Clinical and experimental aspects of human glioma

Thomas, D.G.T., Department of Neurological Surgery, Institute of Neurology, London, WCIN 3BG.,~.K. Primary brain tumours are the tenth most common malignant tumours in man, with peak age incidence in childhood and middle age. Such tumours arise from glial cells and may be astrocytomas, oligodendrogliomas or ependymomas. Astrocytomas are the mos~ common and may arise anywhere in the brain, although frontal temporal and parietal sites are most frequent. The most important factors which determine the outcome of the patient are the histological grade of the tumour and his age. Site within the brain, and extent of surgical removal have relatively little effect on outcome. In high grade astrocytomas average survival is about 6 months, while in low grade tumours it may be many years. There is considerable heterogeni~y in the cells of one individual tumour, and between cells of tumours of a common his÷ological type and grade. However, it is clear that there are quantitative biochemical differences between low and high grade tumours. For ex~aple, the amount of glisl f ibri l lary acidic protein in astrocytoma is inversely proportional to their malignancy, in high grade tumours there is a change of oxygen and glueose metabol ism from aerobic to anaerobic metabolism, and the cell kinetics of the tumour cell population changes with anaplasia. Such findings indicate that an ders dSng f dSfferent 'at ion rolif ra ion in the t an forme astrQcyte wo~id u s e ~ . i n D~armlng new ~orms o~nlh~rapy ~y {coal &dmlnis~ra~lon o~ agenzs caoaole Ol mOGlly lng znese processes.