Oligodendroglioma

Definition

Oligodendrogliomas are brain tumors arising from oligodendrocytes, a type of cell that makes up the supportive (glial) tissue of the brain.

Epidemiology

In the United States, a rare disease is defined as a condition that affects fewer than 200,000 people. This definition was created by Congress in the Orphan Drug Act of 1983. Other countries have their own official definitions of a rare disease. In Europe, a disease is defined as rare when it affects fewer than 1 in 2,000 people.

Grades

Primary CNS tumors are graded based on the tumor location, tumor type, extent of tumor spread, genetic findings, the patient’s age, and tumor remaining after surgery, if surgery is possible.

Oligodendrogliomas are grouped in two grades based on their characteristics.

• Grade II oligodendrogliomas are low grade tumors. This means the tumor cells grow slowly and invade nearby normal tissue. In many cases, they form years before being diagnosed as no symptoms appear.
• Grade III oligodendrogliomas are malignant (cancerous). This means they are fast-growing tumors. They are called anaplastic oligodendriogliomas.

Cause

• Cancer is a genetic disease – that is, cancer is caused by certain changes to genes that control the way our cells function.
• Genes may be mutated (changed) in many types of cancer, which can increase the growth and spread of cancer cells.
• The cause of most oligodendrogliomas is not known.
• Exposure to radiation and certain gene changes that can be passed down through families have been linked to a higher chance of developing oligodendrogliomas.

Signs and symptoms

Symptoms related to oligodendrogliomas depend on the tumor’s location. Here are some possible symptoms that can occur.

Oligodendroglioma Symptoms The most common sign of an oligodendroglioma is a seizure. Around 60% of people have a seizure before being diagnosed.

Other symptoms people may have:

• Headaches
• Problems with thinking and memory
• Weakness
• Numbness
• Problems with balance and movement

Diagnosis

• To get an accurate diagnosis, a piece of tumor tissue will be removed during surgery, if possible.
• A neuropathologist should then review the tumor tissue.

Treatment

• The first treatment for an oligodendroglioma is surgery, if possible.
• The goal of surgery is to obtain tissue to determine the tumor type and to remove as much tumor as possible without causing more symptoms for the person. Treatments after surgery may include radiation, chemotherapy, or clinical trials.
• Clinical trials, with new chemotherapy, targeted therapy, or immunotherapy drugs, may also be available and can be a possible treatment option. Treatments are decided by the patient’s healthcare team based on the patient’s age, remaining tumor after surgery, tumor type, and tumor location.
• Your oncologist might recommend a combination of medications - procarbazine, lomustine, and vincristine.
• A chemotherapy called temozolomide is also being studied in clinical trials.

Prognosis

The relative 5-year survival rate for oligodendroglioma is 74.1% but know that many factors can affect prognosis. This includes the tumor grade and type, traits of the cancer, the person’s age and health when diagnosed, and how they respond to treatment.

NIH genetic and rare disease info

• NIH info on Oligodendroglioma

Oligodendroglioma is a rare disease.

Oligodendroglioma Resources
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