Tell me about types of glioblastoma
Glioblastoma, also known as glioblastoma multiforme (GBM), is the most common and aggressive type of malignant brain tumor. It develops in the glial cells, which are supportive cells that surround and protect nerve cells in the brain. Glioblastoma is a serious and life-threatening condition, with a five-year survival rate of only about 5%. In this article, we will discuss the different types of glioblastoma and their characteristics.
1. Primary vs Secondary Glioblastoma
There are two main types of glioblastoma: primary and secondary. Primary glioblastoma develops spontaneously in the brain, meaning it has no known cause. It is the most common type, accounting for about 90% of all glioblastoma cases. On the other hand, secondary glioblastoma develops from lower-grade brain tumors, such as astrocytomas or oligodendrogliomas. This type usually affects younger patients and has a better prognosis compared to primary glioblastoma.
2. Classical vs Proneural vs Mesenchymal
Glioblastoma can also be classified into three subtypes based on their genetic profile: classical, proneural, and mesenchymal. Classical glioblastoma is characterized by mutations in the epidermal growth factor receptor (EGFR) gene, which promotes the growth and division of cancer cells. This subtype is associated with a shorter survival time and tends to be resistant to chemotherapy.
The proneural subtype is defined by mutations in the isocitrate dehydrogenase (IDH) gene, which plays a role in cell metabolism. Patients with this subtype are generally younger and have a better response to treatment compared to other subtypes. However, they may have a higher risk of tumor recurrence.
The mesenchymal subtype is characterized by mutations in the tumor suppressor gene p53, which regulates cell growth and division. This subtype is associated with a worse prognosis and a higher likelihood of tumor recurrence.
3. Giant Cell Glioblastoma
Giant cell glioblastoma is a rare form of glioblastoma that makes up less than 1% of all cases. It is characterized by the presence of giant cells, which are abnormally large cells with multiple nuclei. This type is more responsive to treatment and has a slightly better prognosis compared to other types of glioblastoma.
4. Gliosarcoma
Gliosarcoma is a type of glioblastoma that contains both glial cells and sarcoma cells, which are cancerous cells that originate from connective tissue. This type is also rare, accounting for only about 2% of all glioblastoma cases. It is more common in older adults and has a poorer prognosis compared to other types of glioblastoma.
5. Pediatric Glioblastoma
Although glioblastoma is typically seen in adults, it can also occur in children. Pediatric glioblastoma is more commonly found in the cerebral hemispheres of the brain, while adult glioblastoma is more commonly found in the frontal lobe. This type of glioblastoma has a similar genetic profile to adult glioblastoma but tends to have a better response to treatment and a slightly better prognosis.
In conclusion, glioblastoma is not a single type of brain tumor, but rather a group of tumors with varying characteristics and subtypes. Understanding the different types of glioblastoma is essential for proper diagnosis and treatment planning. Researchers continue to study these subtypes to develop more effective treatments and improve outcomes for patients with this aggressive form of brain cancer. If you or a loved one have been diagnosed with glioblastoma, it is important to work closely with a team of experienced healthcare professionals to determine the best treatment approach for your specific type of glioblastoma.
