Glioblastoma: Signs and Treatment

Medically Reviewed by Jabeen Begum, MD on March 28, 2024
9 min read

Glioblastoma is a type of brain cancer. It’s the most common type of malignant brain tumor among adults, making up about half of all brain tumors in the U.S. Each year, about 12,000 people are diagnosed with glioblastoma. It's usually very aggressive, which means it can grow fast and spread quickly.

Despite a lot of research, there is no cure for glioblastoma, but there are treatments to help ease symptoms. People with glioblastoma who are not treated live an average of about 4 months. Those who do get treatment live for about 12 to 15 months.

Astrocytoma vs. glioblastoma

Astrocytomas are a type of brain cancer. Both astrocytomas and glioblastomas start in brain cells called astrocytes. These cells help give your brain the nutrients it needs. Glioblastomas used to be considered grade 4 astrocytomas, which meant that they were advanced, aggressive astrocytomas. Scientists changed the classification because they found there are molecules in the glioblastoma that aren’t in an astrocytoma. Although the classification may have changed, both glioblastomas and grade 4 astrocytomas are very aggressive brain tumors.

A glioblastoma is a type of astrocytoma, a cancer that forms from star-shaped cells in the brain called astrocytes. In adults, this cancer usually starts in the cerebrum, the largest part of your brain.

Glioblastoma tumors make their own blood supply, which helps them grow. It's easy for them to invade normal brain tissue.

Brain cancers and those affecting the central nervous system (CNS) are the fifth most common cancers in the U.S. Of the almost 90,000 brain tumors diagnosed in the U.S every year, about 12,000 of them are glioblastomas. Men and those assigned male at birth are more likely to get them than women and those assigned female at birth, and the risk goes up with age. 

Glioblastoma symptoms depend on where in the brain the tumor is. Because glioblastomas grow quickly, pressure on the brain usually causes the first symptoms. The tumor can cause:


Experts aren’t exactly sure what causes glioblastoma. But certain things may make you more likely to have one, such as:

Prior radiation to the head. If you previously got radiation to treat brain tumors or cancers that may have spread to the area, it can increase your risk of having a glioblastoma.

Exposure to chemicals and other cancer-causing agents may also increase your risk of genetic mutations.

Age and gender. It’s more common among those who are 50 or above. The average age at diagnosis is 64. Men are more likely to have it.

Race. It’s more common among White people than among Black, Asian, and Indigenous groups.

Is glioblastoma hereditary?

Your risk of glioblastoma may be greater if you have hereditary disorders linked to genetic mutations, such as:

There are two types:

Primary glioblastoma. It makes up around 90% of the cases. This type of tumor tends to be aggressive and grows fast. It’s more likely to affect older people. You’re also likely to have a shorter life expectancy.

Secondary glioblastoma. This type usually develops from a low-grade glioma – a type of tumor found in the brain or spinal cord. It’s more likely to affect younger people, and it’s usually in the frontal lobe of the brain. The survival rate for this type tends to be better than for primary glioblastoma.

If you have glioblastoma symptoms, your doctor will likely refer you to a neurologist (a doctor who specializes in diagnosing and treating brain disorders). Your neurologist will take your medical history and ask questions, like when your symptoms began, if anything makes them better, and more. The doctor will then will give you a neurological exam. This may include checking your:

  • Vision
  • Hearing
  • Balance
  • Reflexes
  • Strength
  • Coordination

You might then be sent for tests to check for a tumor, and if there is one, what type of tumor. 

You may get a magnetic resonance imaging test (MRI), computed tomography scan (CT scan), or positron emission tomography (PET). These are imaging tests that can help your neurologist see where the tumor is and how big it is. At this point, you will probably be referred to an oncologist, a cancer specialist.

Once it’s confirmed that there is a tumor, you will probably have a biopsy, a procedure where a surgeon removes a small bit of tissue from the tumor to send it to a lab for testing. The test results will show what type of tumor it is and how best to treat it.

Doctors don’t group glioblastoma by stages. Instead, they give all brain cancers a “grade.” It ranges from 1 to 4. The grade is based on how the cancer cells look under a microscope and how likely they are to reproduce. Glioblastomas are always recognized as grade 4 brain cancer. That’s because this type is very aggressive and the cancer cells multiply quickly.

Glioma is one the most common types of primary brain cancer. It’s an umbrella term for tumors that develop from glue-like cells known as glial cells that surround nerve cells in your brain or spinal cord.

Glioblastoma is a type of glioma. All advanced forms of glioma, also known as grade 4 glioma, are called glioblastoma, the most aggressive type of glioma.

There is no cure for glioblastoma, but treatment can often slow and control tumor growth. This will help you live as comfortably and as well as possible. There several types of treatments, and many people get more than one type:


Surgery is most often the first part of the treatment plan. A neurosurgeon, a surgeon who specializes in operating on the brain, tries to remove as much of the tumor as possible. Because glioblastomas often develop in healthy brain tissue, the neurosurgeon may not be able to remove all of the tumor. 


Radiotherapy or radiation therapy is usually the next step after surgery, typically about 6 weeks later. It is used to kill leftover tumor cells. It can also slow the growth of tumors that can't be removed by surgery. While radiation is usually done after surgery, if the tumor is too large or in a place that is too difficult to reach, it might be done instead of surgery.

If you are getting radiation for glioblastoma, you might also take a chemotherapy drug called temozolomide. The medication makes it easier for the radiation to work on the tumor. 


Like radiation therapy, chemotherapy for glioblastoma usually starts after surgery, but it might be given instead of surgery if operating on the tumor isn’t possible. 

The chemotherapy drug given most often, called the “gold standard,” is temozolomide, which you might be taking along with radiation therapy. 

The others that are used for treating glioblastoma are:

  • Carmustine, given intravenously (meaning directly into a vein, or by IV)
  • Bevacizumab, which is usually given if the first treatment doesn’t work well enough, is also given by IV.
  • Lomustine, which is taken along with bevacizumab, is a capsule taken by mouth. 

Targeted therapy 

Targeted therapy is treatment with medications that were developed to target specific proteins in a tumor. They are usually given if traditional chemotherapy doesn’t work or doesn’t work well enough. The chemotherapy drug bevacizumab (Avastin, Mvasi) is one targeted therapy, as is everolimus (Afinitor). Everolimus comes in a pill form.

Convection-enhanced delivery (CED) 

Convection-enhanced delivery (CED) uses a pump to release a slow, continuous stream of chemotherapy or targeted therapies to a tumor. This type of treatment allows doctors to go past the blood-brain barrier, blood vessels that protect the brain from harmful substances in the blood. The blood-brain barrier makes it hard for chemotherapy drugs to affect the tumors. CED allows the drug to reach the tumor directly.

Electric field therapy 

Electric field therapy uses electrical fields to target cells in the tumor while not hurting normal cells. To do this, doctors put four sets of electrodes directly on your scalp. The wearable device is called Optune. You get it with chemotherapy after surgery and radiation. The FDA has approved it for both newly diagnosed people and people whose glioblastoma has come back.

Wafer therapy

Wafer therapy (Gliadel) is a glioblastoma treatment that uses an implanted, biodegradable disk. The disk slowly dissolves, releasing the chemotherapy drug carmustine to target cancerous tissue that is left after surgery.

Nanoparticle therapy 

Nanoparticle therapy uses tiny particles to carry chemotherapy directly into the tumor. The nanoparticles stick to the tumor and slowly release the drugs. It’s a new treatment and is another way to bypass the blood-brain barrier.

Glioblastoma treatment research continues

There may be experimental treatments or oral chemotherapy, which you take at home, available at major cancer centers.

These treatments may help with symptoms and possibly put the cancer into remission in some people. In remission, symptoms may let up or disappear for a time.

Glioblastomas often regrow. If that happens, doctors may be able to treat it with surgery and a different form of radiation and chemotherapy.

There are also ongoing clinical trials that are trying new treatments. If you are interested in learning more about clinical trials, ask your oncologist for information to see if you qualify for any.

Palliative care

Palliative care is an important type of care for anyone with a serious illness. It is not the same thing as hospice care, which provides comfort at the end of life. Instead, palliative care provides you with medications and other treatments for comfort, to manage side effects of your cancer treatment, and improve your quality of life. Palliative care also includes taking care of the emotions you may be dealing with.

Many things can affect how well someone does when they have cancer, including glioblastomas. Doctors often can’t predict what someone’s life expectancy will be if they have a glioblastoma. But they do have statistics that track how large groups of people who’ve had these conditions tend to do over time.

For glioblastoma, the survival rates are:

  • One year: 25%
  • Two years: 8-12%
  • Five years: 5%

These numbers can’t predict what will happen to an individual, though. A person’s age, type of tumor, and overall health play a role. As treatments improve, people newly diagnosed with these aggressive brain tumors may have a better outcome.

Unfortunately, researchers don’t yet know of any way to prevent glioblastoma, but they have found that having had ionizing radiation therapy to treat other types of cancer could increase your risk. This is especially important if you’ve had the treatment targeting your neck or head.

Living with a brain tumor is challenging. Both the symptoms and the treatments can make you feel uncomfortable and lower your quality of life. Depending on where the tumor is, you might find it hard to speak or have trouble walking or seeing. Your moods may be all over the place and your personality can change. It can also be hard on loved ones and friends. But there is help available to help you navigate this.

Support groups

Support groups can help if you have glioblastoma or you know someone who does. By speaking with others, you’ll learn that you’re not alone and others have gone through the same thing. People in the support groups can just listen, or they can offer practical help, such as sharing how they managed certain symptoms or glioblastoma treatment side effects. Support groups can be in-person or online.

Counseling or therapy

You can see a counselor or therapist alone or with your family. Most oncology clinics will be able to refer you to a qualified counselor or therapist. You can also ask your doctor’s office if they recommend therapists.

Clinical trials

Clinical trials are another way you can try to get treatment for your glioblastoma. There are many ongoing trials for treatment. Ask your oncologist if there are any trials you might qualify for.

Glioblastomas are aggressive brain tumors that affect about half of all people with a brain tumor. There is no cure yet, but there are glioblastoma treatments that can help improve your quality of life and help you live longer. Ongoing research has found newer treatments along with the traditional surgery, chemotherapy, and radiation therapy.

What is the life expectancy with glioblastoma?

The average life expectancy of someone with glioblastoma is about 12 to 15 months with treatment. Without treatment, it is about 4 months.

Has anyone survived a glioblastoma?

There have been a few exceptions of people with glioblastoma who lived for many years after the tumor was removed from their brain. There have also been a few people who survived for more than 3 years, but this isn’t common.

Who is at most risk for glioblastoma?

Other than knowing that people who received ionizing radiation therapy are at a higher risk of getting glioblastoma, researchers don’t know of any other risk factors.