Brain cancer is an abnormal growth of cells in the brain, which result in a collection of cells called a brain tumor. If the abnormal cells were originally brain cells that started to grow uncontrollably, it is a primary brain tumor. If the abnormal cells originated in another part of the body, such as the lung or breast, and were carried to the brain by the blood or other body fluid, then it is considered a metastatic brain tumor. More than 18,000 cases of primary brain tumors1 and more than 170,000 brain metastases2 are diagnosed in United States each year.
Primary brain tumors
There are many types of primary brain tumors, including meningiomas, pituitary adenomas, schwannomas and gliomas, which are divided into astrocytomas, ependymomas, medulloblastomas and oligodendrogliomas. Each primary brain tumor is categorized based on the type of normal brain cell from which they originated and has its own unique characteristics and growth patterns. Gliomas account for 40 percent of all primary brain tumors and it is common for them to spread from the brain to other parts of the body1.The most aggressive type of glioma is called glioblastoma multiforme2.
Metastatic brain tumors
The cells that form metastatic brain tumors travel to the brain from other parts of the body through the bloodstream, along nerves or within the fluid surrounding the spinal cord and brain. These cells most commonly originate in tumors within the lung, breast, skin or colon, and are deposited in the brain where they grow into a tumor.3
Both primary and metastatic brain tumors can be very dangerous because they can compress sensitive brain tissue and nerves within the head, causing patients to experience symptoms such as vision loss, hearing loss, difficulties with balance, pain or seizures. As these tumors grow larger, they can be life-threatening because they disrupt critical parts of the brain that are responsible for breathing and other basic life functions.4