medical history, neurological examination, brain imaging, and tissue testing.

Common diagnostic steps may include:

• Medical history and neurological examination to evaluate strength, sensation, reflexes, vision, speech, coordination, balance, memory, and cognitive function
• MRI of the brain with and without contrast, the main imaging study used to evaluate a suspected brain tumor
• CT scan of the head, often used in urgent situations or when MRI is not immediately available
• Advanced MRI techniques, such as MRI perfusion, MR spectroscopy, functional MRI, or diffusion tensor imaging when needed for surgical planning
• Stereotactic brain biopsy when tissue is needed but the tumor cannot be safely removed
• Image-guided craniotomy and brain tumor resection when maximal safe tumor removal is appropriate
• Neuropathology review to confirm tumor type, tumor grade, and microscopic features
• Molecular testing, which may include IDH status, MGMT promoter methylation, EGFR amplification, TERT promoter mutation, chromosome 7 gain/chromosome 10 loss, and other markers when appropriate

These results help the care team understand the tumor type, confirm the diagnosis, plan treatment, and determine whether surgery, radiation, chemotherapy, clinical trials, or other therapies may be appropriate.

Why Is Molecular Testing Part of Glioblastoma Evaluation?

Molecular testing examines certain biological features of tumor tissue. These findings provide information beyond what can be seen on a brain scan or under a microscope alone.

Healthcare professionals may consider molecular results together with pathology, imaging, neurological findings, and medical history to develop a more complete understanding of the tumor. The specific tests performed can vary depending on the individual case and available tissue.

Treatment Options

Glioblastoma treatment is individualized. The right plan depends on the tumor’s size, location, molecular profile, symptoms, neurological examination, surgical risk, age, overall health, and goals of care.

Treatment options may include:

• Symptom management, including corticosteroids to reduce brain swelling, anti-seizure medication when seizures occur, pain control, and rehabilitation therapy
• Stereotactic biopsy to obtain tissue when the tumor is not safely removable or when diagnosis is uncertain
• Image-guided craniotomy for brain tumor resection to remove as much tumor as safely possible while protecting important brain functions
• Maximal safe resection, which means removing as much tumor as possible without causing unnecessary injury to speech, movement, vision, memory, or other neurological functions
• Functional brain mapping or awake brain mapping when the tumor is near areas that control language, movement, or other critical functions
• Radiation therapy, often used after surgery or biopsy to treat remaining tumor cells
• Temozolomide chemotherapy, an oral chemotherapy commonly used with radiation and afterward in eligible patients
• Tumor treating fields, also called TTFields, which may be considered for selected patients as part of ongoing treatment
• Clinical trials, especially when standard treatment options are limited or when molecular testing suggests a possible research-based therapy
• Treatment for recurrent glioblastoma, which may include repeat surgery, focused radiation in selected cases, chemotherapy, bevacizumab, clinical trials, or supportive care
• Palliative and supportive care to help manage symptoms, preserve function, and support quality of life during treatment

Surgery is not appropriate for every patient with glioblastoma. When surgery is considered, the goal is usually to obtain a diagnosis, reduce tumor burden, relieve pressure on the brain, and preserve neurological function as safely as possible.

Frequently Asked Questions

Is glioblastoma the same thing as brain cancer in general?

Glioblastoma is one specific type of primary brain tumor, meaning it starts in the brain itself rather than spreading there from another part of the body. Not every brain tumor is glioblastoma. Tumors that spread to the brain from cancer elsewhere in the body are called metastatic brain tumors, and they are evaluated and treated differently even though some symptoms can look similar.

Does a glioblastoma diagnosis always mean immediate surgery?

Not always. Some patients undergo image-guided surgery to remove as much of the tumor as safely possible, while others have a biopsy first if the tumor’s location makes full removal higher risk. The right approach depends on the tumor’s size, location, and the patient’s neurological exam and overall health, which is why evaluation comes before any treatment decision.

What happens after a glioblastoma diagnosis is confirmed?

After diagnosis, care usually involves a coordinated team that may include neurosurgery, radiation oncology, and neuro-oncology, working together on a treatment plan specific to the tumor’s molecular features and the patient’s health. This is typically when decisions about surgery, radiation, chemotherapy, or clinical trial options are discussed.

Is it possible to get a second opinion on a glioblastoma diagnosis or treatment plan?

Yes. A second opinion can help confirm a diagnosis, review imaging and pathology findings, or discuss treatment options before moving forward. Many patients and families find this a helpful step when facing a new brain tumor diagnosis.