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Anaplastic astrocytoma is a rare WHO grade III type of astrocytoma of the brain.
The annual incidence rate is 0.44 per 100,000 people.
Patients usually present with headache, depression, focal neurological deficits, and/or seizures.
The mean interval between onset of symptoms and diagnosis is approximately 1.5-2 years.
The mean interval between onset of symptoms and diagnosis is intermediate between that of low-grade astrocytomas and glioblastomas.
Seizures are less common among patients with anaplastic astrocytomas than with low-grade lesions.
Most cases occur sporadically or without identifiable cause.
Less than 5% of patients with malignant astrocytoma has a definite or suspected hereditary predisposition:
neurofibromatosis type I, Li-Fraumeni syndrome, hereditary nonpolyposis colorectal cancer and tuberous sclerosis.
Anaplastic astrocytomas also associated with previous exposure to vinyl chloride and to high doses of radiation therapy to the brain.
Anaplastic astrocytomas are high grade gliomas (WHO grade III-IV), which are pathologically undifferentiated gliomas that carry a poor clinical prognosis.
Anaplastic astrocytomas are grade III malignant tumors.
They grow more rapidly than lower grade tumors.
Anaplastic astrocytomas recur more frequently than lower grade tumors because their tendency to spread into surrounding tissue makes them difficult to completely remove surgically.
Compared to glioblastoma, anaplastic astrocytomas lack vascular proliferation and necrosis on pathologic study.
Histologically, compared to grade II tumors, anaplastic astrocytomas are more cellular, demonstrate increased atypia, and mitoses
Surgical treatment is to remove as much of the tumor as possible without worsening neurologic deficits.
Radiation therapy prolongs survival and is a standard component of treatment.
No proven benefit with adjuvant chemotherapy.
Temozolomide is effective for treating recurrent anaplastic astrocytoma.
Depending on the area of involvement of the brain patina may experience: paralysis, speech impediments, difficulties planning and skewed sensory perception.
The age-standardized 5-year relative survival rate is 23.6%.
Patients with anaplastic astrocytoma are 46 times more likely to die than matched members of the general population.
The elderly are much more likely to die in the first year post-diagnosis when compared to young adults, but after three years, this difference is reduced markedly.
Typical median survival for anaplastic astrocytoma is 2-3 years.
Progression to glioblastoma multiforme is common.
More resistant to chemotherapy than is anaplastic oligodenroglioma.
Median age is 45 years.
Median survival two to three years.
Toleration of chemotherapy combined with radiotherapy is reduced in the elderly.
In a phase 3 trial comparing temozolomide alone versus radiotherapy alone in elderly patients with anaplastic astrocytoma or glioblastoma: temozolomide alone is non inferior to radiotherapy alone in this study (Neuro-oncology Working Group).
In the above study tumor MGMT promoter methylation was seen in 35% of patients tested and MGMT promoter methylation was associated with a longer overall survival than was the unmethylated status,11.9 versus 8.2 months.
In the above study event free survival was longer in patients with MGMT promoter methylation who received temozolomide than in those who underwent radiotherapy, 8.4 months versus 4.6 months, whereas the opposite was true for patients with no methylation of the MGMT promoter 3.3 months versus 4.6 months.
The median survival rate of patients with anaplastic astrocytoma who undergo both resection and irradiation has been reported to be twice that of patients receiving only operative therapy (5 y vs 2.2 y).