Fact: Statistics suggest that brain cancer occurs infrequently
(1.4% of all new cancer patients per year)
What is brain cancer?
Brain cancer is a disease of the brain in which cancer cells (malignant cells) arise in the brain tissue. Cancer cells grow to form a mass of cancer tissue (tumor) that interferes with brain functions such as muscle control, sensation, memory, and other normal body functions. Tumors composed of cancer cells are called malignant tumors, and those composed of mainly noncancerous cells are called benign tumors. Cancer cells that develop from brain tissue are called primary brain tumors while tumors that spread from other body sites to the brain are termed metastatic or secondary brain tumors.
Statistics suggest that brain cancer occurs infrequently (1.4% of all new cancer patients per year), so it is not considered to be a common illness and is likely to develop in about 23,770 new people per year with about 16,050 deaths as estimated by the National Cancer Institute (NCI) and the American Cancer Society. Only about 5% of brain tumors may be due to hereditary genetic conditions such as neurofibromatosis, tuberous sclerosis, and a few others.
Primary Brain Cancers
The brain is made up of many different types of cells.
- Some brain cancers occur when one type of cell transforms from its normal characteristics. Once transformed, the cells grow and multiply in abnormal ways.
- As these abnormal cells grow, they become a mass, or tumor.
- The brain tumors that result are called primary brain tumors because they originate in the brain.
- The most common primary brain tumors are gliomas, meningiomas, pituitary adenomas, vestibular schwannomas, and primitive neuroectodermal tumors (medulloblastomas). The term glioma includes glioblastomas, astrocytomas, oligodendrogliomas, and ependymomas.
- Most of these are named after the part of the brain or the type of brain cell from which they arise.
Metastatic Brain Cancer
Metastatic brain tumors are made of cancerous cells from a tumor elsewhere in the body. The cells spread to the brain from another tumor in a process called metastasis. This is the most common type of brain tumor.
The signs and symptoms of a brain tumor vary greatly and depend on the brain tumor's size, location and rate of growth.
General signs and symptoms caused by brain tumors may include:
- New onset or change in pattern of headaches
- Headaches that gradually become more frequent and more severe
- Unexplained nausea or vomiting
- Vision problems, such as blurred vision, double vision or loss of peripheral vision
- Gradual loss of sensation or movement in an arm or a leg
- Difficulty with balance
- Speech difficulties
- Confusion in everyday matters
- Personality or behavior changes
- Seizures, especially in someone who doesn't have a history of seizures
- Hearing problems
Brain tumors that begin in the brainPrimary 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.
In adults, 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.
- Gliomas. These tumors begin in the brain or spinal cord and include astrocytomas, ependymomas, glioblastomas, oligoastrocytomas and oligodendrogliomas.
- Meningiomas. A meningioma is a tumor that arises from the membranes that surround your brain and spinal cord (meninges). Most meningiomas are noncancerous.
- Acoustic neuromas (schwannomas). These are benign tumors that develop on the nerves that control balance and hearing leading from your inner ear to your brain.
- Pituitary adenomas. These are mostly benign tumors that develop in the pituitary gland at the base of the brain. These tumors can affect the pituitary hormones with effects throughout the body.
- Medulloblastomas. These are the most common cancerous brain tumors in children. A medulloblastoma starts in the lower back part of the brain and tends to spread through the spinal fluid. These tumors are less common in adults, but they do occur.
- Germ cell tumors. Germ cell tumors may develop during childhood where the testicles or ovaries will form. But sometimes germ cell tumors affect other parts of the body, such as the brain.
- Craniopharyngiomas. These rare, noncancerous tumors start near the brain's pituitary gland, which secretes hormones that control many body functions. As the craniopharyngioma slowly grows, it can affect the pituitary gland and other structures near the brain.
Cancer that begins elsewhere and spreads to the brainSecondary (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.
In adults, secondary brain tumors are far more common than are primary brain tumors.
Any cancer can spread to the brain, but common types include:
- Breast cancer
- Colon cancer
- Kidney cancer
- Lung cancer
In most people with primary brain tumors, the cause of the tumor is not clear. But doctors have identified some factors that may increase your risk of a brain tumor.
Risk factors include:
- Exposure to radiation. People who have been exposed to a type of radiation called ionizing radiation have an increased risk of brain tumor. Examples of ionizing radiation include radiation therapy used to treat cancer and radiation exposure caused by atomic bombs.
- Family history of brain tumors. A small portion of brain tumors occurs in people with a family history of brain tumors or a family history of genetic syndromes that increase the risk of brain tumors.
If it's suspected that you have a brain tumor, your doctor may recommend a number of tests and procedures, including:
- A neurological exam. A neurological exam may include, among other things, checking your vision, hearing, balance, coordination, strength and reflexes. Difficulty in one or more areas may provide clues about the part of your brain that could be affected by a brain tumor.
Imaging tests. Magnetic resonance imaging (MRI) is commonly used to help diagnose brain tumors. In some cases a dye may be injected through a vein in your arm during your MRI study.
A number of specialized MRI scan components — including functional MRI, perfusion MRI and magnetic resonance spectroscopy — may help your doctor evaluate the tumor and plan treatment.
Sometimes other imaging tests are recommended, including computerized tomography (CT). Positron emission tomography (PET) may be used for brain imaging, but is generally not as useful for creating images of brain cancer as it is for other types of cancer.
- Tests to find cancer in other parts of your body. If it's suspected that your brain tumor may be a result of cancer that has spread from another area of your body, your doctor may recommend tests and procedures to determine where the cancer originated. One example might be a CT or PET scan to look for signs of lung cancer.
Collecting and testing a sample of abnormal tissue (biopsy). A biopsy can be performed as part of an operation to remove the brain tumor, or a biopsy can be performed using a needle.
A stereotactic needle biopsy may be done for brain tumors in hard to reach areas or very sensitive areas within your brain that might be damaged by a more extensive operation. Your neurosurgeon drills a small hole into your skull. A thin needle is then inserted through the hole. Tissue is removed using the needle, which is frequently guided by CT or MRI scanning.
The biopsy sample is then viewed under a microscope to determine if it is cancerous or benign. Sophisticated laboratory tests can give your doctor clues about your prognosis and your treatment options.
Treatment for a brain tumor depends on the type, size and location of the tumor, as well as your overall health and your preferences.
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 the 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 removes as much of the tumor as is safe.
Even removing a portion of the brain tumor may help reduce your signs and symptoms.
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 uses high-energy beams, such as X-rays or protons, 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 most often used to treat cancer that spreads to the brain from some other part of the body and forms multiple tumors in the brain.
A newer form of radiation therapy using proton beams is being studied for use in people with brain tumors. For tumors that are very close to sensitive areas of the brain, proton therapy may reduce the risk of side effects associated with radiation. But proton therapy hasn't proved to be more effective than standard radiation therapy with X-rays.
Side effects of radiation therapy depend on the type and dose of radiation you receive. Common side effects during or immediately following radiation include fatigue, headaches, memory loss and scalp irritation.
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.
There are different types of technology used in radiosurgery to deliver radiation to treat brain tumors, such as a Gamma Knife or linear accelerator. Radiosurgery is typically done in one treatment, and in most cases you can go home the same day.
Chemotherapy uses drugs to kill tumor cells. Chemotherapy drugs can be taken orally in pill form or injected into a vein (intravenously). The chemotherapy drug used most often to treat brain tumors is temozolomide (Temodar), which is taken as a pill. Many other chemotherapy drugs are available and may be used depending on the type of cancer.
Chemotherapy side effects depend on the type and dose of drugs you receive. Chemotherapy can cause nausea, vomiting and hair loss.
Tests of your brain tumor cells can determine whether chemotherapy will be helpful for you. The type of brain tumor you have also is helpful in determining whether to recommend chemotherapy.
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.
Targeted therapy drugs are available for certain types of brain tumors, and many more are being studied in clinical trials. Many different forms of targeted therapy are being developed.
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. Depending on your needs, your doctor may refer you to:
- Physical therapy to help you regain lost motor skills or muscle strength
- Occupational therapy to 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) to help if you have difficulty speaking
- Tutoring for school-age children to help kids cope with changes in their memory and thinking after a brain tumor
Want to learn more?
The following organizations and/or websites offer additional information and education about Brain Cancer. They are listed in Alphabetical order without any preference or prejudice. Listing these organizations is not a recommendation or referral in any regard for seeking treatment or consultation or support for treatment.
Cancer Treatment Centers of America
National Cancer Institute
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