Introduction

Primary brain tumors are neoplasms that originate from brain cells. In 2005, approximately 44 000 primary brain tumors were newly diagnosed and about 13 000 deaths were attributed to these types of tumors in the United States (1). They account for 1.4% of all cancers and 2.4% of all cancer-related deaths.

Our knowledge of brain tumors has expanded in recent years with new findings in tumor molecular genetics and biology. A greater appreciation of the singular nature of glioma in particular has become better appreciated, and new and important questions have arisen and begun to be addressed. For example, there is now compelling data supporting the concept of cancer stem cells in glioma and ideas concerning the identity of the tumor cell of origin have emerged. Physiologically relevant animal models have been developed that may reveal new insights into the etiology and development of these tumors. Innovative improvements in live imaging, neurosurgery, radiation, and chemotherapy have significantly extended survival time for patients with particular tumor types. In this chapter, we will briefly compare the characteristics of major brain neoplasms and describe recent advances in brain tumor research with an emphasis on potential therapies for malignant astrocytomas, the most common and most lethal brain tumor type.