It is estimated that over 13,000 people will die of brain cancer in the U.S. This year. This type of cancer is characterized by the growth of cancer tissue within the skull. There are several types of brain cancer, such as primary, secondary, and malignant. Common symptoms of the condition include headaches, vomiting, and changes in speech. In general, treatment options include surgery, chemotherapy, and radiation therapy.
Brain tumors are a diverse group of diseases characterized by the abnormal growth of tissue contained within the skull. Brain tumors are also called neoplasms, and there are a number of types of brain tumors which are classified by the region in which they appear and their size. Brain tumors can be benign (without cancer cells) or malignant (contains cancer cells).
Other than leukemia and lymphoma, brain tumors are the most common type of cancer that occurs in children. In adults, brain tumors are usually the result of cancer that has spread from another part of the body, such as the breast or lungs. (Brain tumors and brain cancer are used interchangeably in this article to mean the same thing.)
The brain is a soft, spongy mass of tissue that is protected by the bones of the skull and three thin membranes called meninges.
Watery fluid called cerebrospinal fluid cushions the brain and flows through spaces between the meninges and the ventricles (spaces within the brain).
A network of nerves carries messages back and forth between the brain and the rest of the body. While some nerves go directly from the brain to the eyes, ears, and other parts of the head, other nerves run through the spinal cord to connect the brain with the other parts of the body. Within the brain and spinal cord, glial cells surround nerve cells and hold them in place.
The brain directs the things we choose to do (like walking and talking) and the things our body does without thinking (like breathing). The brain is also in charge of our senses (sight, hearing, touch, taste, and smell), memory, emotions, and personality. The three major parts of the brain include the cerebrum, the cerebellum, and the brain stem. Each area controls different activities.
Cerebrum
The cerebrum is the largest part of the brain and is located at the top of the brain. The cerebrum:
Uses information from our senses to tell us what is going on around us
Tells our body how to respond
Controls reading, thinking, learning, speech, and emotions.
The cerebrum is divided into the left and right cerebral hemispheres, which control separate activities. The right hemisphere controls the muscles on the left side of the body, and the left hemisphere controls the muscles on the right side of the body.
Cerebellum
The cerebellum is under the cerebrum at the back of the brain. The cerebellum controls balance and complex actions, like walking and talking.
Brain Stem
The brain stem connects the brain with the spinal cord. The brain stem controls:
Hunger and thirst
Breathing
Body temperature
Blood pressure
Basic body functions.
Cancer begins in cells, which are the building blocks that make up tissues. Tissues make up the organs of the body. Normally, cells grow and divide to form new cells as the body needs them. When cells grow old, they die, and new cells take their place. Sometimes, however, this orderly process goes wrong -- new cells form when the body does not need them, and old cells do not die when they should. These extra cells can form a mass of tissue called a growth or a tumor.
The different brain tumor types include benign, malignant, primary, and secondary. The most common types of primary tumors in the brain are gliomas, which begin in glial cells. Kinds of gliomas include astrocytoma and brain stem glioma. Other brain tumors that do not start in the glial cells include medulloblastoma, meningioma, germ cell tumor, and schwannoma.
Brain tumors can be benign (noncancerous) or malignant (cancerous).
Key information about benign brain tumors is as follows:
Benign brain tumors do not contain cancer cells
Usually, benign brain tumors can be removed
Benign brain tumors seldom grow back
Cells from benign tumors do not invade tissues around them or spread to other parts of the body
Benign tumors can press on sensitive areas of the brain and cause serious health problems
Unlike benign tumors in most other parts of the body, benign brain tumors can be life-threatening
In rare cases, a benign brain tumor may become malignant.
Malignant brain tumors contain cancer cells. Key information about these types of brain tumors is as follows:
Malignant brain tumors are generally more serious and can be life-threatening.
Malignant brain tumors are likely to grow rapidly and crowd or invade the surrounding healthy brain tissue.
In rare cases, cancer cells may break away from a malignant brain tumor and spread to other parts of the brain, to the spinal cord, or even to other parts of the body. The spread of cancer is called metastasis.
Brain tumors that begin in brain tissue are known as primary brain tumors. These tumors are named according to the type of cells or the part of the brain in which they begin. Secondary brain tumors begin in another part of the body. When cancer spreads from its original place to another part of the body, the new tumor will have the same kind of abnormal cells and the same name as the primary tumor. Cancer that spreads to the brain from another part of the body is different from a primary brain tumor. When cancer cells spread to the brain from another organ (such as the lung or breast), doctors may call the tumor in the brain a secondary brain tumor or metastatic tumor. Secondary tumors in the brain are far more common than primary brain tumors.
Primary Types
The most common primary brain tumors are gliomas, which begin in glial cells. There are many types of gliomas, including:
Astrocytoma
Brain stem glioma
Ependymoma
Oligodendroglioma
Mixed glioma.
When people say "brain cancer," they usually are referring to a glioma.
Astrocytoma
An astrocytoma is a tumor that arises from star-shaped glial cells called astrocytes. In adults, this brain tumor type most often arises in the cerebrum. In children, they occur in the brain stem, the cerebrum, and the cerebellum. A grade III astrocytoma is sometimes called an anaplastic astrocytoma. A grade IV astrocytoma is usually called a glioblastoma multiforme.
Brain Stem Glioma
A brain stem glioma is a tumor that occurs in the lowest part of the brain, called the brain stem. This type of brain tumor is usually diagnosed in young children and middle-aged adults. Brain stem gliomas are usually high-grade. Those that are high-grade or that spread widely throughout the brain stem are difficult to treat successfully. In order to prevent damage to healthy brain tissue, a brain stem glioma is usually diagnosed without a biopsy.
Ependymoma
An ependymoma usually begins in cells that line the spaces in the brain and around the spinal cord. These spaces contain cerebrospinal fluid, which is a liquid that cushions and protects the brain and spinal cord. These types of brain tumors are most commonly found in children and young adults.
Oligodendroglioma
Oligodendroglioma is a rare tumor that arises from cells that make up the fatty substance that covers and protects nerves. These tumors usually occur in the cerebrum. Oligodendroglioma grow slowly and usually do not spread into surrounding brain tissue. These tumors are most common in middle-aged adults.
Mixed Gliomas
Mixed gliomas are brain tumors that contain more than one type of cell. The prognosis for this kind of brain tumor will depend on the cell type and the highest grade present in the tumor.
Brain tumors that do not start in the glial cells include:
Medulloblastoma
Meningioma
Schwannoma
Craniopharyngioma
Germ cell tumor of the brain
Pineal region tumor.
Medulloblastoma
A medulloblastoma usually arises in the cerebellum. This brain tumor type forms from abnormal brain cells at an early stage in development. Medulloblastoma is the most common brain tumor in children. It is sometimes called a primitive neuroectodermal tumor. This tumor may spread from the brain to the spine through the cerebrospinal fluid.
Meningioma
A meningioma is a brain tumor that develops in the meninges, which is the protective membrane covering the brain directly underneath the skull. This kind of tumor is usually benign, grows slowly, and usually occurs in women between 30 and 50 years of age.
Schwannoma
A schwannoma is a tumor that arises from a Schwann cell. Schwann cells line the nerve in the inner ear that controls balance and hearing. This tumor is also called an acoustic neuroma, and it usually occurs in adults.
Craniopharyngioma
A craniopharyngioma is a brain tumor that grows at the base of the brain, near the pituitary gland. Craniopharyngiomas do not spread, but may interfere with important structures near them, causing serious problems. This type of brain tumor usually occurs in children.
Germ Cell Tumor of the Brain
Germ cell tumors arise from germ cells, which are cells that are meant to form sperm in the testicles or eggs in the ovaries. These cells may travel to other parts of the body and form tumors. The most common germ cell tumor of the brain is a germinoma. Other types of germ cell tumors include:
Embryonal cell carcinomas
Choriocarcinomas
Teratomas.
Germ cell tumors can occur anywhere in the body, and can be either benign or malignant. Germ cell tumors usually form in the center of the brain, near the pineal gland, and can spread to other parts of the brain and spinal cord. This kind of tumor usually occurs in children.
Pineal Region Tumor
Pineal tumors form in or near the pineal gland. The pineal gland is a tiny organ in the brain located between the cerebrum and cerebellum. It produces the hormone melatonin, which is a substance that helps control our sleeping and waking cycle. There are several kinds of pineal tumors. However, brain tumors of this type are rare.
The symptoms of a low-grade or benign brain tumor depend on its size and where it is in the brain. Some slow-growing tumors may not cause symptoms at first.
When symptoms do occur, it is because the brain tumor is either putting pressure on the brain or preventing an area of the brain from functioning properly.
If the tumor causes an increase in pressure inside the skull, it can lead to the following symptoms:
epilepsy or fits, which can be either major seizures or twitching in one area of the body
severe, persistent headache
irritability, drowsiness, apathy or forgetfulness
vomiting, which is sometimes sudden and for no apparent reason
dizziness
partial loss of vision or hearing
hallucinations
personality changes, including abnormal and uncharacteristic behavior
It is important to see a doctor if you develop a persistent and severe headache that does not have any obvious cause, especially if you also have unexpected vomiting.
Different areas of the brain control different functions, so any loss of brain function will depend on where the tumor is located. For example:
A tumor affecting the frontal lobe may cause changes in personality, weakness in one side of the body and loss of smell.
A tumor affecting the parietal lobe may cause difficulty in speaking, understanding words, writing, reading and co-ordinating certain movements. There may also be numbness in one side of the body.
A tumor affecting the occipital lobe may cause loss of vision on one side.
A tumor affecting the temporal lobe may cause fits or blackouts, a sensation of strange smells and problems with speech and memory.
A tumor affecting the cerebellum may cause a loss of co-ordination, difficulty walking and speaking, flickering of the eyes, vomiting and a stiff neck.
A tumor affecting the brain stem may cause unsteadiness and difficulty walking, facial weakness, double vision and difficulty speaking and swallowing.
Brain
tumors that begin in the brain
Primary brain tumors originate in the brain itself or in tissues
close to it, such as in the brain-covering membranes (meninges),
cranial nerves, pituitary gland or pineal gland. Primary brain tumors
begin when normal cells acquire errors (mutations) in their DNA.
These mutations allow cells to grow and divide at increased rates and
to continue living when healthy cells would die. The result is a mass
of abnormal cells, which forms a tumor.
Primary brain tumors are much less common than are secondary brain tumors, in which cancer begins elsewhere and spreads to the brain. Many different types of primary brain tumors exist. Each gets its name from the type of cells involved. Examples include:
Acoustic neuroma (schwannoma)
Astrocytoma, also known as glioma, which includes anaplastic astrocytoma and glioblastoma
Ependymoma
Ependymoblastoma
Germ cell tumor
Medulloblastoma
Meningioma
Neuroblastoma
Oligodendroglioma
Pineoblastoma
Cancer
that begins elsewhere and spreads to the brain
Secondary (metastatic) brain tumors are tumors that result from
cancer that starts elsewhere in your body and then spreads
(metastasizes) to your brain. Secondary brain tumors most often occur
in people who have a history of cancer. But in rare cases, a
metastatic brain tumor may be the first sign of cancer that began
elsewhere in your body.
Secondary brain tumors are far more common than are primary brain tumors. Any cancer can spread to the brain, but the most common types include:
Breast cancer
Colon cancer
Kidney cancer
Lung cancer
Melanoma
No one knows the exact brain cancer cause or causes, and doctors can seldom explain why one person will get brain cancer and another person will not. However, brain cancer research has shown that people with certain risk factors, such as being male or Caucasian, are more likely than others to develop the disease. While these risk factors are not necessarily causes of the disease, they may act together to increase a person's risk of developing it.
While risk factors are not causes of the condition, studies have found a number of factors that may increase a person's risk of developing it. Specific risk factors for developing a primary brain tumor include:
Being male
Race
Age
Family history
Exposure to radiation or certain chemicals.
Being Male
In general, brain tumors are more common in males than in females. However, meningiomas are more common in females.
Race
Brain tumors occur more often in Caucasians than in people of other races.
Age
Most brain tumors are detected in people who are 70 years of age or older. However, brain tumors are the second most common cancer in children. (Leukemia is the most common childhood cancer.) Brain tumors are most common in children younger than 8 years of age.
Family History
People with family members who have gliomas may be more likely to develop this disease.
Exposure to Radiation and Certain Chemicals
Exposure to radiation or certain chemicals that will increase a person's risk of developing brain cancer include:
Radiation -- Workers in the nuclear industry have an increased risk of developing a brain tumor.
Formaldehyde -- Pathologists and embalmers who work with formaldehyde have an increased risk of developing brain cancer. However, scientists have not found an increased risk of developing brain cancer among other types of workers who are exposed to formaldehyde.
Vinyl chloride -- Workers who make plastics may be exposed to vinyl chloride, which is a chemical that can increase a person's risk of developing brain cancer.
Acrylonitrile -- People who make textiles and plastics may be exposed to acrylonitrile. Exposure to acrylonitrile can potentially increase a person's risk of developing brain cancer.
Scientists are currently investigating cell phones and head injuries as possible causes of brain tumors. However, studies thus far have not found an increased risk of brain tumors among people who use cell phones or among people who have had head injuries.
Although brain cancer research scientists do not know the cause or causes of the disease, they are continuing to search. People who think that they may be at risk of brain cancer should discuss this concern with their doctor who can suggest ways to reduce the risk of developing brain cancer and can plan an appropriate schedule for checkups.
Treatment for a brain tumor depends on the type, size and location of the tumor, as well as your overall health and your preferences. Your doctor can tailor treatment to fit your particular situation.
Surgery
If the brain tumor is located in a place that makes it accessible
for an operation, your surgeon will work to remove as much of your
brain tumor as possible. In some cases, tumors are small and easy to
separate from surrounding brain tissue, which makes complete surgical
removal possible. In other cases, tumors can't be separated from
surrounding tissue or they're located near sensitive areas in your
brain, making surgery risky. In these situations your doctor may try
to remove as much of the tumor as is safe. Even removing a portion of
the brain tumor may help reduce signs and symptoms you experience. In
some cases only a small biopsy is taken to confirm the diagnosis.
Surgery to remove a brain tumor carries risks, such as infection and bleeding. Other risks may depend on the part of your brain where your tumor is located. For instance, surgery on a tumor near nerves that connect to your eyes may carry a risk of vision loss.
Radiation
therapy
Radiation therapy uses
beams of high-energy particles, such as X-rays, to kill tumor cells.
Radiation therapy can come from a machine outside your body (external
beam radiation), or, in very rare cases, radiation can be placed
inside your body close to your brain tumor (brachytherapy).
External beam radiation can focus just on the area of your brain where the tumor is located, or it can be applied to your entire brain (whole brain radiation). Whole brain radiation is sometimes used after surgery to kill tumor cells that might have been left behind.
Side effects of radiation therapy depend on the type and dose of radiation you receive. In general it can cause fatigue, headaches and scalp irritation.
Radiosurgery
Stereotactic radiosurgery is not a form of surgery in the
traditional sense. Instead, radiosurgery uses multiple beams of
radiation to give a highly focused form of radiation treatment to
kill the tumor cells in a very small area. Each beam of radiation
isn't particularly powerful, but the point where all the beams meet —
at the brain tumor — receives a very large dose of radiation to
kill the tumor cells.
Radiosurgery is typically done in one treatment, and in most cases you can go home the same day. Side effects may include fatigue, headache and nausea.
Chemotherapy
Chemotherapy uses drugs to kill tumor cells. Chemotherapy drugs
can be taken orally in pill form or injected into a vein
(intravenously).
Another type of chemotherapy can be placed during surgery. When removing all or part of the brain tumor, your surgeon may place one or more disk-shaped wafers in the space left by the tumor. These wafers slowly release a chemotherapy drug over the next several days.
Chemotherapy side effects depend on the type and dose of drugs you receive. Systemic chemotherapy can cause nausea, vomiting and hair loss.
Targeted
drug therapy
Targeted drug
treatments focus on specific abnormalities present within cancer
cells. By blocking these abnormalities, targeted drug treatments can
cause cancer cells to die. Many targeted drug therapies are very new
and still undergoing careful study in clinical trials.
One targeted drug therapy used to treat brain tumors is bevacizumab (Avastin). This drug, given through a vein (intravenously), stops the formation of new blood vessels, cutting off blood supply to a tumor and killing the tumor cells.
Rehabilitation
after treatment
Because brain
tumors can develop in parts of the brain that control motor skills,
speech, vision and thinking, rehabilitation may be a necessary part
of recovery. Your doctor may refer you to services that can help,
such as:
Physical therapy can help you regain lost motor skills or muscle strength.
Occupational therapy can help you get back to your normal daily activities, including work, after a brain tumor or other illness.
Speech therapy with specialists in speech difficulties (speech pathologists) can help if you have difficulty speaking.
Tutoring for school-age children can help kids cope with changes in their memory and thinking after a brain tumor.
The brain cancer survival rate indicates the percentage of people with a certain type and stage of brain cancer who survive the disease for a specific period of time after their diagnosis. In most cases, statistics refer to the 5-year brain cancer survival rate. The 5-year brain cancer survival rate is the percentage of people who are alive 5 years after a brain cancer diagnosis, whether they have few or no signs or symptoms of brain cancer, are free of disease, or are having treatment for brain cancer. The brain cancer survival rate is based on large groups of people, and it cannot be used to predict what will happen to a particular patient. No two patients are alike, and brain cancer treatment and responses to treatment vary greatly.
In general, the brain cancer survival rate will depend on:
The type of brain cancer (see Types of Brain Tumors above)
The size and location of brain cancer
The brain cancer stage
The brain cancer grade
The patient's general health.
Survival rates can be calculated by different methods for different purposes. The brain cancer survival rates presented here are based on the relative survival rate. The relative survival rate measures the survival of patients with brain cancer in comparison to the general population to estimate the effect of cancer. The overall 5-year relative brain cancer survival rate for 1995-2001 was 33.3 percent.
The 5-year relative survival rates for brain cancer by race and sex were as follows:
32.1 percent for Caucasian men
33.5 percent for Caucasian women
37.7 percent for African-American men
37.5 percent for African-American women.