Q&A: Understanding glioblastoma (GBM)

If you’ve been diagnosed with glioblastoma (GBM), you might have questions about treatment options. While glioblastoma is an aggressive tumor, there are many advances and treatment plans that can be tailored to a patient’s specific needs.

Neuro-oncologist Vinay Puduvalli, M.D., answers common questions about glioblastoma and what’s next in patient care.

What is glioblastoma?

Glioblastoma is a highly malignant brain tumor that starts and grows in the brain. It belongs to the glioma tumor group, specifically under the subtype of astrocytomas. Astrocytomas are graded on a scale of one to four, with four being the most aggressive tumor. This grade is also known as glioblastoma.

Does glioblastoma occur in a certain part of the brain?

Although glioblastoma can happen anywhere in the brain, it usually forms in the frontal lobe and the temporal lobe. Glioblastoma can rarely occur in the brain stem or spinal cord.

Are there any known causes or risks factors for glioblastoma?

There is no direct risk factor associated with most cases of glioblastoma. Certain rare genetic diseases, such as Li-Fraumeni and Lynch syndrome, are associated with gliomas. However, these affect only a small portion of patients with glioblastoma. Besides genetic syndromes, the only well-established risk factor is prior exposure to ionizing radiation that is used to treat certain head and neck cancers.

What are common symptoms of glioblastoma?

Brain tumor symptoms vary and depend on the tumor location. The most common glioblastoma symptoms are:

• headaches
• seizures
• progressively worsening numbness or weakness

Headaches with red flag symptoms warrant a trip to the doctor for a neurologic evaluation. Red flag symptoms include:

• waking up due to pain,
• worsening pain on changing position, and/or
• continuous pain not relieved with over-the-counter headache medications) warrant a trip to the doctor for a neurologic evaluation.

How is glioblastoma diagnosed?

Neurologic imaging with an MRI of the brain is often the first step. Brain imaging showing contrast-enhancing masses can be suggestive of glioblastoma.

Most cases can be definitively diagnosed after surgery through histological testing. This takes place when a neuropathologist examines tissue or cells under a microscope to help confirm a glioblastoma diagnosis.

What are the treatment options for glioblastoma?

Standard treatment for glioblastoma starts with surgery. The goal is to safely remove as much of the tumor as possible. After surgery, patients typically receive radiation therapy simultaneously with temozolomide, a type of chemotherapy. Afterward, patients continue to be treated with a recommended six cycles of temozolomide.

Patients may also be treated with tumor treatment fields. This is a portable device placed on the scalp that uses mild electrical fields to interrupt cancer cell growth.

Clinical trials are also an option for many patients.

A patient’s care team will take into account age, functional status, medical history and medication tolerability when planning the best treatment.

What clinical trials are available for glioblastoma?

There are many clinical trials available for glioblastoma here at MD Anderson. We offer several through our Glioblastoma Moon Shot®, which enables us to test new therapies and identify better treatment approaches to improve patients’ lives. Clinical trials are available for patients who have newly diagnosed, recurrent or progressive disease. The treatments offered through these clinical trials include new chemotherapy drugs, immunotherapy, targeted therapies, vaccines, oncolytic viral therapies, and new surgical techniques such as Laser Interstitial Thermal Therapy (LITT), and combinations of these treatments.

The blood-brain barrier is the interface between brain blood vessels and the surrounding brain tissue, which is made up of tightly arranged cells and membranes that keep harmful substances in the blood from reaching the brain. But when it comes to brain tumor treatment, physicians are looking for ways to access the blood-brain barrier to target tumors. New types of chemotherapy that penetrate the blood-brain barrier are being actively studied.

MD Anderson researchers are also conducting non-treatment clinical trials that focus on fitness and well-being to improve a patient’s quality of life.

Why is glioblastoma typically hard to treat?

As glioblastoma grows, it spreads into the surrounding brain. This makes it difficult to remove the entire tumor with surgery. Although radiation therapy and chemotherapy can reach the tumors, glioblastoma cells can survive and regrow. Glioblastoma can be very challenging to treat due to tumor-specific features, such as its rapid growth rate, the poor function of the immune system cells within the tumor, and inherent resistance of the tumor cells to many types of treatments.

And some treatments may not be as effective due to factors such as the patient’s age, functional status, co-existing medical conditions and the genetic subtypes of tumors that differ from one person to another.

What advances have been made in glioblastoma care?

Recent advances include testing to identify unique mutations associated with each patient’s tumor. This allows us to sometimes identify targeted therapy for patients based on their specific mutations. Several new combination therapies are being tested in clinical trials; these may target glioblastomas better than only one type of treatment.

What’s your advice for someone recently diagnosed with glioblastoma?

The first step is to seek help early from glioblastoma specialists. There’s a lot of information about glioblastoma online, but a glioblastoma specialist will be able to help you really weigh all of your options as you navigate your diagnosis so you can make the best decisions for you. . Glioblastoma is a highly complex disease, so it’s important to see someone who really understands it and has treated many cases. A specialist can talk to you about all of your possible treatment options from the beginning, including what your options may be down the line if the initial treatments don’t work.