Anaplastic oligoastrocytoma, or anaplastic astrocytoma, is a malignant tumor of the brain. It is more precisely a glioma, that is to say a tumor resulting from the nervous tissue, in the brain or the spinal cord. The World Health Organization classifies gliomas from I to IV, depending on their morphology and degree of malignancy. Anaplastic astrocytomas represent grade III, between grades I and II considered benign and glioblastomas (grade IV). Anaplastic astrocytoma can either be a complication of a benign grade II tumor or develop spontaneously. He has a strong tendency to progress to glioblastoma (grade IV) and life expectancy is around two to three years, despite treatment with surgery and radiotherapy / chemotherapy. Anaplastic astrocytomas and glioblastomas affect 5 to 8 in 100 people in the general population. (000)

Most symptoms of anaplastic oligoastrocytoma result from increased pressure in the brain, caused either by the tumor itself or by the abnormal buildup of cerebrospinal fluid it causes. Symptoms vary depending on the exact location and size of the tumor:

• Memory impairment, personality changes and hemiplegia when the tumor grows in the frontal lobe;
• Seizures, impaired memory, coordination and speech when in the temporal lobe;
• Motor disturbances and sensory abnormalities (tingling and burning) when it is in the parietal lobe;
• Visual disturbances when the tumor involves the occipital lobe.

The precise cause of anaplastic astrocytoma is not yet known, but researchers believe that it results from a combination of a genetic predisposition and environmental factors triggering the disease.

Anaplastic oligoastrocytoma is somewhat more common in men than women and often occurs between the ages of 30 and 50. It should be noted, however, that the disease is likely to affect children, usually between 5 and 9 years old. Anaplastic astrocytomas and multiform glioblastomas (grades III and IV) represent approximately 10% of childhood tumors in the central nervous system (80% of these tumors being grade I or II). (1)

Hereditary genetic diseases such as neurofibromatosis type I (Recklinghausen’s disease), Li-Fraumeni syndrome, and Bourneville tuberous sclerosis increase the risk of developing an anaplastic astrocytoma.

As with many cancers, environmental factors such as exposure to ultraviolet rays, ionizing radiation and certain chemicals, as well as poor diet and stress are considered to be risk factors.

The treatment of anaplastic oligoastrocytoma depends essentially on the general condition of the patient, the location of the tumor and the speed of its progression. It involves surgery, radiotherapy and chemotherapy, alone or in combination. The first step is to perform a surgical removal of as large a part of the tumor as possible (resection), but this is not always possible due to the parameters mentioned above. After surgery, radiation therapy and possibly chemotherapy are used to try to remove tumor residue, for example if the malignant cells have spread into brain tissue.

The prognosis is linked to the patient’s state of health, the characteristics of the tumor, and the body’s response to chemotherapy and radiotherapy treatments. Anaplastic astrocytoma has a strong tendency to progress to glioblastoma in about two years. With standard treatment, the median survival time for people with an anaplastic astrocytoma is two to three years, which means that half of them will die before this time. (2)