Gliomas are a large group of brain and spinal cord tumors that originate from glial cells, a major brain cell that can develop into cancer. Symptoms, prognosis and treatment of malignant gliomas are determined by the patient’s age, tumor type and location of the tumor in the brain. These tumors tend to grow or invade into normal brain tissue, complicating treatment and making surgical removal difficult or even impossible. The risk of brain tumors increases with age, reaching a maximum risk around the ages of 75-84. Hypofractionated gliomas usually occur in children, while brain tumors are slightly more prevalent in men. The only risk factor for malignant glioma is prior radiation exposure to the brain, and family history factors account for less than 5% of the risk for this type of tumor, which is exacerbated by some genetic disorders in pediatric patients but less so in adults. There is no definite relationship between the development of malignant glioma and alcohol consumption, smoking and cell phone use.
There are different types of gliomas. Forty-two percent of brain tumors are benign, and 77% of malignant brain tumors are gliomas. Gliomas are named based on a specific type of glial cell in brain cells. According to the American Oncological Society, there are three types of gliomas, including astrocytoma, oligodendroglioma, and ventricular meningeal cell tumor.
Astrocytomas —- account for 35% of brain tumors and originate from astrocytes. The majority of these tumors cannot be cured because they spread through normal brain tissue. Astrocytomas are classified as low-grade malignant, moderately malignant, and highly malignant tumors based on pathology in microscopic histological sections. Glioblastoma, one of the most common malignant brain tumors in adults, grows very rapidly.
Oligodendrocytoma —- accounts for 4% of all brain tumors, it spreads in a similar manner to astrocytoma and is usually not curable by surgery.
Ventricular meningioma —- accounts for 2% of all brain tumors. This tumor is derived from ventricular meningeal cells, and because it does not spread into normal brain tissue, some ventricular meningiomas can be cured surgically.
What are the symptoms of glioma?
The symptoms of glioma are similar to those of other malignant tumors of the brain, depending on the location of the brain tissue it has attacked. One of the most common symptoms is headache – about half of the patients with brain tumors have clinical manifestations of headache. Other common symptoms include seizures, memory loss, physical weakness, difficulty controlling limbs, visual symptoms, speech problems, cognitive impairment, and personality changes. Different parts of the brain are affected and produce different symptoms.
As the tumor continues to grow and brain cells continue to be destroyed, some brain tissue is compressed and these symptoms may change or become more severe, causing edema in the brain and pressure on the skull.
How is a glioma diagnosed?
If your doctor suspects that you have a brain tumor, or if you have persistent headaches and severe symptoms (such as seizures), you will need a cranial scan. If the scan of the skull suggests a cranial tumor, a pathological biopsy will be used to diagnose a malignant glioma, either alone or during surgical removal of the brain tumor.
3. How is glioma graded?
Gliomas are classified into various subtypes according to their different characteristics. Grade I tumors are slow growing and can usually be removed surgically, while grade IV tumors are fast growing, aggressive and difficult to treat.
According to the World Health Organization (WHO) literature in 2000, the widely used grading of malignant gliomas is as follows.
Grade I glioma, also known as astrocytoma multiforme is commonly seen in children.
Grade II gliomas are low-grade fibrous astrocytic gliomas.
Grade III gliomas are called undifferentiated astrocytic gliomas and they are usually considered to be highly malignant.
Grade IV refers to malignant gliomas, which means glioblastoma multiforme (GBM). At least 80% of malignant gliomas are glioblastoma multiforme and are considered highly malignant.
Oligodendroglioblastoma tumors are graded as follows.
Grade 2 or low-grade malignant oligodendroglioma
Grade 3 or highly malignant oligodendroglial cell tumor
Ventricular meningeal tumors are classified as ventricular meningiomas and mesenchymal ventricular meningiomas (which are more aggressive).
Less malignant tumors are usually slow growing, but may change to more malignant tumors over time.
How are gliomas treated?
Depending on the location of the tumor, histological classification, and malignancy, there are different treatments available for malignant gliomas. The patient’s age and physical condition also influence the treatment plan. The treatment of gliomas is varied and can be summarized as follows.
Surgical removal of the tumor is the primary treatment if the patient has relatively good function of other organs and if the speech and behavioral functions of the brain are intact. Imaging techniques such as PET scans and functional MRI scans can help to preserve the function of the resected tumor intraoperatively. The goal of surgical treatment is to remove as much of the tumor as possible. Recurrence of the tumor is very common.
Radiotherapy is the use of high energy X-rays or other radiation to kill tumor cells.
Chemotherapy is the use of drugs to stop the growth of tumor cells, which can be injected or given orally.
Supportive therapy is used to improve clinical symptoms or improve neurological function. Corticosteroids are used to relieve headache or neurological symptoms by reducing tumor-induced brain edema, and antiepileptic drugs are used to control or prevent epilepsy.
1. Treatment of low-grade malignant astrocytoma
According to the American Cancer Society, surgery is the treatment of choice for low-grade malignant astrocytomas (if feasible), because these tumors grow deep in the brain and become entangled with normal brain tissue, making surgery sometimes difficult.
2. Treatment of highly malignant astrocytomas
Highly malignant astrocytomas (grade III mesenchymal astrocytoma or grade IV glioblastoma multiforme) can still be considered for surgical treatment if feasible, although surgery is no longer curative at this point. After surgery, the next step is radiation therapy, combined with chemotherapy. In some cases, surgery is no longer possible to remove the malignant tumor, and the surgeon will simply use radiation therapy plus chemotherapy. If the tumor regresses or shrinks, surgery plus other chemotherapy regimens may be reconsidered.
3.Treatment of oligodendroglioma
For oligodendroglioma, surgery is the treatment of choice. Although not curable, surgery will help relieve symptoms and increase survival. Chemotherapy and/or radiation therapy may be given after surgery, and again, chemotherapy or radiation therapy may help reduce the size of the tumor before surgery. If surgery is not possible, treatment with chemotherapy or a combination of radiation therapy is usually used.
4. Treatment of ventricular meningioma and mesenchymal ventricular meningioma
Ventricular meningioma and mesenchymal ventricular meningioma are different from other gliomas in that they do not grow intertwined with normal brain tissue and can be surgically cured if the tumor can be completely removed. Sometimes surgery cannot completely remove the tumor and chemotherapy or radiation therapy should be added after surgery.
V. What is the prognosis of glioma?
Highly malignant gliomas grow very rapidly, they are incurable, and the prognosis is usually poor, especially for older patients with brain tumors. In the rare cases of mesenchymal astrocytoma (grade IV glioma), survival can be extended to as long as 3 years with conventional treatment. However, with the advent of new targeted therapies, drugs, gene therapy, and some experimental medical treatments aimed at boosting the patient’s own immune system, more patients with glioma will be able to receive effective treatment.
The symptoms, prognosis and treatment of malignant gliomas are determined by the patient’s age, tumor type and location in the brain. These tumors tend to grow or invade normal brain tissue, complicating treatment and making surgical removal difficult or impossible. The risk of brain tumors increases with age, reaching a maximum risk around the ages of 75-84. Hypofractionated gliomas usually occur in children, while brain tumors are slightly more prevalent in men. The only risk factor for malignant glioma is prior radiation exposure to the brain, and family history factors account for less than 5% of the risk for this type of tumor, which is exacerbated by some genetic disorders in pediatric patients but less so in adults. There is no definite relationship between the development of malignant glioma and alcohol consumption, smoking and cell phone use.
There are different types of gliomas. Forty-two percent of brain tumors are benign, and 77% of malignant brain tumors are gliomas. Gliomas are named based on a specific type of glial cell in brain cells. According to the American Oncological Society, there are three types of gliomas, including astrocytoma, oligodendroglioma, and ventricular meningeal cell tumor.
Astrocytomas —- account for 35% of brain tumors and originate from astrocytes. The majority of these tumors cannot be cured because they spread through normal brain tissue. Astrocytomas are classified as low-grade malignant, moderately malignant, and highly malignant tumors based on pathology in microscopic histological sections. Glioblastoma, one of the most common malignant brain tumors in adults, grows very rapidly.
Oligodendrocytoma —- accounts for 4% of all brain tumors, it spreads in a similar manner to astrocytoma and is usually not curable by surgery.
Ventricular meningioma —- accounts for 2% of all brain tumors. This tumor is derived from ventricular meningeal cells, and because it does not spread to normal brain tissue, some ventricular meningiomas can be cured surgically, and this tumor rarely spreads outside the brain.
What are the symptoms of glioma?
Symptoms of glioma are similar to those of other malignant tumors of the brain, depending on the location of the brain tissue it has attacked. One of the most common symptoms is headache – about half of the patients with brain tumors have clinical manifestations of headache. Other common symptoms include seizures, memory loss, physical weakness, difficulty controlling limbs, visual symptoms, speech problems, cognitive impairment, and personality changes. Different parts of the brain are affected and produce different symptoms.
As the tumor continues to grow and brain cells continue to be destroyed, some brain tissue is compressed and these symptoms may change or become more severe, causing edema in the brain and pressure on the skull.
How is a glioma diagnosed?
If your doctor suspects that you have a brain tumor, or if you have persistent headaches and severe symptoms (such as seizures), you will need a cranial scan. A cranial scan includes a CT or MRI. If the cranial scan suggests a cranial tumor, a pathology biopsy will be used to diagnose a malignant glioma, either alone or during surgical removal of the brain tumor.
How are gliomas graded?
Gliomas are classified into various subtypes according to their different characteristics. Grade I tumors are slow-growing and can usually be surgically removed, while grade IV tumors are rapidly growing, aggressive and difficult to treat.
According to the World Health Organization (WHO) literature in 2000, the widely used grading of malignant gliomas is as follows.
Grade I glioma, also known as astrocytoma multiforme is commonly seen in children.
Grade II gliomas are low-grade fibrous astrocytic gliomas.
Grade III gliomas are called undifferentiated astrocytic gliomas and they are usually considered to be highly malignant.
Grade IV refers to malignant gliomas, which means glioblastoma multiforme (GBM). At least 80% of malignant gliomas are glioblastoma multiforme and are considered highly malignant.
Oligodendroglioblastoma tumors are graded as follows.
Grade 2 or low-grade malignant oligodendroglioma
Grade 3 or highly malignant oligodendroglial cell tumor
Ventricular meningeal tumors are classified as ventricular meningiomas and mesenchymal ventricular meningiomas (which are more aggressive).
Less malignant tumors are usually slow-growing, but may change to more malignant tumors over time.
How are gliomas treated?
There are different treatment options for malignant gliomas depending on the location of the tumor, histologic staging, and the degree of malignancy. The age and physical status of the patient also influence the treatment plan. The treatment of gliomas is varied and can be summarized as follows.
Surgical removal of the tumor is the primary treatment if the patient has relatively good function of other organs and if the speech and behavioral functions of the brain are intact. Imaging techniques such as PET scans and functional MRI scans can help to preserve the function of the resected tumor intraoperatively. The goal of surgical treatment is to remove as much of the tumor as possible. Recurrence of the tumor is very common.
Radiotherapy is the use of high energy X-rays or other radiation to kill tumor cells.
Chemotherapy is the use of drugs to stop the growth of tumor cells, which can be injected or given orally.
Supportive therapy is used to improve clinical symptoms or improve neurological function. Corticosteroids are used to relieve headache or neurological symptoms by reducing tumor-induced brain edema, and antiepileptic drugs are used to control or prevent epilepsy.
1. Treatment of low-grade malignant astrocytoma
According to the American Cancer Society, surgery is the treatment of choice for low-grade malignant astrocytomas (if feasible), because these tumors grow deep in the brain and become entangled with normal brain tissue, making surgery sometimes difficult.
2. Treatment of highly malignant astrocytomas
Highly malignant astrocytomas (grade III mesenchymal astrocytoma or grade IV glioblastoma multiforme) can still be considered for surgical treatment if feasible, although surgery is no longer curative at this point. After surgery, the next step is radiation therapy, combined with chemotherapy. In some cases, surgery is no longer possible to remove the malignant tumor, and the surgeon will simply use radiation therapy plus chemotherapy. If the tumor regresses or shrinks, surgery plus other chemotherapy regimens may be reconsidered.
3.Treatment of oligodendroglioma
For oligodendroglioma, surgery is the treatment of choice. Although not curable, surgery will help relieve symptoms and increase survival. Chemotherapy and/or radiation therapy may be given after surgery, and again, chemotherapy or radiation therapy may help reduce the size of the tumor before surgery. If surgery is not possible, treatment with chemotherapy or a combination of radiation therapy is usually used.
4. Treatment of ventricular meningioma and mesenchymal ventricular meningioma
Ventricular meningioma and mesenchymal ventricular meningioma are different from other gliomas in that they do not grow intertwined with normal brain tissue and can be surgically cured if the tumor can be completely removed. Sometimes the tumor cannot be completely removed by surgery, and chemotherapy or additional radiation therapy should be given after surgery.
V. What is the prognosis of glioma?
The prognosis is usually poor, especially for elderly patients with brain tumors. According to the World Health Organization (WHO), the average survival time for patients with grade IV glioblastoma is about 12 months. In the rare cases of mesenchymal astrocytoma (grade IV glioma), survival can be extended to as long as 3 years with conventional treatment. However, with the advent of new targeted therapies, drugs, gene therapy, and some experimental medical treatments aimed at boosting the patient’s own immune system, more patients with glioma will be able to receive effective treatment.