Gliomas

What is Gliomas?

Glioma is the most frequent type of tumor in the central nervous system (your brain and spinal cord) that comes from glial cells, which support and protect the neurons in your brain. In America, six out of every 100,000 people are diagnosed with gliomas each year. These tumors can spread into other areas of the brain tissue, affecting its function. Amongst gliomas, glioblastoma is the most harmful type, and pilocytic astrocytoma is the least dangerous.

In the past, these spread-out gliomas were sorted into different types and levels based on their physical characteristics, for example, diffuse astrocytoma, oligodendrogliomas, or mixed gliomas/oligoastrocytomas. Recently, these gliomas were categorized according to marks on the genes and cells. This progress gives a better understanding of the person’s prognosis (what’s likely to happen) and also helps decide the best treatment method. Besides these genetic markers, gliomas are also grouped from grade I to IV, based on how fast the tumor cells are growing and whether there’s any dead tissue.

What Causes Gliomas?

Gliomas, a type of brain tumor, can be split into three categories based on the type of cell they resemble: astrocytomas, ependymomas, and oligodendrogliomas. These can be grouped as low-grade, atypical, or high-grade based on how the cells look, their activity, and the markers they have on a molecular level. The World Health Organization (WHO) uses these molecular markers to provide a rating for the tumor, which can give clues as to the patient’s outlook and potential treatment routes.

Astrocytomas stem from astrocyte cells. Some of these tumors are encased and have clear boundaries with normal cells, but others can infiltrate surrounding areas, indicating advanced stages. Lower grades are often seen in children, while higher grades are more common in adults and older people.

Oligodendrogliomas start from oligodendrocyte cells. These tumors tend to spread less than astrocytomas and usually arise in adults.

Ependymomas originate from ependymal cells. These are cells located in the areas lining the fluid-filled areas in the brain (the ventricular cavities) and the center of the spinal cord. Ependymomas generally occur in young patients.

Risk Factors and Frequency for Gliomas

Every year in the United States, around 80,000 new cases of primary brain tumors are diagnosed. Of these, about 20,000 – a quarter – are gliomas. Glioblastomas account for around 12,000 cases a year, which is roughly 15% of the total new brain tumor diagnoses.

Signs and Symptoms of Gliomas

Brain gliomas are a type of brain tumor. Their most common symptoms include headaches, nausea, vomiting, and seizures. In more advanced cases, they may cause weakness or changes in mental functioning. The physical examination of patients with gliomas may appear normal or show varying degrees of physical weakness, sensory issues, or mental changes. These are often due to the pressure effects of the tumor swelling.

• Headaches
• Nausea
• Vomiting
• Seizures
• Weakness (in advanced cases)
• Altered mental status (in advanced cases)
• Physical weakness, sensory issues, or mental changes due to the tumor’s pressure effects

Testing for Gliomas

If your doctor thinks you might have a brain tumor based on your medical history and physical examination, they will likely recommend several tests to confirm the diagnosis.

One of these tests is a Computed Tomography (CT) scan of your head. This is a type of X-ray which provides detailed images of the brain. It’s useful for identifying immediate issues, like internal bleeding, swelling, or unevenness in your brain tissue.

Another test you might have is a Magnetic Resonance Imaging (MRI) scan. This scan uses magnetic fields and radio waves to produce detailed images of the brain. It’s particularly sensitive and helps to identify the characteristics of brain tumors. For example, lower-grade (less dangerous) tumors usually don’t light up (‘enhance’) on an MRI scan, whereas higher-grade (more dangerous) tumors often do. In addition, the MRI scan will help your doctors determine how swollen your brain is. The results from this scan will be used to develop your treatment plan, which might involve surgery, radiation therapy, or chemotherapy.

If you’re recently diagnosed with a brain tumor, your doctor will also need to do a ‘metastatic workup’. This is a series of tests to check if cancer has spread from its original location to other parts of your body. For example, if you have a history of heavy smoking, you might need to have a chest X-ray. If an unusual mass is found on this X-ray, further investigation will be required using a CT scan of your body or a Positron Emission Tomography (PET) scan. These tests can help the doctor identify where the brain tumor may have originated from, if it’s not primary (meaning it started in the brain).

Treatment Options for Gliomas

The World Health Organization (WHO) has a classification system for a type of brain tumor known as gliomas. This system helps doctors figure out the best treatment plan for patients. Most of the time, this involves some form of surgery, either to completely remove the tumor or to take a sample for further testing.

There are different grades of gliomas according to the WHO classification, ranging from Grade I to Grade IV. Here’s a brief overview of some common types:

• Diffuse astrocytoma and anaplastic astrocytoma, some of which have a genetic mutation called IDH
• Glioblastoma, a particularly aggressive type that can be IDH wild-type (without the IDH mutation)
• Oligodendroglioma, another type that can be IDH-mutant and 1p/19q-co-deleted (having specific genetic changes)
• Several other types like pilocytic astrocytoma, subependymal giant cell astrocytoma, and pleomorphic xanthoastrocytoma
• Ependymal tumors like subependymoma, myxopapillary ependymoma, and anaplastic ependymoma
• Other various types of gliomas

When it comes to treating gliomas, the strategies can vary depending on their grade:

• Grade I gliomas can often be cured through surgery.
• For Grade II gliomas, performing a safe total removal of the tumor followed by routine checkups is currently considered good practice.
• Grade III gliomas and Grade IV gliomas (also known as glioblastomas) can be managed with a safe total removal of the tumor, radiation and chemotherapy, and close monitoring for tumor recurrence.

Certain protocols combining radiotherapy and chemotherapy, like the Stupp protocol, are often used for Grade III to Grade IV gliomas. Temozolomide, a type of chemotherapy, is typically given as part of this protocol.

If a glioma comes back after initial treatment, there are several options that can be considered. These may include further surgery, placing medication wafers at the tumor site, and targeted therapies such as drugs that stop the growth of new blood vessels (angiogenesis inhibitors) or boost the body’s immune response against the tumor (immunotherapy).

Patients with high-grade gliomas must also be managed for related symptoms and risks. They may be prone to seizures and complications due to fluid buildup (edema) in the brain or trouble moving. To manage these issues, medications to control seizures, prevent blood clots in deep veins (DVT prophylaxis), and reduce inflammation and swelling (steroids) may be used.

What else can Gliomas be?

When trying to make a diagnosis, a doctor might consider several possible conditions. These could include:

• Abscess (an area filled with pus)
• Demyelination (damage to the protective covering of nerve fibers)
• Gliosis (an abnormal increase of glial cells in areas of nerve damage)
• Infarct (an area of dead tissue caused by a lack of blood supply)
• Metastasis (spread of cancer from its primary location to other parts of the body)

What to expect with Gliomas

The likelihood of recovery from gliomas, a type of brain tumor, hinges on several factors. These include:

* The patient’s age
* Other health conditions the patient may have (comorbidities)
* The grade (severity) and location of the tumor
* If there is an accumulation of fluid in the brain (hydrocephalus)
* How well the person responds to supplementary treatment (adjuvant therapy)
* How much of the tumor can be removed through surgery.

Possible Complications When Diagnosed with Gliomas

• Raised pressure inside the skull
• Seizures or uncontrollable shaking
• Hydrocephalus, which is a buildup of fluid in the brain
• Brain herniation, where part of the brain is pushed out of its normal position
• Bleeding into the tumor
• Local spread, where the tumor grows into nearby areas
• Spinal metastases or the spreading of the tumor to the spine
• Potential death

Preventing Gliomas

It’s important for patients to understand the need for regular check-ups, taking their medicine as scheduled, and knowing any limitations on driving. Regular visits to the doctor can help monitor their health condition. Taking medication on time can ensure its effectiveness. Being aware of driving restrictions can ensure safety for themselves and others.