Glioblastoma (GBM) is the most common and aggressive primary brain tumor in adults. While the prognosis has historically been poor, multimodal treatment (surgery, radiation, chemotherapy, and emerging therapies) and newer technologies like tumor treating fields (TTF) are improving outcomes. This is a serious diagnosis requiring multidisciplinary care at a specialized center.

What Is Brain Cancer?

Brain tumors originate from brain cells (not metastases from other cancers). Glioblastoma arises from glial cells (astrocytes), which support and protect neurons. It's a grade IV (highest grade) tumor, meaning it grows and spreads rapidly.

Key fact: Glioblastoma can be primary (develops from scratch) or secondary (from lower-grade glioma that progresses). Molecular markers (IDH mutation status, MGMT methylation, TP53) increasingly guide treatment.

Types of Brain Tumors

  • Glioblastoma (Grade IV astrocytoma): Most aggressive. Requires maximum safe surgery, radiation, and chemotherapy.
  • Lower-grade gliomas (Grade II-III): Slower growing but still serious. Treatment depends on grade and molecular features.
  • Other primary brain tumors: Meningiomas, ependymomas, medulloblastomas (mostly pediatric). Each has different prognosis and treatment.

Risk Factors

  • Prior head radiation: Most well-established risk factor.
  • Genetic syndromes: Neurofibromatosis type 1, tuberous sclerosis, Li-Fraumeni syndrome increase risk.
  • Age: Can occur at any age; glioblastoma peaks in 45-70 year-olds.
  • Immunosuppression: HIV+ individuals have higher risk.

Note: Despite popular misconception, cell phone use is not established as a risk factor.

Symptoms

Symptoms depend on tumor location and size. Common symptoms include:

  • Persistent headaches (often morning headaches)
  • Seizures (20-40% of patients)
  • Vision or speech problems
  • Balance or coordination difficulty (ataxia)
  • Numbness or weakness (often on one side)
  • Cognitive changes (memory, concentration)
  • Nausea and vomiting
  • Personality changes or behavioral changes

Important: Symptoms depend on tumor location. A small tumor in a critical area may cause more symptoms than a large tumor elsewhere.

Diagnosis

Diagnostic tools:

  • MRI with contrast: Gold standard. Shows tumor location, size, and extent.
  • CT scan: May show calcifications or bone involvement.
  • Biopsy or surgical resection: Only way to definitively diagnose and grade tumor. Often done during surgery.
  • Molecular testing: IDH status, MGMT methylation, TP53 mutation, EGFR amplification guide prognosis and treatment.

Staging & Grading

Brain tumors use WHO grading (I-IV) rather than typical TNM staging:

  • Grade I-II: Low-grade, slower growing.
  • Grade III: Intermediate (anaplastic astrocytoma).
  • Grade IV: Glioblastoma, most aggressive, rapid growth.

IDH-mutant tumors have better prognosis than IDH-wildtype tumors.

Treatment Options

Maximal Safe Surgical Resection

Removing as much tumor as possible while preserving brain function. Intraoperative monitoring and imaging (awake craniotomy, neuronavigation) maximize resection while minimizing deficits. Extent of resection correlates with survival.

Radiation Therapy

Standard therapy post-surgery. Focal radiation to tumor and margin. Typical dose 60 Gray over 6 weeks. Newer techniques (IMRT, proton therapy) focus dose on tumor while sparing normal brain.

Chemotherapy

Temozolomide (TMZ): Standard chemotherapy during and after radiation. Oral medication, generally well tolerated. Given concurrently with radiation, then adjuvant cycles.

Tumor Treating Fields (TTF)

FDA-approved device (Optune) that delivers electric fields to tumor. Worn as head cap. Used with chemotherapy. Improves progression-free and overall survival.

Immunotherapy & Investigational Approaches

Checkpoint inhibitors and CAR-T therapy are under investigation. Some trials showing promise; not yet standard but increasingly available.

Supportive Care

Antiepileptic drugs (if seizures), corticosteroids (reduce brain swelling), anticoagulation (if blood clots), rehabilitation (physical/speech therapy).

Side Effects & Survivorship

From surgery: Temporary or permanent neurological deficits (weakness, speech changes, cognitive changes), hemorrhage, infection.

From radiation: Fatigue, hair loss (localized), cognitive decline (may be delayed, months to years later), radiation necrosis (tissue damage), secondary malignancy (rare but possible).

From chemotherapy: Nausea, bone marrow suppression, liver/kidney toxicity.

Long-term: Cognitive impairment is common (from tumor, surgery, and radiation). Neuropsychological rehabilitation, occupational therapy, and support are important.

Prognosis

Glioblastoma has serious prognosis, but has improved over time:

  • Median overall survival: 12-15 months with standard treatment (surgery, radiation, TMZ).
  • With TTF: May extend to 16-20 months.
  • IDH-mutant glioblastoma: Better prognosis, median 3+ years.
  • Younger patients: Often have better outcomes than older patients.

Long-term survivorship (5+ years) is possible but uncommon. Focus shifts to quality of life and maintaining function.

Seek Immediate Care If You Experience:

  • New seizure activity or status epilepticus (prolonged seizure)
  • Acute severe headache with fever or stiff neck (infection)
  • Sudden severe neurological changes (weakness, vision loss, speech problems)
  • Signs of brain herniation (altered consciousness, unequal pupils, herniation breathing pattern)

Key Questions for Your Doctor

  • What are my tumor's molecular features (IDH status, MGMT, TP53)?
  • How much tumor can be safely resected?
  • What is the extent of resection plan?
  • What is my expected radiation and chemotherapy regimen?
  • Am I a candidate for TTF (Optune)?
  • Are there clinical trials available?
  • What rehabilitation and cognitive support is available?
  • What is my expected prognosis and survival estimate?