Glioblastoma

Glioblastoma is a fast-growing brain tumor that starts in the brain's supportive cells, called astrocytes. It's the most common and aggressive primary brain tumor in adults, with about 12,000 new diagnoses each year. It usually affects the brain rather than the spinal cord and can grow quickly into nearby healthy tissue. You may also hear it called GBM, glioblastoma multiforme, or grade IV astrocytoma. 

Types and Stages

Glioblastoma isn't classified by stages. Instead, brain tumors are "graded" by how abnormal the cells look and how fast they're likely to grow. The scale runs from I to IV.

All glioblastomas are grade IV under the World Health Organization (WHO) system. This is because:

• The cells look highly abnormal and share little with healthy cells.
• They grow and spread quickly, often invading nearby brain tissue.
• They form their own blood vessels and may contain calcium or cystic material.

Signs and Symptoms 

Symptoms can include:

• Headaches, often worst in the morning
• Nausea and vomiting
• Confusion or trouble thinking and understanding
• Memory loss
• Personality changes or irritability
• Vision changes, such as blurred or double vision
• Speech difficulties
• Trouble with balance or coordination
• Muscle weakness in the face, arms, or legs
• Reduced sense of touch
• Seizures, especially new ones

Diagnosis

Doctors use several tests to diagnose glioblastoma:

• Neurological exam. Checks vision, hearing, balance, coordination, strength and reflexes. Problems can point to the affected part of the brain.
   
• Imaging tests. MRI is used most often to find the tumor's size and location. A dye injection may be given for clearer pictures. CT and PET scans may also be used.
   
• Biopsy. A tissue sample is removed with a needle or during surgery and tested in a lab to confirm whether the cells are glioblastoma.

Treatment 

There's no cure for glioblastoma, but treatments can slow its growth and ease symptoms. Options include:

• Surgery. A neurosurgeon removes as much of the tumor as safely possible. Because glioblastoma grows into healthy tissue, some cells may remain. Surgery isn't always possible if the tumor is too deep.
   
• Radiation therapy. Often used after surgery to target remaining cells. It may be combined with chemotherapy, or used as the main treatment when surgery isn't an option.
   
• Chemotherapy. Strong medicines, often taken as a pill, are used after surgery and alongside radiation. Other forms may be given through a vein, or as dissolving wafers placed in the brain during surgery.
   
• Tumor treating fields (TTF). Sticky pads on the scalp deliver electrical fields that make it harder for tumor cells to multiply. TTF works with chemotherapy and may follow radiation.
   
• Targeted therapy. Medicines that attack specific chemicals in cancer cells. Testing your cells can show if this may help, often when the tumor can't be fully removed or comes back.

Causes and Risk Factors 

The cause of most glioblastomas is unknown. Factors that may raise the risk include:

• Age. Most common in older adults, but it can happen at any age.
   
• Radiation exposure. Ionizing radiation, such as past radiation therapy, can increase risk.
   
• Inherited syndromes. Conditions like Lynch syndrome and Li-Fraumeni syndrome can run in families. Genetic testing can detect them.

Screening

There is no routine screening for glioblastoma. Diagnosis depends on noticing symptoms and seeking prompt medical care.