Each year, over 190,000 people in the United States are diagnosed with a primary or metastatic brain tumor (National Brain Tumor Society). Metastatic brain tumors make up the majority, with an estimated incidence of about 10 times that of primary brain tumors. About 17,000 Americans are diagnosed with primary brain cancer each year (National Cancer Institute). While brain tumors can develop at any age, studies show that brain cancer incidence occur most commonly in children younger than eight years old and adults over age 50.
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.