Gliomas are brain tumours that develop from glial cells. Neurons in the brain are supported and protected by these cells. Gliomas come in a variety of shapes and sizes.
Gliomas are the most common form of adult brain tumour, accounting for roughly 78 percent of all cancerous brain tumours.
Astrocytomas and ependymomas are two types of gliomas.
This article will describe what a glioma is and what a person with a glioma diagnosis can expect. Glioma varieties, risk factors, and treatment options will also be discussed.
What is it?
A glioma is a type of brain tumour that begins in the glial cells and grows from there.
Glial cells keep neurones in place and enable them to function properly by protecting and supporting them. They supply oxygen and nutrients to nerve cells while also removing dead cells from the brain.
Gliomas aren’t all cancerous. Cells do not always reproduce and disperse.
Gliomas of different grades spread at different rates. Low-grade gliomas spread slowly, while high-grade gliomas spread quickly.
Types
Gliomas are classified into three categories.
Astrocytomas
Atrocytes, which are star-shaped glial cells, are responsible for the growth of certain brain tumours. These tumours are astrocytomas.
Pilocytic astrocytomas are grade I astrocytomas. They have well-defined boundaries and a sluggish growth rate.
Grade II astrocytomas are also known as diffuse astrocytomas or low-grade astrocytomas. They have a slow growth rate and no well established boundaries. They are popular in people between the ages of 20 and 50.
Anaplastic astrocytomas are also known as grade III astrocytomas. They make up 2% of all brain tumours and develop more quickly and rapidly than lower-grade tumours. They often develop into the tissue around them.
Glioblastomas, or GBMs, are grade IV astrocytomas. They are the most aggressive type of glioma. This is the most common form of adult high-grade brain tumour. GBMs make up 12–15 percent of all brain tumours and have a 5-year survival rate of around 4%.
Ependymomas
Ependymomas are brain tumours that arise from ependymal cells. They are uncommon in adults, accounting for just 2–3% of all primary brain tumours.
Subependymomas and myxopapillary ependymomas are two types of grade I ependymomas that develop slowly.
The most common form of ependymal tumour is grade II, which is also known as ependymomas. They may be classified as cellular, papillary, clear cell, or tancytic ependymomas by physicians.
Anaplastic ependymomas are grade III ependymomas, which are faster-growing tumours.
Oligodendrogliomas
Oligodendrogliomas are brain tumours that arise from oligodendrocytes.
Low-grade oligodendrogliomas are Grade II, and high-grade oligodendrogliomas are Grade III or anaplastic oligodendrogliomas.
Symptoms
- seizures
- nausea and vomiting
- memory issues
- change in activity levels
- personality changes
- loss of appetite
- weakness
- difficulty balancing
- trouble walking
- worsening vision
- speech problems
Outlook
A person’s prognosis for glioma is determined by a variety of factors. For example, a person’s prognosis can vary based on the type of glioma they have or their age.
Depending on a person’s age, the American Cancer Society reports the following five-year survival rates for various forms of glioma:
| Tumor type | Age 20–44 | Age 45–54 | Age 55–64 |
|---|---|---|---|
| Low-grade (diffuse) astrocytoma | 73% | 46% | 26% |
| Anaplastic astrocytoma | 58% | 29% | 15% |
| Glioblastoma | 22% | 9% | 6% |
| Oligodendroglioma | 90% | 82% | 69% |
| Anaplastic oligodendroglioma | 76% | 67% | 45% |
| Ependymoma/anaplastic ependymoma | 92% | 90% | 87% |
Risk factors
Things that raise a person’s chances of developing an illness or disease are known as risk factors.
The majority of brain tumours, on the other hand, have no clear cause. They have no ties to something that could have been avoided by a human.
Hereditary factors
Some genetic disorders can increase the risk of developing malignant brain tumours. The following are examples of genetic disorders:
- neurofibromatosis type 1
- neurofibromatosis type 2
- von Hippel-Lindau syndrome
- Li-Fraumeni syndrome
Just about 5% of people with brain tumours have either of the above genetic disorders.
Environmental determinants
Certain substances that a person can come into contact with at work can cause cancer.
Vinyl chloride, for example, can increase a person’s risk of developing glioma. However, no direct correlation has been discovered by researchers.
Diagnosis
A healthcare practitioner may evaluate a person’s medical history and conduct a neurological exam if they exhibit signs or symptoms that could be related to a glioma.
To diagnose glioma, a doctor may use imaging scans or a biopsy.
The following imaging scans can be used to help a doctor decide whether a tumour is present:
The type of cells that make up the tumour cannot be determined by these scans. A biopsy may be recommended in this situation.
Treatment
Doctors aim to eliminate as much of the tumour as possible to keep it from recurring when treating brain tumours. They must also take great care not to damage the brain’s safe areas.
There are five forms of standard care, according to the National Cancer Institute:
- active surveillance
- surgery
- radiation therapy
- chemotherapy
- targeted therapy
Active surveillance
Regular checkups are needed to insure that a person’s condition does not deteriorate. They are not given any medication.
Active monitoring may be beneficial for people who have slow-growing tumours that aren’t causing any symptoms.
At this stage, the risks or possible side effects of treatment may outweigh the benefits, so doctors may decide to monitor the patient’s condition for a while before proceeding with treatment.
Surgery
Glioma may be treated with surgery as a first move. Depending on the tumor’s grade, a surgeon can be able to successfully extract the entire tumour or a significant amount of cancerous tissue.
It may not be necessary to remove the entire tumour depending on its location in the brain and the functions it affects.
Partially removing the tumour can help to reduce brain swelling and relieve some of the symptoms.
Radiation therapy
External beam radiation therapy, or EBRT, is a form of treatment for gliomas that doctors use.
High-energy rays (such as X-rays, photons, or protons) are sent into a person’s body and to the tumour by a massive machine.
Chemotherapy
Chemotherapy is a treatment that uses drugs to prevent cancer cells from developing.
Once drugs enter the bloodstream and circulate across the body, it is referred to as systemic chemotherapy. To target gliomas, a subset of chemotherapy drugs may cross the blood-brain barrier.
Doctors may suggest using a dissolvable wafer to position directly in the brain at the tumour site after the tumour has been removed for brain tumours.
Localized chemotherapy is the name for this procedure. It aids in the targeting of any residual tumours and can help to prevent unintended side effects in other areas of the body.
Targeted therapy
Cancer cells require specific molecules to develop and survive, and targeted therapies directly target those molecules.
One such treatment is bevacizumab, which is recommended by the National Comprehensive Cancer Network. This medication slows the growth of cancer cells by depriving them of the blood supply they need to survive.
Conclusion
The prognosis for a glioma is determined by a variety of factors. To find out the prognosis for their particular case, a person can contact their doctor.
If anyone thinks they have a glioma, they should see their doctor right away to confirm or rule it out.
Sources
- Adult central nervous system tumors treatment (PDQ®) – patient version. (2020).
https://www.cancer.gov/types/brain/patient/adult-brain-treatment-pdq - Are all gliomas malignant? (n.d.).
https://moffitt.org/cancers/brain-cancer/faqs/are-all-gliomas-malignant/ - Everything to know about glioma. https://www.medicalnewstoday.com/articles/glioma
- Astrocytoma brain tumor: Grade I – IV. (n.d.).
https://braintumor.org/brain-tumor-information/astrocytoma/ - Brain cancer. (n.d.).
https://www.cancerquest.org/patients/cancer-type/brain-cancer - Brain cancer – gliomas. (2016).
https://www.nccn.org/patients/guidelines/content/PDF/brain-gliomas-patient.pdf - Brain tumors. (n.d.).
https://www.aans.org/en/Patients/Neurosurgical-Conditions-and-Treatments/Brain-Tumors - Carcinogen list. (2012).
https://www.cdc.gov/niosh/topics/cancer/npotocca.html - Ependymoma. (n.d.).
https://www.abta.org/tumor_types/ependymoma/ - Glioblastoma and malignant astrocytoma. (n.d.).
https://www.abta.org/wp-content/uploads/2018/03/glioblastoma-brochure.pdf - Oligodendroglioma. (n.d.).
https://www.abta.org/tumor_types/oligodendroglioma/ - Survival rates for selected adult brain and spinal cord tumors. (2020).
https://www.cancer.org/cancer/brain-spinal-cord-tumors-adults/detection-diagnosis-staging/survival-rates.html