Types of Brain & Spinal Cord Tumors
Brain and spinal cord tumors are named based on where they begin, and the main cell type they contain. Glial cells make up 90% of our brain cells, and they play a major role in how we think. There are many types of glial cells.
The World Health Organization (WHO) classifies brain tumors by their cell type, location, how they behave, and their molecular features. Some tumors are also given a grade based on how fast they grow and spread. Grades range from “grade I” (benign or the least aggressive), to “grade IV” (malignant and the most aggressive). Tumors graded in the I-II range are usually easier to treat and manage.
These tumors begin in brain cells called astrocytes (a type of glial cell), which help keep nerve cells healthy.
- Brain Stem Glioma Pilocytic Astrocytoma (grade I)
- Diffuse Astrocytoma (grade II)
- Anaplastic Astrocytoma (grade III)
- Glioblastoma (grade IV)
Astrocytomas are divided into two categories: those with and without isocitrate dehydrogenase (IDH) mutations. IDH mutations are more common and tend to grow more slowly.
These tumors begin in brain glial cells called oligodendrocytes.
- Oligodendroglioma (grade II)
- Anaplastic oligodendroglioma (grade III)
Oligodendrogliomas with IDH mutations tend to grow more slowly.
These tumors have both oligodendrocytes and astrocytes—and often start in in the cerebrum. With modern molecular testing (IDH mutations and 1p/19 codeletion), most of these tumors are found to be one type or the other. True oligoastrocytomas are very rare.
- Oligoastrocytoma (grade II)
- Anaplastic oligoastrocytoma (grade III)
These tumors begin in cells that line the fluid-filled spaces of the brain and spinal cord called the ependyma. Ependymal cells are a type of glial cell and ependymomas are considered a type of glioma.
- Ependymoma (grade I or II)
- Anaplastic ependymoma (grade III)
Pineal Parenchymal Tumors
These tumors form in the cells that make up most of the pineal gland (the gland that makes melatonin). These tumors are different from pineal astrocytic tumors.
- Pineocytomas (grade II)
- Pineoblastomas (grade IV)
This tumor forms in the meninges (thin layers of tissue that cover the brain and spinal cord). It can form from different types of brain or spinal cord cells. Most meningiomas are slow growing grade I tumors. Grade II and III meningiomas are more aggressive.
- A hemangiopericytoma/solitary fibrous tumor resemble meningiomas but are different biologically and treated like a grade II or III meningioma
Germ cell tumors usually form in the center of the brain, near the pineal gland. They can spread to other parts of the brain and spinal cord. These tumors impact the cells that develop into sperm in men or ova (eggs) in women. They can be either benign or malignant. Types include:
- Embryonal yolk sac carcinomas
This tumor begins in the center of the brain, just above the back of the nose. It can form from different types of brain or spinal cord cells.
- Pituitary Tumors
- Craniopharyngioma (grade I)
Symptoms are closely related to where the tumor forms and how it affects that part of the brain. The brain has three main sections:
- The cerebrum - The largest part of the brain, at the top of the head. It controls thinking, learning, problem solving, emotions, reading, writing, and voluntary movement. In many people, the left side of the brain controls speech.
- The cerebellum - The lower back of the brain, near the middle of the back of the head. It controls movement, balance, and posture.
- The brain stem - The lowest part of the brain (just above the back of the neck). The brain stem connects the brain to the spinal cord. It controls breathing, heart rate, and the nerves and muscles used in seeing, hearing, walking, talking, and eating.
The spinal cord - Connects the brain to nerves in most parts of the body. Spinal cord nerves carry messages between the brain and the rest of the body.
Signs & Symptoms
These are the most common signs of a brain or spinal cord tumor:
- Morning headache or headache that goes away when standing
- Frequent nausea and vomiting
- Vision, hearing, and speech problems
- Loss of balance and trouble walking
- Weakness on one side of the body
- Numbness on one side of the body
- Unusual sleepiness or change in activity level
- Unusual changes in personality or behavior
- Trouble with thinking and memory
Spinal Cord Tumors
- Back pain or pain that spreads from the back towards the arms or legs
- A change in bowel habits or trouble urinating
- Weakness in the legs
- Numbness in the legs or trunk
- Trouble walking
Diagnosis & Staging
There are a number of diagnostic tests used to find a brain or spinal cord tumor.
Your doctor will assess your overall health. You will be tested for fever, high blood pressure and swollen lymph nodes.
Neurological (or “neuro) Exam
You will answer questions and perform tests that check brain, spinal cord, and nerve function. Are you walking normally? How well do your muscles, senses, and reflexes work?
Visual Field Exam
Your field of vision will be evaluated. Any loss of vision may be a sign of a tumor affecting the parts of the brain that affect eyesight. How much you can see when looking straight ahead? How much you can see in all other directions while looking forward?
If you have a family history of brain tumors, your doctor may recommend tests for an inherited syndrome.
One or more imaging test would be used to ultimately find a brain or spinal cord tumor:
- Magnetic Resonance Imaging (MRI) – This test uses nuclear magnetic resonance to take detailed pictures of the brain. During this test a dye called gadolinium may be used. It collects around the cancer cells so they show up brighter in the picture.
- Perfusion MRI- This test may also be done during the MRI to look at blood flow in the tumor.
- Magnetic Resonance Spectroscopy (MRS)- MRS is used to identify the chemical make-up of tumor tissue. It may also be done during the MRI.
- CT scan - This X-ray test creates detailed cross-sectional images of your brain and spinal cord. The CT scanner takes many pictures of the soft tissues in the body as it rotates around. This is usually done in emergency situations or if the patient cannot have a MRI.
- PET Scan - During this test a small amount of radioactive dye (often glucose (sugar)) is injected into a vein. The scanner rotates around the body and shows where the dye is found. Malignant tumor cells use more glucose than normal cells since they are more active, so in the pictures they look brighter.
- SPECT Scan - This test creates a 3-D picture of the brain with the use of a radioactive dye (injected through a vein or inhaled through the nose). Where cancer cells are growing, there will be more chemical reactions. These areas show the dye and look brighter in the picture. This scan may be done just before or after a CT scan.
- Angiogram - This test uses X-rays to look at blood vessels and the flow of blood in the brain. It is rarely used today.
If a tumor is found, surgery is often the next step. Surgery is used to both diagnose (with a biopsy) and treat brain cancer. Tissue samples are needed to name and stage the cancer, based on the World Health Organization (WHO) classification system for brain tumors.
A pathologist will grade tumors by reviewing tissue samples under a microscope. Grades range from “grade I” (benign or the least aggressive), to “grade IV” (malignant and the most aggressive).
A team of specialists will work together to treat a brain or spinal cord tumors. This team can include a neurosurgeon, neuro-oncologist, radiation oncologist, medical oncologist, neurologist, and endocrinologist.
Primary treatment options will depend on the specifics of your tumor type, location, and if/where it has spread. After getting advice from one team, you may want to get a second opinion from another. A second opinion can help you learn more about your options and gain a better sense of what to do.
Symptoms, such as headaches, swelling around the tumor or seizures are managed as well, with medication. Often, rehabilitation is necessary to address problems from damage to brain tissue. Physical, occupational, and speech therapists are experts in this area.
Brain & Spinal Cord Tumor Treatments
Several treatments are used for brain or spinal cord tumors. These include surgery, radiation therapy, chemotherapy, immunotherapy or a wearable device. A number of experimental targeted molecular therapies, immunotherapies, and drugs are available through clinical trials.
Surgery is often the first treatment used to remove as much of the tumor as possible. If the tumor(s) cannot be removed, at least a small sample will be used for a biopsy to diagnose and guide treatment. Surgery may be followed by radiation or chemotherapy to kill cancer cells left behind.
Radiation is used to destroy cancer cells, keep them from growing, or relieve symptoms. The way radiation therapy is given depends on the type and location of the tumor. The types used to treat brain and spinal tumors include:
- External beam radiation therapy (EBRT) – EBRT directs high doses of radiation to the tumor(s). To protect normal brain tissue, radiation oncologists will chose the option that will work best for you:
- Three-dimensional conformal radiation therapy (3D-CRT): 3D-CRT focuses several radiation beams at the tumor at once. The beams are directed by a computer with details on the tumor’s location.
- Intensity modulated radiation therapy (IMRT): IMRT also uses a computer to deliver radiation. The intensity of the radiation can be targeted to protect healthy tissue.
- Proton beam radiation therapy: Protons are different than X-rays, and are less likely to damage healthy tissue. It is used mainly for chordomas and brain tumors in children and young adults. Most cancer centers don’t offer proton radiation.
- Stereotactic radiosurgery - This is not surgery, but a type of radiation therapy. It is sometimes called gammaknife, X-Knife, or CyberKnife radiation. It can be given in just one or two sessions to target and destroy tumor tissue.
- Brachytherapy - This treatment places radioactive material inside or near the tumor to kill cells.
- Whole brain and spinal cord radiation therapy (craniospinal radiation) - This is used if the tumor has spread to the spinal cord covering (meninges) or into cerebrospinal fluid.
Chemotherapy uses drugs to stop the growth of cancer cells. It either kills the cells or stops them from dividing. It is a “systemic” treatment, affecting cancer cells throughout your body (and some healthy cells). They tend to cause well-known side effects. Some chemotherapy types are better at going through the blood-brain barrier than others.
Chemotherapy drugs are used alone or with others, in cycles, to treat brain tumors:
- Carmustine (as a wafer)
Targeted Molecular Therapies
Targeted therapy drugs are designed to work with a specific molecular target. They can find and stop specific cell signals known to help cancer cells grow and spread. These drugs work by targeting, for example, the blood supply to a tumor or by blocking a growth signal. They can destroy cancer cells with less harm to healthy cells. Some targeted therapies are used to deliver chemotherapy more directly to cancer cells.
Not all brain tumors have the same targets. Tests are used to learn which genes, proteins, or other factors may be “targeted” in your tumor.
The U.S. Food and Drug Administration (FDA) has approved two targeted drugs for brain tumor treatment: Avastin® (bevacizumab) for recurrent glioblastoma, and Afinitor® (everolimus) for subependymal giant cell astrocytoma.
Tumor Treating Fields
Tumor Treating Fields (TTF) is a new innovation for treating brain tumors. These are electrodes placed on the head to treat glioblastomas. The electrode pads are placed over a solid brain tumor with a type of “cap”. This wearable device delivers low-frequency electric currents that can block cells from dividing. It can stop or delay cancer cells from growing. It causes few side effects.
TTF is an FDA-approved wearable device for glioblastoma. Clinical trials have shown an approximately 3-month survival benefit when it is used with temozolomide chemotherapy for patients with newly-diagnosed glioblastoma.
These are vaccines or drugs that stimulate the immune system to kill cancer cells. They are being studied in clinical trials to see if they can treat primary and secondary brain tumors.
Clinical trials are research studies used to develop new treatments for brain and other tumors. They are important because they offer new options. Some clinical trials focus on treatment, others aim to improve a patient’s quality of life.
Drugs to Help with Symptoms
Brain tumors can cause swelling, headaches, seizures and hormonal problems. To help with these problems your doctor may prescribe:
- Corticosteroids - to reduce swelling
- Anti-seizure medications
Rehabilitation for Physical Symptoms
Physical symptoms like weakness, difficulty speaking, stiffness, problems with movement, etc. can be relieved with rehabilitative treatment (rehab). Every person with a brain tumor deserves to function well and should be evaluated for rehab.
Try to find a physical, occupational, and speech therapist who has worked with neurological disorders (rather than only sports injuries, for example):
- Physical therapists help patients improve walking, balance and strength. Some people experience permanent mobility problems. Physical or occupational therapists will offer exercises to support your range of motion. They make sure your body has proper positioning to help decrease pain and stiffness.
- Occupational therapists teach patients how to manage changes and regain skills for daily activities, such as cooking, writing, and driving.
- Speech therapists help people overcome problems with language. They teach patients how to improve their speech process and adjust how they verbalize or otherwise express ideas. Speech therapists also help with eating and swallowing caused by oral motor problems.
- Cognitive therapists help people develop exercises and strategies to overcome problems with thinking and memory that may result from the brain tumor.
There are devices and exercises that can be prescribed. Handrails, grab bars and bath or shower chairs are some. There are also tools to help with eating, dressing, and computer access. The Americans with Disabilities Act was created, in part, to help people with a disability go back to work with reasonable accommodations.