Diseases and Disorders

Glioblastoma Brain Tumors

Lindsay Roberts


Abstract

Glioblastomas (GBMs) are one of the deadliest and most common brain tumors. GBMs are included in the class of glioma tumors, since they arise from the glial tissues of the brain. The purpose of this glue-like glial tissue is to keep the brain’s neurons in place, as well as to maintain the proper functioning of the neurons. Although various types of glia are capable of producing tumors, GBMs arise primarily from the star-shaped glial cells known as astrocytes, which support nerve cells. The tumours usually also include cystic minerals, blood vessels, and/or calcium deposits. Generally, these astrocytic GBMs can develop throughout the central nervous system. These aggressive tumors are typically found in the cerebral hemispheres. Contained within the hemispheres are both the centres for speech production and motor control, so the presence of a tumor poses great concern. A vast quantity of malignant tumor cells reproduce continuously, thriving off of an easily accessible bloody supply. There are two types of glioblastomas: primary and secondary. Primary GBMs are extremely aggressive and proliferate rapidly. Although secondary GBMs have a slower growth period and only represent 10% of all glioblastomas, they are still relatively aggressive. Symptoms resulting from glioblastomas can vary between patients. The most common indications are headaches caused by an increase in intracranial pressure from the GBMs’ rapid growth. Seizures, loss of balance, and alterations in speech and cognition may also be present [6].

 

Diagnosis and Treatment

     Different scans are taken using MRIs, CAT scans, and CTs. If a brain tumor is discovered in a scan, a neurosurgeon then gathers tumor tissue through a biopsy. Next, a neuropathologist analyzes the specifics to classify the tumor.Surgery is often the first option following a diagnosis of glioblastoma, although not all GBMs are operable. Due to the tumor’s invasiveness, it is impossible to fully remove a glioblastoma without risking damage to surrounding tissue. However, if surgeons are able to remove a large portion of the tumor, the patient's life expectancy is usually prolonged. Following surgery, the goal of radiation or chemotherapy is to attack the remaining tumor cells and slow malignant cell growth.

Figure 1: Above is a photo of a preserved brain affected by a highly invasive glioblastoma.

 

Risk Factors

     Although there is not one particular cause of GBMs, there are certain factors which could increase the likelihood of this abnormal cell reproduction in the brain. For instance, age as well as exposure to ionizing radiation may increase the risk of developing a brain tumor. Genetics may also be an important factor; in fact, a family history of gliomas doubles one’s risk of developing a tumor. Gliomas generally occur in adults between 60 and 80 years old. Specifically regarding glioblastomas, only 3% develop during childhood, while approximately 15.4% develop during adulthood. As one of the most fatal brain tumors, glioblastomas are classified as grade IV tumors. This classification of tumors is characterized as being both aggressive and malignant. Currently, researchers have discovered four separate “subtypes” of glioblastomas, which all respond differently to advanced treatments. Generally, treatment must use multiple approaches, since not all cells in a GBM can be targeted at once. Due to the wide variety of cells within a GBM, some cells may respond well to certain therapies, while others may not be affected at all. Therefore, patients diagnosed with glioblastomas are given a prognosis known as a “median survival” [2]. The median rate of survival is approximately 15 months for patients with aggressive GBMs, while patients with less severe cases can live up to three years with proper treatment. Unfortunately, up to this point, no treatment has been discovered that can completely cure this aggressive type of cancer. However, scientists continue to search for treatments that can slow the progress of glioblastomas and extend both years and quality of life.


References


  1. Abdelzaher, Eman. "Glioblastoma Multiforme." CNS Tumor - Glioblastoma Multiforme. N.p., n.d. Web. 22 May 2017.

  2. "Brain Tumor Symptoms." Brain Tumor Symptoms | MD Anderson Cancer Center. N.p., n.d. Web. 10 May 2017.

  3. "Glioblastoma Multiforme." AANS. N.p., n.d. Web. 10 May 2017.

  4. "Glioma." Mayo Clinic. Mayo Foundation for Medical Education and Research, 29 June 2016. Web. 10 May 2017.

  5. Center, Spotsylvania Regional Medical. "What Is the Cerebral Hemisphere? - Parts of the Nervous System." Sharecare. N.p., n.d. Web. 10 May 2017.

  6. "Glioblastoma (GBM)." Glioblastoma (GBM) | American Brain Tumor Association. N.p., n.d. Web. 10 May 2017.

  7. "Tumor Types." National Brain Tumor Society. N.p., n.d. Web. 10 May 2017.

Lindsay Roberts

Lindsay Roberts


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