Astrocytoma is a type of primary central nervous system (CNS) tumor that originates from astrocytes, which are star-shaped glial cells in the brain and spinal cord. Astrocytomas are classified by the World Health Organization (WHO) grading system (Grade I–IV) based on histologic features and aggressiveness:
- Grade I (Pilocytic astrocytoma): Usually benign, slow-growing, often seen in children, can sometimes be cured with surgical resection alone.
- Grade II (Diffuse astrocytoma): Low-grade, infiltrative, risk of progression to higher grades.
- Grade III (Anaplastic astrocytoma): Malignant, higher proliferative activity, usually treated with surgery + radiation ± chemotherapy.
- Grade IV (Glioblastoma, GBM): Highly aggressive, poor prognosis, standard treatment includes maximal surgical resection, radiotherapy, and concurrent/adjuvant temozolomide.
Pharmacist-relevant points:
- Chemotherapy options depend on grade, molecular markers (IDH mutation, MGMT methylation, 1p/19q codeletion), and patient age/performance status.
- Common agents include temozolomide, lomustine (CCNU), and sometimes bevacizumab in recurrent cases.
- Supportive care involves managing cerebral edema (dexamethasone), seizures (antiepileptics), and treatment-related toxicities.
| Grade / Type | Typical Age / Location | Biologic / Molecular Markers | Standard Treatment | Key Pharmacologic Considerations |
|---|---|---|---|---|
| Grade I – Pilocytic Astrocytoma | Children/young adults; cerebellum most common | Usually BRAF mutation/fusion | Surgical resection (often curative) | Rarely requires chemo; monitor post-op edema (dexamethasone) |
| Grade II – Diffuse Astrocytoma | Young adults; cerebral hemispheres | IDH-mutant common; 1p/19q intact | Surgery ± radiation; chemo (temozolomide) if progression | Temozolomide myelosuppression; monitor liver function, blood counts |
| Grade III – Anaplastic Astrocytoma | Adults; cerebral hemispheres | IDH-mutant or wildtype | Surgery + radiation + chemotherapy (temozolomide or PCV: procarbazine, CCNU, vincristine) | Chemotherapy toxicities: myelosuppression, neuropathy (vincristine), nausea (procarbazine); manage cerebral edema with steroids |
| Grade IV – Glioblastoma (GBM) | Adults; cerebral hemispheres | IDH-wildtype common; MGMT promoter methylation predicts temozolomide response | Maximal resection + radiotherapy + concurrent/adjuvant temozolomide | Temozolomide: myelosuppression, nausea; corticosteroids for edema; monitor for infection; consider seizure prophylaxis |
Additional pharmacist notes:
- Steroid use (dexamethasone) is frequent—monitor glucose, GI protection, infection risk.
- Seizure prophylaxis may involve levetiracetam (preferred due to minimal drug interactions).
- Drug interactions: Temozolomide has minimal CYP interactions but consider additive myelosuppression with other agents.
- Supportive care: Anti-emetics (5-HT3 antagonists) for chemotherapy-induced nausea, growth factors if prolonged neutropenia occurs.