glioblastoma

Overview
Glioblastoma (also called glioblastoma multiforme or GBM) is an aggressive and fast-growing type of brain cancerthat begins in glial cells, which support and protect neurons. It’s the most common malignant primary brain tumor in adults. GBM typically affects the cerebrum, the largest part of the brain, and tends to infiltrate surrounding brain tissue, making it extremely difficult to remove completely. Its rapid growth and location in the brain contribute to severe neurological symptoms and a poor prognosis.

Why It’s Important
Glioblastoma is highly lethal and requires immediate medical attention. Even with surgery, radiation, and chemotherapy, survival rates are low, with most patients surviving only 12 to 18 months after diagnosis. Because it affects essential brain functions—like movement, speech, memory, and behavior—it often leads to a significant loss of independence and quality of life. Early detection and multidisciplinary care can slightly improve outcomes.

Quick Facts

  • Affects mostly adults aged 45 and older, but can occur at any age

  • More common in men than women

  • Accounts for nearly 48% of all malignant brain tumors

  • Always considered grade IV (most aggressive) by the WHO

  • Rarely spreads outside the brain or spinal cord

  • Has a poor prognosis, with a 5-year survival rate under 10%

What Happens in the Body
Glioblastoma originates in the astrocytes, star-shaped glial cells in the brain. The tumor grows rapidly and forms irregular projections that invade healthy brain tissue. It creates new blood vessels to feed its growth (angiogenesis) and often causes swelling (edema) in the brain. This disrupts normal brain function, increases intracranial pressure, and can cause widespread neurological impairment. It rarely metastasizes outside the central nervous system but aggressively spreads within the brain.

Common Signs and Symptoms
Symptoms vary depending on the tumor’s location but may include:

  • Persistent headaches, often worse in the morning

  • Nausea and vomiting

  • Seizures, especially in adults without a history of epilepsy

  • Cognitive decline, memory loss, or confusion

  • Speech difficulties or trouble understanding language

  • Personality changes or mood swings

  • Weakness or numbness on one side of the body

  • Vision problems or double vision

Diagnosis

  • MRI with contrast (preferred imaging method)

  • CT scan if MRI isn’t available

  • Biopsy or surgical resection to confirm tumor type and grade

  • Molecular testing for gene mutations (e.g., IDH, MGMT, EGFR) that can affect prognosis and treatment

See a doctor if:

  • You experience new or worsening neurological symptoms

  • You have unexplained seizures, vision issues, or headaches

  • You’ve had a prior brain tumor or radiation exposure

Treatment and Management

  • Surgery: Aim is to remove as much of the tumor as possible (debulking)

  • Radiation therapy: Typically follows surgery to slow tumor regrowth

  • Chemotherapy: Most commonly temozolomide (Temodar)

  • Tumor-treating fields (TTF): A wearable device that uses electrical fields to disrupt cancer cell division

  • Clinical trials: May include immunotherapy, gene therapy, or targeted drugs

  • Treatment is not curative—it focuses on extending survival and improving quality of life

Risks and Complications

  • Rapid recurrence even after treatment

  • Severe cognitive and motor impairments

  • Depression, anxiety, and personality changes

  • Swelling of the brain due to tumor or treatment side effects

  • Shortened lifespan, typically within 1–2 years

Who Is at Risk

  • Older adults, especially over age 50

  • Men more than women

  • People with certain genetic syndromes (e.g., Li-Fraumeni, Turcot syndrome)

  • Previous radiation therapy to the head

  • No clear environmental cause in most cases

Related Conditions

  • Other gliomas (astrocytoma, oligodendroglioma)

  • Seizure disorders

  • Hydrocephalus (fluid buildup in the brain)

  • Brain metastases from other cancers

When to See a Doctor

  • If you have new or worsening headaches, especially with other neurological symptoms

  • If you develop sudden seizures

  • If you or a loved one is experiencing rapid personality or cognitive changes

  • If you have a family history of brain tumors or genetic cancer syndromes

Last Updated: July 30, 2025