Brain Cancer Facts
What is brain cancer?
Primary brain cancer develops from cells within the brain. Part of the central nervous system (CNS), the brain is the control center for vital functions of the body, including speech, movement, thoughts, feelings, memory, vision, hearing and more.
Primary brain tumors are classified by the type of cell or tissue the tumor affects, and the location and grade of the tumor. Tumor cells may travel short distances within the brain, but generally won't travel outside of the brain itself.
When cancer develops elsewhere in the body and spreads (metastasizes) to the brain, it’s called a secondary brain tumor, or metastatic brain cancer. Metastatic brain tumors are more common than primary brain tumors. Some cancers that commonly spread to the brain include lung, colon, kidney and breast cancers.
Brain cancer incidence
Each year, over 190,000 people in the United States are diagnosed with a brain tumor (National Brain Tumor Society).
It is estimated that 23,770 new cases of brain and other nervous system cancers will be diagnosed in 2016, with the median age at the time of diagnosis being 58 (National Cancer Institute).
How brain cancer develops
The brain and spinal cord together make up the central nervous system (CNS). Cancer can begin in the CNS or, more commonly, it can spread there.
Primary brain tumors are tumors that form from cells within the brain. Not all primary brain tumors are the same. Primary brain tumors can be divided into malignant or benign tumors.
- Benign primary brain tumors are not cancerous. They grow slowly, and tend to be more amendable to surgical or other treatments. However, benign brain tumors can still damage normal brain tissue and cause serious problems.
- Malignant brain tumors are more aggressive by definition. They grow more quickly and invade local structures more aggressively.
Metastatic brain tumors are tumors that spread (metastasize) to the brain from another location in the body, such as the lung, colon, breast or kidney. Metastatic brain tumors are more common than primary brain tumors.
Brain cancer symptoms
Symptoms of brain cancer depend on several factors, including the tumor type, size, location and extent, as well as age, health history and more.
Some common signs of brain cancer include headache, weakness, numbness, nausea, vomiting or seizures. Some individuals may not feel right cognitively or have visual, speech or coordination problems. The symptoms may be subtle or develop gradually.
Symptoms of brain cancer are influenced by which part of the brain is involved and the functional system it effects (e.g., motor, sensory, language, etc.). For example, vision problems may result from a tumor near the optic nerve. A tumor in the front part of the brain may affect the ability to concentrate and think. A tumor located in an area that controls motor function may cause weakness, numbness or difficulty with speech. Any tumor that is significantly large can create multiple symptoms because of the pressure created by the mass.
Brain cancer risk factors
Gender: There is no general rule that covers all brain cancers. Certain cancers, like meningiomas, are twice as likely to develop in women. Medulloblastomas are more frequently found in males.
Age: In general, the frequency of brain cancer increases with age, with more occurrences in individuals age 65 and older. The age factor varies depending on the cell type and location of the tumor. Adults have a very low risk of developing medulloblastomas, while gliomas are most common in adults. The incidence of meningiomas and craniopharyngiomas are far more frequent in adults over age 50, but again, these tumors may occur at any age.
Compromised immune system: Some people with compromised immune systems have an increased risk of developing lymphomas of the brain.
Genetic links: Family history may affect the likelihood of developing certain diseases. Von Hippel-Lindau disease, Li-Fraumeni syndrome, and Neurofibromatosis (NF1 and NF2) are inherited conditions that have been found in families with a history of rare brain tumors. Otherwise, there is little evidence that brain cancer runs in families.
Chemical exposure: Exposure to certain industrial chemicals or solvents has been linked to an increased risk of developing brain cancer. Although it is not conclusive, there is evidence that there is a higher incidence of certain types of brain tumors in individuals who work in oil refining, rubber manufacturing and drug manufacturing.
© 2014 American Brain Tumor Association