What Is Oligodendroglioma?

Do you often get headaches and/or have you recently experienced seizures? While there could be many reasons behind this, there is a small chance that it could be an oligodendroglioma. This is unlikely, but checking in with your doctor and finding out the cause behind your symptoms might ensure that the problem is identified and resolved with the least impact on your health and well-being possible. 

Keep on reading if you want to find out more about this type of brain tumour, its causes, how it’s diagnosed and how it’s treated.

Overview

This article refers specifically to primary brain cancer or tumours that first arise in the brain. For information on tumours that have spread to the brain from elsewhere in the body, known as secondary brain cancer, please visit pages such as this one. 

Oligodendroglioma is a type of brain tumour.¹ Like other gliomas, oligodendroglioma develops from glial cells. While its cells resemble oligodendrocytes -  a type of glial cell that covers nerve cells with a substance to make nerve signals travel faster - it is unclear whether oligodendroglioma develops from these cells.² 

Oligodendroglial tumours usually develop in the brain’s frontal lobe but can (rarely) appear in other parts of the central nervous system like the spinal cord. While they can spread to other organs, this is also rare.³ 

Oligodendrogliomas normally present a single tumour with well-defined borders and might show signs of swelling. If it grows quickly, oligodendroglioma is known as an anaplastic oligodendroglioma. 

The third most common glial tumour, oligodendrogliomas make up around 5% of tumours affecting the central nervous system. It is estimated that four out of every million people develop the disease each year.^2,4

There is no known cause for oligodendrogliomas, though certain genetic characteristics are associated with the severity of the condition.³  

Causes of oligodendroglioma

Tumour cells arise when cells stop behaving as they should due to changes in their DNA.⁵ They may initially form benign tumours, but they can later become malignant and become cancerous. Genetic predispositions, exposure to chemicals and radiation, and habits such as diet and exercise can influence the likelihood of cancer.

Though we do not yet know the exact cause, oligodendrogliomas often show particular abnormalities in their DNA such as changes in a gene known as IDH or missing specific pieces of DNA on chromosomes 1p and 19q.⁶   This information is used to decide on the most effective treatment.

Signs and symptoms of oligodendroglioma

The symptoms of oligodendroglioma may vary depending on where in the brain it is found, though the most common symptoms are seizures (more than half of people experience one before diagnosis), headaches, difficulty thinking and remembering, issues with moving and keeping balance, and weakness.³ 

Please see a doctor if you have one or more of these symptoms. Though it is unlikely that oligodendroglioma is behind them, it is best to make sure and catch the tumour at an early stage if it is present.

Management and treatment for oligodendroglioma

If you have oligodendroglioma, surgery, radiation, and chemotherapy are the most often used therapies.¹  Treatments are decided based on your age, the type of tumour, its location, and how it responds to treatment (for example, how much of it remains after surgery).³  

If your tumour grows very slowly, it may not be possible to cure it. Even then, treatment can still shrink it and limit its growth, relieving some of your symptoms and making you feel better.⁷

Surgery

The usual first step in treating oligodendroglioma is removing it through surgery. This is called surgical resection. If it grows very slowly, closely monitoring the oligodendro- glioma through regular MRI scans might be sufficient. 

Oligodendrogliomas often grow into surrounding tissue, making it difficult to remove the tumour completely. Radiotherapy and/or chemotherapy may be used in an effort to eliminate any remaining tumour. If the oligodendroglioma cannot be surgically removed, a combination of radiation therapy and chemotherapy may be recommended.⁸ 

Surgery may be repeated if the tumour grows back (known as a recurrent tumour). 

Radiation therapy

Radiotherapy uses radiation to kill tumour cells. It is a recommended treatment option if:

• You have the “1p/19q” gene change
• You are 40 years old or older
• The tumour was only partially removed during surgery

Chemotherapy

Oligodendroglioma is treated with what is known as PCV chemotherapy. It consists of the drugs procarbazine, lomustine (CCNU) and vincristine. Compared to other brain tumours, oligodendrogliomas usually respond well to chemotherapy.⁸ Chemotherapy may replace radiotherapy if you are not feeling well after surgery. 

Other options

Depending on your overall response to previous treatment, clinical trials testing new forms of chemotherapy, targeted therapy (a treatment that specifically attacks tumour cells) or immunotherapy (a treatment that activates your immune system to attack the tumour) may be available to you as a treatment option.³ Speak with your doctor to find out if you are eligible for any clinical trials. 

After treatment

After recovering, you may be asked to come back for regular MRI scans to make sure everything is fine. How often you get checked will depend on the grade:

1. Low-grade oligodendroglioma: every 6 months for the first two years and every 1 or 2 years thereafter
2. High-grade oligodendroglioma: every 3 - 6 months for the first two years, and once every 6 months or every year thereafter

FAQs

How is oligodendroglioma diagnosed?

To diagnose oligodendroglioma, your doctor will first measure and locate the tumour to choose the best treatment option. The tests may include an MRI scan, a CT scan, a biopsy, a blood test, or a neurological exam.¹  

Can oligodendroglioma be prevented?

Currently, there is no known way to prevent oligodendroglioma, though maintaining a healthy lifestyle and reducing exposure to risk factors may decrease its likelihood. 

Who is at risk of oligodendroglioma?

There are no known risk factors specific to oligodendroglioma. Overall, the risk of cancer is influenced by genetics, exposure to certain chemicals and radiation, and lifestyle habits such as diet and physical exercise. 

How common is oligodendroglioma?

Oligodendroglioma is rare, with 4 cases per 1,000,000 people occurring each year. It is slightly more common in people that have been assigned male at birth (AMAB) and most often affects people between ages 35 and 44, though it may develop at any age.^2,4 

What are the stages of oligodendroglioma?

Stages are commonly used to define the severity of cancers. Tumours of the central nervous system, including the brain and spinal cord, are given grades based on where the tumour is, what type, how much it has spread to nearby tissue, its genetic characteristics, the age of the patient, and how much the tumour remains after surgery.³

Specifically, oligodendrogliomas are split into two grades:

• Grade II oligodendroglioma (also known as a low grade) - the tumour cells grow slowly and spread to nearby tissue. Since grade II oligodendrogliomas don’t cause symptoms immediately, it might take years to be diagnosed
• Grade III oligodendroglioma (also known as high grade or anaplastic) - the tumour grows quickly

When should I see a doctor?

If you experience symptoms such as seizures, headaches, or difficulty thinking and remembering, please see a doctor as soon as possible.. 

Summary

Oligodendroglioma is a rare type of brain tumour that can be highly disruptive if left untreated, with symptoms including seizures, headaches and problems thinking and moving.

It is important to be alert to any changes and signs of oligodendroglioma and to seek medical help if needed. This will lead to diagnosing oligodendroglioma as early as possible and increasing your chances of recovery and overall survival.

Being diagnosed with brain cancer can be a difficult experience. Please know that there is practical and emotional support available to those living with a brain tumour through dedicated institutions such as The Brain Tumour Charity, Brainstrust or Brain Tumour Support. You can find a list of organisations along with useful resources here.