Gliomas

A typical form of tumor with brain origins is the glioma. Gliomas, which include astrocytes, oligodendrocytes, and ependymal cells and surround and support neurons in the brain, account for about 33% of all brain cancers.

Gliomas are often called intra-axial brain tumors because they frequently merge with healthy brain tissue and develop within the substance of the brain.

Types of gliomas

Astrocytoma: The most frequent primary intra-axial brain tumor, accounting for approximately half of all primary brain tumors, astrocytomas are glial cell tumors derived from connective tissue cells termed astrocytes. The cerebrum (the vast, outer portion of the brain) and the cerebellum are where they are most frequently found (located at the base of the brain).

Adults and toddlers alike can develop astrocytomas. The most dangerous type of brain tumors are high-grade astrocytomas, often known as glioblastoma multiforme. The symptoms of glioblastoma are frequently the same as those of other gliomas. Low-grade cerebellar gliomas known as pilocytic astrocytomas are frequently detected in young patients. Astrocytomas in the cerebrum are more frequent in adulthood.

Brain stem gliomas: Rare tumors in the brain stem are referred to as diffuse infiltrating brainstem gliomas (DIPGs) or brain stem gliomas. Due to their remote position, where they interweave with healthy brain tissue and impair the delicate and complicated functions this area regulates, they are typically impossible to remove surgically. The majority of youth mortality from primary brain tumors is caused by these tumors, which most frequently affect school-age children.

Ependymomas: Ependymal cells that line the ventricles or the spinal cord give rise to ependymomas. Only 2 to 3 percent of initial brain tumors are ependymomas, which are extremely uncommon. They do, however, make up between 8% and 10% of pediatric brain tumors and are more likely to affect children under the age of 10. Near the cerebellum is where ependymomas most frequently occur in children. Here, the tumor may hinder the movement of the cerebral spinal fluid and raise intracranial pressure (obstructive hydrocephalus.) The movement of spinal fluid can cause these tumors to metastasize (drop-metastasize) to other regions of the brain or spinal cord.

Mixed Gliomas: Multiple glial cell types make up mixed gliomas, also known as oligo-astrocytomas. Genetic testing of tumor tissue may settle the debate over their classification as a specific tumor type. These tumors are most frequently discovered in adult men and are in the cerebrum.

Oligodendrogliomas: Oligodendrocytes, the brain’s supporting tissue cells, give rise to oligodendrogliomas, which are typically located in the cerebrum. Oligodendrogliomas make up between 2 and 4 percent of primary brain tumors. Young and middle-aged adults are the most likely to experience them, and men are more prone to do so. 50 to 80 percent of individuals who have these gliomas experience seizures, along with headaches, paralysis, or speech difficulties. In comparison to most other gliomas, oligodendrogliomas often have a better prognosis.

Optic pathway gliomas: Low-grade tumors known as “optic pathway gliomas” are frequently discovered in the chiasm or optic nerve, where they infiltrate the optic nerves that carry signals from the eyes to the brain. They are more prone to appear in those who have neurofibromatosis. Since these tumors are frequently found at the base of the brain, where hormonal regulation is located, optic nerve gliomas can result in visual loss and hormonal issues. Hypothalamic gliomas are gliomas that can disrupt hormone production.

Gliomas cause symptoms by pressing on the brain or spinal cord. The most common glioblastoma symptoms are:

• Headaches
• Seizures
• Personality changes
• Weakness in the arms, face or legs
• Numbness
• Problems with speech

Other symptoms include:

• Nausea and vomiting
• Vision loss
• Dizziness

Glioblastoma symptoms and other symptoms of glioma appear slowly and may be subtle at first. Some gliomas do not cause any symptoms and might be diagnosed when you see the doctor about something else.

Diagnosis of glioma involves:

• A medical history and physical exam: This includes questions about the patient’s symptoms and personal and family health history.
• A neurological exam: This exam tests vision, hearing, speech, strength, sensation, balance, coordination, reflexes, and the ability to think and remember.
• The doctor may examine your eyes to look for any swelling caused by pressure on your optic nerve, which connects the eyes to the brain. This swelling — papilledema — is a sign that requires immediate medical attention.
• Scans of the brain: Magnetic resonance imaging (MRI) and computed tomography (CT or CAT scan), which use computers to create detailed images of the brain, are the most common scans used to diagnose brain tumors.
• A biopsy: This is a procedure to remove a small sample of the tumor for examination under a microscope. Depending on the location of the tumor, the biopsy and removal of the tumor may be performed at the same time. If doctors cannot perform a biopsy, they will diagnose the brain tumor and determine a treatment plan based on other test results.

The grade of a glioma determines the course of treatment. Gliomas are most frequently referred to as “low grade” (classes I or II) or “high grade” (grades III or IV), depending on the tumor’s growth potential and aggressiveness. There are four grades of brain tumors.

The optimal course of action for each patient is determined by the location of the tumor, any potential side effects, and the potential advantages and disadvantages of the various treatment options (modalities).

Glioma treatment is individualized for each patient and may entail surgery, radiation therapy, chemotherapy, or just observation.

The most frequent initial therapy for gliomas is surgery, which calls for a craniotomy (opening of the skull). If the tumor is close to significant brain regions, intraoperative MRI or intraoperative brain mapping may be used.

A biopsy performed during surgery delivers tissue samples to the pathologist, who can then accurately diagnose the makeup and characteristics of the tumor so you can receive the optimal treatment.

To ease pressure on the brain, tumor tissue may also be removed during surgery. It could be a critical procedure.

Once the tumor’s identity or diagnosis has been established, radiation treatment and chemotherapy are frequently administered after surgery. Adjuvant therapies are what these procedures are known as.

Some glioma forms, or those in areas where surgery is risky, get radiation therapy after surgery. Gliomas are treated with one of three methods of radiation therapy:

• External beam radiation therapy
• Stereotactic radiosurgery
• Internal radiation

Chemotherapy, including wafers and targeted therapy, is recommended for some high-grade gliomas after surgery and radiation therapy.

• Systemic, or standard, chemotherapy
• Chemotherapy wafers (i.e., Gliadel®)
• Targeted therapy

To screen for tumor growth following treatment, brain scans—typically MRIs—may be carried out. The scans occasionally reveal regions that resemble recurrent tumors, but these are frequently dead tissue or alterations in healthy tissue brought on by radiation therapy, chemotherapy, or a combination of the two. To ascertain whether the glioma has returned, neurosurgeons and neuroradiologists will closely watch this. In that case, your neurosurgeon might suggest a different surgical method.

CAR T-Cell therapy for treatment of gliomas

A recently created immunotherapy for the treatment of tumors is called chimeric antigen receptor-engineered T-cell (CAR-T) therapy. Its usage in the treatment of solid tumors, such as gliomas, has been investigated because CAR-T cell therapy in China has demonstrated remarkable efficacy in the treatment of CD19-positive hematological malignancies.