A changing paradigm of glioma biology

The past 30 years have witnessed a major paradigm shift in brain tumor research with the development of a wide variety of molecular biology techniques. These methods have permitted a better understanding of the pathogenesis of gliomas including the finding of neural stem cells that contribute to the establishment and continuous population of brain tumors. Molecular biology has contributed to our understanding of prognosis in these tumors with findings of genetic correlations to patient age, response to treatment, and outcome. Gene therapy has been made possible by molecular techniques that contribute to new treatment options. Nevertheless, if these advances are to make substantial clinical improvements, attention must be paid to issues of tumor evolution, local versus general pathogenesis, tumor heterogeneity, both general and regional, and the development of resistance to treatment. Appropriate clinical trials will be needed to test these new findings.