Anaplastic astrocytoma

Anaplastic astrocytoma (AA), also known as grade 3 astrocytoma (WHO grade III), is a malignant primary brain tumor that arises from star-shaped glial cells called astrocytes. It is classified as a diffuse, infiltrative high-grade glioma and represents an intermediate stage between lower-grade diffuse astrocytomas and glioblastoma (grade IV). Anaplastic astrocytomas primarily affect the central nervous system, most commonly occurring in the cerebral hemispheres, though they can develop in any part of the brain or spinal cord. The tumor is characterized by increased cellularity, nuclear atypia, and significant mitotic activity compared to lower-grade astrocytomas. Key symptoms depend on the tumor's location and size and may include headaches (often worse in the morning or with changes in position), seizures, focal neurological deficits such as weakness or numbness on one side of the body, speech difficulties, personality or cognitive changes, memory problems, and visual disturbances. Increased intracranial pressure from tumor growth can cause nausea, vomiting, and altered consciousness. Symptoms may develop gradually over weeks to months, though some patients present more acutely. The current treatment approach for anaplastic astrocytoma typically involves maximal safe surgical resection followed by radiation therapy and adjuvant chemotherapy, most commonly with temozolomide. Molecular markers, particularly IDH1/IDH2 mutation status and 1p/19q codeletion status, are now critical for classification and have significant prognostic implications. IDH-mutant anaplastic astrocytomas generally carry a more favorable prognosis than IDH-wildtype tumors. Despite treatment, anaplastic astrocytomas have a tendency to recur and may progress to glioblastoma over time. Median survival varies considerably based on molecular subtype, ranging from approximately 3-5 years for IDH-mutant tumors to shorter survival for IDH-wildtype tumors. Clinical trials investigating targeted therapies, immunotherapies, and novel treatment combinations are ongoing.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

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