Glioblastoma (GBM)

Glioblastoma, formerly known as glioblastoma multiforme, is the most common and aggressive type of primary brain cancer in adults. It starts in brain cells called astrocytes. The cancer cells grow rapidly, pressing on brain tissue. This leads to symptoms like persistent headaches, nausea and vomiting, and seizures.

Astrocytes are a type of glial cell. So, glioblastomas (GBMs) belong to a broader group of brain tumors called gliomas. Glioblastomas are grade 4 gliomas. This is the highest grade, which means they’re the fastest-growing glioma.

There’s no cure for glioblastoma. Even with treatment, the average survival timeline is 15 months after diagnosis. Still, no two diagnoses are the same. Your cancer care team will let you know what to expect based on your situation.

Symptoms of glioblastoma

Glioblastoma symptoms tend to come on quickly — over days or weeks. They can vary based on where the tumor forms in your brain. Symptoms usually result from the tumor pressing on and damaging brain tissue.

GBM symptoms may include:

• Persistent headaches: This may be one of your first symptoms. Headaches are often worse in the morning and may become more severe over time. You may develop nausea and vomiting alongside headaches.
• Balance issues: You may fall more often and have difficulty walking.
• Vision and hearing changes: You may have blurred vision, double vision or hearing loss.
• Memory and thinking problems: You may have sudden confusion, difficulty concentrating and memory loss.
• Mood or personality changes: You may have mood swings and become impulsive.
• Weakness: You may have muscle weakness or numbness in one part of your body.
• Seizures: It may be the first seizure you’ve ever had or may be different from seizures you’ve had.
• Speech problems: You may have slurred speech or difficulty finding the right words to use.

See a healthcare provider right away if you have any of these symptoms.

Glioblastoma causes

Experts don’t know the exact cause of glioblastomas. But like all cancers, GBMs form when mutations (changes) to certain genes cause cells to multiply too fast. Eventually, they form tumors.

Glioblastomas grow especially fast. The tumor can press on and damage brain tissue and invade other areas of your brain.

Is glioblastoma hereditary?

It’s possible to inherit genetic mutations from your biological parents that lead to tumors. But inherited GBMs are rare. Most commonly, the mutations that lead to glioblastoma happen randomly during your lifetime.

Risk factors

Risk factors for glioblastoma include:

• Age: You can get glioblastoma at any age. But the risk goes up as you get older. It most often affects people ages 45 to 70. The average age at diagnosis is 64.
• Radiation exposure: Ionizing radiation exposure to your head, like from prior cancer treatment, is one of the most significant risk factors.
• Sex: Males are slightly more likely to get it than females.
• Certain genetic conditions: Having a tumor-causing condition, like neurofibromatosis, Li-Fraumeni syndrome or Turcot syndrome, increases your risk.

Complications

Within months, glioblastoma can lead to complications, such as:

• Increasing confusion
• Profound memory loss
• Difficulty moving
• Speaking and swallowing problems
• Frequent seizures
• Loss of bowel and bladder control
• Need for around-the-clock care

Treatments can also cause side effects and complications. In many cases, glioblastoma results in death.

How doctors diagnose glioblastoma

A healthcare provider will ask about your symptoms and do a neurological exam. If they suspect you may have a brain tumor, you’ll need imaging tests, like an MRI or CT scan.

The only way to confirm a glioblastoma diagnosis is to get a biopsy (sample) of the tumor to examine its cells.

Through this cell examination and testing, your care team will learn more about the specifics of the tumor. This information helps determine the best treatment for it. Terms you may hear your provider use include:

• Primary or secondary: Primary GBM (most common) develops from neural stem cells. Secondary GBM develops from mature astrocytes.
• IDH-wildtype: All glioblastomas are IDH-wildtype. IDH is a gene that can become mutated and lead to gliomas. IDH-wildtype means that this gene isn’t affected.
• Other gene names: Other mutated genes may include EGFR, TP53, PDGFRA and NF1.

Staging and grades

Glioblastomas don’t have a staging system because they typically start and stay in your brain. Staging applies to cancers that have the potential to spread to other parts of your body.

Grades describe the aggressive nature of tumors. All GBMs are automatically grade 4, the highest grade. They’re the most aggressive form of gliomas.

How is it treated?

There’s no cure for glioblastoma. So, the goal of treatment is to prevent further damage to your brain and control tumor growth. Managing your quality of life is also key.

Surgery to remove as much of the tumor as possible is the go-to treatment, followed by radiation and chemotherapy. Sometimes, surgery isn’t a safe option, or total tumor removal isn’t possible.

Together, you and your care team will decide on a plan that’s tailored to your needs and goals.

Glioblastoma treatment options include:

• Craniotomy: Your surgeon opens your skull to remove the tumor.
• Radiation therapy: X-rays damage cancer cells. Standard radiation also damages nearby tissue. Intensity-modulated radiation therapy (IMRT) delivers radiation to the tumor while sparing healthy brain tissue.
• Chemotherapy: Medications kill cancer cells. Your provider will likely recommend both chemo and radiation.
• Stereotactic radiosurgery (Gamma Knife®): Focused energy beams target the tumor with minimal damage to healthy tissue. Providers often use this if GBM returns after IMRT.
• Laser interstitial thermal therapy (LITT): A surgically based treatment uses laser-generated heat to kill tumor cells.
• Targeted therapy: Drugs target certain cell changes that fuel cancer growth. It’s an alternative to chemotherapy.
• Tumor treatment fields (TTF): Low-intensity electric fields hit the tumor via scalp electrodes and disrupt cancer cell growth. You may get it after chemo and radiation.
• Immunotherapy: Drugs use your body’s immune system to fight the GBM cells.
• Clinical trials: You may be able to try experimental treatments for glioblastoma.
• Palliative care: This is an extra layer of support on top of the cancer care you already receive. It provides symptom relief and emotional support. Your loved ones can get this support as well.

Each of these treatments has potential risks and complications. For example, surgical site infections are common with multiple surgeries. And chemotherapy and radiation have various side effects.

We understand that this can be a lot to take in. Lean on your care team for guidance — each case is different. They’ll use the latest research to offer you the best treatment options.

What can I expect if I have glioblastoma?

A glioblastoma diagnosis may feel overwhelming. There’s a lot to learn and consider in a short amount of time.

Your care team will help you decide on the best treatment plan for your situation. It may involve aggressive treatment to extend your life and/or therapies that manage symptoms and help you feel better.

Glioblastoma may result in early death shortly after a diagnosis without treatment.

With treatment, your outlook depends on several factors. For example, if your surgeon can completely remove the tumor, your outlook may be better than in cases of partial removal. Your overall health is another consideration.

Glioblastoma can also come back (recur) after treatment.

Life expectancy

Most people live an average of 15 months after a glioblastoma diagnosis. It’s less if you don’t have treatment. The five-year survival rate for glioblastoma is under 10%. That means fewer than 1 in 10 people with GBM are alive five years after their diagnosis.

Remember, though, that survival rates are estimates. They can’t tell you how long you’ll live or how you’ll respond to treatment. Also, the numbers are based on past information. They don’t account for the impact new treatments — and clinical trials — can have on your outlook. This is why your healthcare provider is your best resource to explain your prognosis.

Can this be prevented?

Genetic mutations (changes) that cause glioblastoma aren’t preventable. But early detection and treatment may slow the progression of a tumor.

If brain tumors run in your biological family, you may want to consider genetic testing. Talk to a healthcare provider or a genetic counselor to learn whether this testing is right for you.