Each year, according to the National Brain Tumor Foundation, approximately 190,000 people in the United States will be diagnosed with a primary or metastatic brain tumor.
A tumor is an abnormal mass of tissue in which the cells grow and multiply without restraint, apparently unregulated by the mechanisms that control normal cells. There are two basic kinds of tumors:
- Primary brain tumors originate in the brain and, in most cases, do not travel to other parts of the body.
- Metastatic (secondary) brain tumors have spread to the brain from another part of the body. These are the most common form of brain tumor, affecting 20% to 40% of all cancer patients.
Since there are over 120 different types of central nervous system tumors, diagnosing and treating brain and spinal cord cancers can be especially complicated.
Types of Adult Tumors
The following descriptions of primary brain tumors are from the National Cancer Institute and are used to group adult tumors:
- Astrocytomas: Start in brain cells called astrocytes. There are different kinds of astrocytomas, which are defined by how the cancer cells look under a microscope.
- Brain Stem Gliomas: Located in the bottom part of the brain that connects to the spinal cord.
- Cerebellar Astrocytomas: Occur in the cerebellum, which is just above the back of the neck; they usually grow slowly and do not usually spread.
- Ependymomas: Begin in the cells that line the passageways in the brain where cerebrospinal fluid is made and stored. There are different kinds of ependymal tumors, which are defined by how the cells look under a microscope.
- Well-Differentiated Ependymomas: Cells look very much like normal cells and grow quite slowly.
- Anaplastic Ependymomas: Do not look like normal cells and grow more quickly than well-differentiated ependymal tumors.
- Ependymoblastomas: Rare cancers that usually occur in children; they may grow very quickly.
- Oligodendrogliomas: Begin in the brain cells called oligodendrocytes, which provide support and nourishment for the cells that transmit nerve impulses. There are different types of oligodendroglial tumors, which are defined by how the cells look under a microscope.
Other Types of Brain Tumors
- Choroid Plexus Tumors: The choroid plexus makes the fluid that fills the ventricles and surrounds the brain and spinal cord. Tumors of the choroid plexus can grow slowly (choroid plexus papilloma) or grow more rapidly (anaplastic choroid plexus papilloma). The rapidly growing tumors are more likely to spread to other places in the brain and to the spinal cord.
- Craniopharyngiomas: Occur near the pituitary gland, a small organ about the size of a pea; this gland is located just above the back of the nose and controls many of the body’s functions.
- Germ Cell Tumors: Usually arise from the sex cells, but can arise from the pineal gland. There are different kinds of germ cells, including germinomas, embryonal carcinomas, choriocarcinomas, and teratomas.
- Malignant Meningiomas: A rare tumor that grows more quickly than other meningiomas.
- Medulloblastomas: Begin in the lower part of the brain; they are almost always found in children or young adults. This type of cancer may spread from the brain to the spine.
- Meningiomas: Occur in the membranes (the meninges) that cover and protect the brain and spinal cord. Meningiomas usually grow slowly.
- Mixed Gliomas: Occur in more than one type of brain cell, including cells of astrocytes, ependymal cells, and/or eoligodendrocytes.
- Pineal Parenchymal Tumors: Found in or around the pineal gland located near the center of the brain. The tumors can be slow-growing (pineocytomas) or fast-growing (pineoblastomas). Astrocytomas may also start here.
Brain & Spinal Cord Cancers: Symptoms
The symptoms of both primary and metastatic brain tumors depend mainly on the location in the brain and the size of the tumor. Since each area of the brain is responsible for specific functions, symptoms vary considerably. For example:
- Frontal lobe tumors may cause weakness, paralysis, mood disturbances, difficulty thinking, confusion and disorientation, and wide emotional mood swings.
- Parietal lobe tumors may cause seizures, numbness or paralysis, difficulty with handwriting, inability to perform simple mathematical problems, difficulty with certain movements, and loss of the sense of touch.
- Occipital lobe tumors can cause loss of vision in half of each visual field, visual hallucinations, and seizures.
- Temporal lobe tumors can cause seizures, perceptual and spatial disturbances, and a loss of ability to speak or understand speech.
- Cerebellum tumors may cause balance problems, loss of coordination, headaches, and vomiting.
- Hypothalamus tumors may cause emotional changes and changes in the perception of hot and cold.
With the exception of tumors of the cerebellum, a tumor on one side of the brain causes symptoms and impairment on the opposite side of the body. For example, a tumor on the left side of the brain may cause numbness in the right arm.
Spinal cord cancer is rarer than brain cancer. Pain in the back is a common symptom. Loss of feeling or movement in the legs and arms and muscle weakness may follow.
Brain & Spinal Cord Cancers: Diagnosis
There are no screening tests to detect central nervous system tumors early. If a brain tumor is suspected, you will be referred to a neurologist or neurosurgeon. After a preliminary neurological examination and consideration of your symptoms, your doctor may request computerized tomography (CT) scans, and magnetic resonance (MR) imaging to determine if more definitive procedures are needed. Other studies, such as X-ray films of the head and skull, an electroencephalogram (EEG), or radioisotopic brain scans, may also be performed. A biopsy of the tumor tissue, removal of the tumor, or in some cases a lumbar puncture (spinal tap) may also be performed to provide a definitive diagnosis.
Brain & Spinal Cord Cancers: Treatment
No two tumors are alike. Numerous factors can determine treatment outcomes, including genetics, location of the tumor, age and cognition, and a patient’s general health. Since no two people have the same physical makeup, all of these factors play an important role in the treatment and outcomes for tumor patients.
Treatment for central nervous system cancers includes:
- Surgery: New surgical techniques and tools allow for the precise and safe removal of tumors from many parts of the brain. Surgery may be followed by radiation and/or chemotherapy.
- Radiation Therapy: Radiation therapy uses high-energy rays to kill or shrink cancer cells. The radiation may come from outside of the body (external radiation) or from radioactive materials placed directly in the tumor (internal or implant radiation). Radiation therapy may be used to reduce the size of a cancer before surgery, to destroy any remaining cancer cells after surgery, or, in some cases, as the main treatment.
- Chemotherapy: Chemotherapy refers to the use of drugs whose main effect is either to kill or slow the growth of rapidly multiplying cells. Chemotherapy usually includes a combination of drugs. Some chemotherapy drugs are injected directly into the bloodstream while others can be taken as pills at home.
These therapies may be delivered alone or in combination.
Brain & Spinal Cord Cancers: Resources
National Center for Complementary and Alternative Medicine
National Institutes of Health
9000 Rockville Pike
Bethesda, Maryland 20892
Brain Tumor Action Network
38940 1st Avenue
Zephyrhills, FL 33542
Brain Tumor Society
124 Watertown Street, Suite 2D
Watertown, MA 02472
National Cancer Institute
9000 Rockville Pike
Bethesda, MD 20892
The Brain Tumor Center at Duke
Duke Comprehensive Cancer Center
The Musella Foundation for Brain Tumor Research and Information
1100 Peninsula Blvd.
Hewlett, NY 11557