A glioblastoma is a cancerous brain tumor that develops from specific brain cells called astrocytes.
Glioblastomas are dangerous because they are very aggressive and difficult to remove. They quickly grow into the surrounding brain tissue.
The exact cause is unknown in most cases. Doctors use imaging tests and biopsies to make a diagnosis.
There is currently no cure for glioblastoma. Treatment focuses on slowing the growth of the cancer and improving the person’s quality of life.
Glioblastoma, also called glioblastoma multiforme, is a highly aggressive type of brain cancer.
Glioblastoma attacks specific cells in the brain called astrocytes, which are cells that play a role in supporting nerve cells in the brain and spinal cord.
A glioblastoma may contain different cell types, as well as areas of dead and decaying cells.
Glioblastomas are grade IV tumors, which means that they reproduce rapidly and aggressively. They can grow rapidly because they form their own new blood vessels to increase their blood supply.
Glioblastomas are also infiltrative, invading other cells in the brain.
Although they are most common in the cerebral hemispheres in the brain, they may occur anywhere in this organ. It is very rare for glioblastomas to spread outside the brain.
A glioblastoma may be either a primary or secondary tumor.
The most common types of glioblastomas are primary or de novo glioblastomas, meaning that they begin as a grade IV tumor with no earlier signs of grade I–III tumors in the area.
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De novo tumors tend to be more aggressive and affect older people. Glioblastomas may occur in anyone, however.
Secondary glioblastomas are tumors that progress from lower grade tumors. These tumors may change over time, becoming more aggressive as they progress.
In most cases, doctors do not know the underlying cause of glioblastomas.
The risk factors for glioblastoma are also difficult to determine. There appears to be a correlation between past exposure of the head or neck to radiation and glioblastoma in some cases. Experts have also associated some hereditary conditions with an increased risk of glioblastoma. These conditions include neurofibromatosis type 1, Li-Fraumeni syndrome, and Turcot syndrome.
The tumors may appear in anyone, but they are slightly more common in males and older people. The average age for a glioblastoma diagnosis is 64 years.
Glioblastomas are very aggressive, and people tend to develop symptoms very quickly as the tumor grows and causes brain swelling.
Symptoms that can arise from swelling and increased pressure in the brain include:
- nausea
- vomiting
- severe headaches
- seizures
- weakness
- fatigue
- trouble balancing
- vision issues, such as blurred or double vision
- memory issues
- trouble thinking
- difficulty speaking
- changes in personality
Depending on where the tumor is within the brain, a person may experience other symptoms.
A doctor can use several tools to diagnose a glioblastoma, including:
- a neurological exam
- imaging tests
- a biopsy
- molecular testing
During the neurological exam, the doctor will ask a person about their symptoms, such as issues affecting balance, strength, and muscle coordination. They may also ask about symptoms relating to the senses, including hearing or vision problems.
Imaging tests, such as MRI scans, can help doctors determine both the size and location of the tumor.
Doctors may perform a biopsy prior to surgery to remove and test a bit of the tumor. Doing this can help determine how aggressive the cancer is and the types of cells that it is affecting.
Other specialized tests may also provide details on the specific mutations in the cancer cells, which may affect a person’s treatment and outlook.
Brain cancers can be challenging to treat, partly due to the body’s blood-brain barrier, which is a membrane that separates the blood from the brain.
This barrier acts as a security system in most cases and prevents infectious germs and other harmful compounds in the blood from getting to the brain.
However, it also makes it very difficult to deliver cancer treatments to the brain. Drugs that are very small or can attach to specific cells in the blood can pass through the barrier, however.
Glioblastomas are especially challenging to treat. The tumor spreads out in a tentacle-like fashion, making it difficult to remove the entire growth.
Additionally, some malignant cells can have a similar appearance to healthy cells. As a result, even after removing all of the visible tumor, tiny portions of the tumor may still be there and start growing again after surgery.
There is no cure for glioblastoma, but doctors may be able to slow the growth of the tumor significantly and increase a person’s quality of life through a combination of treatment methods, such as:
Surgery
Surgery is the first line of treatment for a glioblastoma. The surgeon will remove as much of the tumor as possible.
Tumors that occur in high risk areas of the brain may not be possible to remove completely.
Radiation
Doctors use a short round of radiation to kill as many leftover cells as possible after the surgery.
Radiation may also slow the growth of tumor cells that surgeons could not remove.
Chemotherapy
Doctors may use chemotherapy drugs, such as temozolomide or carmustine, to support treatment.
Chemotherapy drugs may make other treatment options, such as radiation, more effective.
Electric field therapy
Electric field therapy or tumor treating fields may also help eliminate some tumor cells. This treatment involves placing electrodes on the scalp and sending electrical impulses into the brain to target tumor cells without affecting healthy cells.
Laser interstitial thermal therapy
Laser interstitial thermal therapy (LITT) is a newer treatment that doctors may recommend for the treatment of recurrent tumors that are hard to reach with surgery. This procedure involves a laser catheter, which surgeons implant in the tumor and heat to high temperatures to destroy cancer cells.
Major cancer centers may also offer other new or experimental therapies. In some cases, they may ask the person to participate in a clinical trial.
Glioblastoma is an aggressive brain cancer that has a generally poor outlook. There is no cure, and treatment focuses on slowing the progression rather than curing the cancer.
However, the way that cancer grows and mutates varies in each case.
The American Brain Tumor Association note that depending on the type of tumor and mutation, the median survival for adults with glioblastoma is between 11 and 31 months.
Individual survival rates can vary greatly depending on many factors, such as how much of the tumor surgeons could remove, how well the tumor responds to treatment, and the types of treatment available.
Receiving a cancer diagnosis can cause a range of emotions, including fear and anxiety. People can reach out to loved ones for support and ask their doctor about support groups for people with brain tumors.
Glioblastoma is a highly aggressive brain cancer that is difficult to treat. There is no cure, but treatment will focus on slowing the progression of the cancer.
Survival rates for glioblastoma are low, but a range of factors will determine an individual’s outlook.
New treatments are likely to aim to slow the progression further and increase survival rates.