|Classification and external resources|
Anaplastic astrocytomas fall under the category of high grade gliomas (WHO grade III-IV), which are pathologically undifferentiated gliomas that carry a poor clinical prognosis. Unlike glioblastomas (WHO grade IV), anaplastic astrocytomas lack vascular proliferation and necrosis on pathologic evaluation. Compared to grade II tumors, anaplastic astrocytomas are more cellular, demonstrate more atypia, and mitoses are seen.
Initial presenting symptoms most commonly are headache, depressed mental status, focal neurological deficits, and/or seizures. The growth rate and mean interval between onset of symptoms and diagnosis is approximately 1.5–2 years but is highly variable, being intermediate between that of low-grade astrocytomas and glioblastomas. Seizures are less common among patients with anaplastic astrocytomas compared to low-grade lesions.
Most high-grade gliomas occur sporadically or without identifiable cause. However, a small proportion (less than 5%) of persons with malignant astrocytoma has a definite or suspected hereditary predisposition. The main hereditary predispositions are mainly neurofibromatosis type I, Li-Fraumeni syndrome, hereditary nonpolyposis colorectal cancer and tuberous sclerosis. Anaplastic astrocytomas have also been associated with previous exposure to vinyl chloride and to high doses of radiation therapy to the brain.
The standard initial treatment is to remove as much of the tumor as possible without worsening neurologic deficits. Radiation therapy has been shown to prolong survival and is a standard component of treatment. There is no proven benefit to adjuvant chemotherapy or supplementing other treatments for this kind of tumor. Although temozolomide is effective for treating recurrent anaplastic astrocytoma, its role as an adjuvant to radiation therapy has not been fully tested.
Quality of life after treatment depends heavily on the area of the brain that housed the tumor. In many cases, patients with anaplastic astrocytoma may experience various types of paralysis, speech impediments, difficulties planning and skewed sensory perception. Most cases of paralysis and speech difficulties can be rehabilitated with speech, occupational, physical, and vision therapy.
Typical median survival for anaplastic astrocytoma is 2-3 years. Secondary progression to glioblastoma multiforme is common. Radiation, younger age, female sex, treatment after 2000, and surgery were associated with improved survival in AA patients.
- Astrocytoma; Author: Benjamin Kennedy, Columbia University College of Physicians and Surgeons; Coauthor(s): Jeffrey N Bruce, MD, Edgar M Housepian Professor of Neurological Surgery Research, Professor of Neurological Surgery, Director of Brain Tumor Tissue Bank, Director of Bartoli Brain Tumor Laboratory, Department of Neurosurgery, Columbia University College of Physicians and Surgeons; Jan 23 2009, http://emedicine.medscape.com/article/283453-overview
- Children's Hospital Boston > Anaplastic Astrocytoma. Retrieved on August 2010
- Malignant astrocytomas By Edward J Dropcho MD. Contributing editor: Dr. Dropcho. Originally released November 11, 1996; last updated December 7, 2009
- Nuño M, Birch K, Mukherjee D, Sarmiento JM, Black KL, Patil CG. Survival and prognostic factors of anaplastic gliomas. Neurosurgery. 2013 Sep;73(3):458-65. doi: 10.1227/01.neu.0000431477.02408.5e. PubMed PMID: 23719055.