Gliomas have a tendency to infiltrate other areas and they are often inaccessible to surgery. On the positive side, much higher survival rates can be achieved in certain low-grade brain cancers, particularly those that occur in the cerebellum, and the survival rate has considerably improved over the past twenty years for both children and adults. Progress has been made specifically for medulloblastomas in both children and adults and nonmalignant astrocytomas and oligodendrogliomas in adults. When brain tumors grow large enough or if they cause secondary conditions that result in the displacement of structures in the brain, acute life-threatening syndromes can occur. Symptoms of emergency syndromes may include pupil dilation, a fixed gaze, paralysis on one or both sides of the body, and blindness or defective vision in one eye.
Prompt intervention is essential.
In general, physicians use a set of criteria to determine prognosis of a primary brain tumor, including its cell type and grade, its size, the extent of cancer infiltration into healthy tissue, the patient's age and ability to function, and the duration of symptoms. Some primary low-grade brain tumors are curable by surgery alone, and some are curable by surgery and radiotherapy. The remainder requires surgery, radiotherapy, chemotherapy, and possibly investigational treatments. Tumors that require three or more treatment modalities are rarely curable. Malignant primary brain tumors are classified according to tumor grade.