Brain cancer facts:
- An estimated 20,500 individuals are diagnosed with brain cancer and other nervous system cancers annually in the United States.
- Approximately 12,700 people die from brain cancers each year.
- Brain cancer accounts for approximately 1.4 percent of all cancers and 2.2 percent of all cancer-related deaths.
Most cells in the body grow and divide in an orderly way to form new cells as they are needed to keep the body healthy and working properly. When cells lose the ability to control their growth, they divide too often and without any order. The extra cells form a mass of tissue called a tumor. Tumors are benign or malignant.
Benign brain tumors do not contain cancer cells. Usually these tumors can be removed, and they are less likely to recur. Benign brain tumors have clear borders. Although they do not invade nearby tissue, they can press on sensitive areas of the brain and cause symptoms such as headaches.
Malignant brain tumors contain cancer cells. These tumors interfere with vital functions and are life-threatening. Malignant brain tumors are likely to grow rapidly and crowd or invade the tissue around them. Like a plant, these tumors may put out "roots" that grow into healthy brain tissue. If a malignant tumor remains compact and does not have roots, it is said to be encapsulated. When an otherwise benign tumor is located in a vital area of the brain and interferes with vital functions, it may be considered malignant (even though it contains no cancer cells).
Doctors refer to some brain tumors by grade – from low grade (grade I) to high grade (grade IV). The grade of a tumor refers to the way the cells look under a microscope. Cells from higher grade tumors are more abnormal looking and generally grow faster than cells from lower grade tumors; higher grade tumors are more malignant than lower grade tumors.
Tumors that begin in brain tissue are known as primary brain tumors. Primary brain tumors are classified by the type of tissue in which they begin. The most common brain tumors are gliomas, which begin in the glial (supportive) tissue.
There are several types of gliomas:
- Brain stem gliomas
There are other types of brain tumors that do not begin in glial tissue:
- Germ cell tumors
- Pineal region tumors
Metastasis is the spread of cancer. Cancer that begins in one part of the body may spread to the brain and cause secondary tumors. These tumors are not the same as primary brain tumors. Cancer that spreads to the brain is the same disease and has the same name as the original (primary) cancer. For example, if lung cancer spreads to the brain, the disease is called metastatic lung cancer because the cells in the secondary tumor resemble abnormal lung cells, not abnormal brain cells. Secondary tumors in the brain are far more common than primary brain cancer.
Brain metastases most frequently originate with lung or breast cancer. Treatment is much the same as that for primary brain tumors, with radiotherapy being used most often. For some patients, surgery is used to remove the tumors from the brain.
Please use the following links to access comprehensive brain cancer information provided by the National Cancer Institute from its PDQ® Database.
Learn more about adult brain tumors...
Learn more about childhood brain stem glioma...
Learn more about childhood brain tumors...
Learn more about childhood cerebral astrocytoma/malignant glioma...
Learn more about childhood ependymoma...
Learn more about childhood medulloblastoma...
Learn more about childhood supratentorial primitive neuroectodermal tumors and penioblastoma...
Learn more about childhood visual pathway and hypothalamic glioma...