Brain Tumor - Glioblastoma
There are two main categories of brain cancers: primary cancers, which originate in the brain, and metastatic cancers, which originate elsewhere in the body and spread to the brain. Primary brain cancers may affect people of all ages, although they occur most frequently in children and older adults (ABTA 2014a). This protocol focuses on primary brain cancers and glioblastoma in particular.
Primary brain cancers are usually named after the type of brain cells from which the tumor arises (ABTA 2014b). Gliomas are tumors formed from glial cells (NCI 2018). Glial cells provide support and nutrition to neurons, the cells that transmit signals in the brain (ABTA 2014b). Primary brain tumors are given a tumor grade based on how normal the tumor cells look when viewed under a microscope (NCI 2018; NCCN 2016). The tumor grade provides some information on how quickly a tumor is likely to grow and spread to other tissues. Grade I tumor cells largely resemble normal cells and are referred to as “well-differentiated.” Glioblastoma is a grade IV glioma. The tumor cells do not look like normal cells and are referred to as “undifferentiated.” Glioblastomas tend to grow rapidly and spread into neighboring brain tissues faster than lower-grade tumors. Unlike many other types of grade IV cancers, however, glioblastoma does not usually spread to other organs outside the central nervous system (brain and spinal cord) (Costa 2017; Wu 2017; Seo 2012).Glioblastoma accounts for roughly 16% of all primary brain and central nervous system tumors and about half of all gliomas (Ostrom 2014; Ostrom 2018; Thakkar 2014). There were about 12,400 new glioblastoma cases in the United States in 2017 (ABTA 2014a).