Glioblastomas (GBM) are malignant Grade IV tumors where a large portion of tumor cells are reproducing and dividing at any given time. They are generally found in the cerebral hemispheres of the brain, but can be found anywhere in the brain. They are nourished by an ample and abnormal tumor vessel blood supply.

Glioblastomas are infiltrative and invade into nearby regions of the brain. They can also sometimes spread to the opposite side of the brain through connection fibers. Glioblastomas rarely spread outside of the brain.

Glioblastomas may arise “de novo,” meaning they begin as a Grade IV tumor with no evidence of a lower grade precursor. De novo tumors are the most common form of glioblastoma. They tend to be more aggressive and tend to affect older patients. Alternatively, secondary glioblastomas may progress from a lower-grade astrocytic tumors (Grade II or Grade III) and evolve into Grade IV tumors over time. In general, these tumors tend to be slower growing initially, but can progressively become aggressive.

Signs & Symptoms

Patients with glioblastomas develop symptoms rapidly due to mass effect from the tumor itself or from the fluid surrounding the tumor (edema) that causes further brain swelling.

  • Common symptoms related to the increased pressure in the brain:
    • Nausea
    • Vomiting
    • Severe headaches that are typically worse in the morning
  • Neurological symptoms dependent on the tumor location:
    • Weakness or sensory changes of face, arm or leg
    • Balance difficulties
    • Neurocognitive/memory issues
  • Another common symptom is seizures.


Glioblastoma can be difficult to treat since some cells may respond well to certain therapies and others may not. Because of this, the treatment plan for glioblastoma may combine several approaches.

  • Surgery. The first step in treating glioblastoma is a surgical procedure to make a diagnosis, to relieve pressure on the brain, and to safely remove as much tumor as possible. Glioblastomas are diffuse and have finger-like tentacles that infiltrate the brain, which makes them very difficult to remove completely. This is particularly true when the tumors are growing near important regions of the brain that control functions such as language and movement/coordination.
  • Radiation Therapy and Chemotherapy are used to slow down the growth of residual tumor after surgery and for tumors that cannot be removed with surgery. Additional treatments such as angiogenesis inhibitors may be used for tumors that recur or those that are non-responsive as a second-line agent.
  • Tumor Treating Fields may also be offered especially for recurrent tumors in adults.