When you’re diagnosed with brain cancer, learning as much as you can about it can help you choose the best treatment for you. This guide shows you the basics on the types of brain cancer and how they’re treated.
Where Brain Cancers Start and Spread
A brain tumor is a mass of cells in your brain that isn’t normal. There are two general groups of brain tumors:
- Primary brain tumors start in the brain and tend to stay there.
- Secondary brain tumors are more common. These cancers start somewhere else in your body and travel to the brain. Lung, breast, kidney, colon, and skin cancers are among the most common cancers that spread to your brain.
Some brain tumors contain cancer cells and others don't:
- Benign brain tumors don't have cancer cells. They grow slowly, can often be removed, and rarely spread to the brain tissue around them. They can cause problems if they press on certain areas of the brain. Depending on the part of the brain they’re in, they can be life-threatening.
- Malignant brain tumors have cancer cells. Some grow quickly and others slowly. They can invade healthy brain tissue nearby. Malignant tumors rarely spread beyond your brain or spinal cord.
Grades of Brain Tumors
Tumors are graded by how normal or abnormal the cells look. The doctor will use this measurement to help plan your treatment. The grading also gives you an idea of how fast the tumor may grow and spread.
- Grade 1. The cells look nearly normal and grow slowly. Long-term survival is likely.
- Grade 2. The cells look slightly abnormal and grow slowly. The tumor may spread to nearby tissue and can come back, maybe at a more life-threatening grade.
- Grade 3. The cells look abnormal and are actively growing into nearby brain tissue. These tumors tend to come back.
- Grade 4. The cells look most abnormal and grow and spread quickly.
Some tumors change. Rarely, some benign tumors can turn malignant, and a lower-grade tumor may return at a higher grade.
Types of Brain Tumors
In adults, the most common types of brain cancer are:
- Astrocytomas. These usually form in the largest part of the brain, the cerebrum. They start in a common type of star-shaped cell called an astrocyte. They can be any grade. They often cause seizures or changes in behavior. Astrocytomas usually spread throughout the brain and blend with other tissue. But not all of these tumors behave the same. Some grow quickly, and some grow slowly. Not all of them grow into other tissue.
- Meningiomas. These are the most common primary brain tumors in adults. They’re most likely to happen in your 70s or 80s. They start in the meninges, the lining of the brain. They can be grade 1, 2, or 3. They’re often benign and grow slowly.
- Oligodendrogliomas. These form in the cells that make the covering that protects nerves. They’re usually grade 1, 2, or 3. They usually grow slowly and don't spread.
Less common types of brain cancer include:
- Ependymomas. This rare cancer forms in your brain or spinal cord. It starts in cells that line the ventricles (fluid-filled spaces in the brain) as well as in the canal that holds the spinal cord and cerebrospinal fluid (CSF). They can be fast-growing or slow-growing. If they're fast-growing, they’re called anaplastic ependymoma. These tumors spread along the CSF but don’t spread into normal brain tissue. Nearly half of ependymomas are diagnosed in kids under age 3, but they can also affect adults.
- Mixed gliomas. These are made up of more than one type of cell. They can include oligodendrocytes, astrocytes, and ependymal cells.
- Mixed glial and neuronal tumors. These are made up of glial and neuronal cells. They tend to affect children and young adults. They include ganglioglioma, pleomorphic xanthoastrocytoma (PXA), and a dysembryoplastic neuroepithelial tumor (DNET).
- Primitive neuroectodermal tumors (PNETs) are most common in children, but they can affect adults. They start in immature central nervous cells called neuroectodermal cells. These tumors are more common in younger children than older ones, and they typically grow quickly. The most common PNET is a medulloblastoma, which starts in the cerebellum. Other PNETS include pineoblastomas, which start in the pineal gland. Neuroblastomas start in the brain or spinal cord.
How Brain Cancer Is Treated
Your treatment will depend on the type and grade of the cancer, where it's located, its size, and your age and health.
- Surgery is usually the first treatment. For grade 1 tumors, it may be enough. It’s possible that all the cancer can be removed. But even if it isn’t, the surgery can reduce the size and ease symptoms.
- Radiation therapyis used after surgery to kill any tumor cells that remain in the area. If surgery isn’t an option, you may have only radiation therapy.
- Chemotherapy is sometimes used to kill brain cancer cells. It is given by mouth, IV, or, less often, in wafers a surgeon puts in the brain.
- Targeted therapy can treat certain types of brain tumors. These medicines attack specific parts of cancer cells and help stop tumors from growing and spreading.
- Your doctor may also recommend combined therapies.
If you have cancer, it’s important to follow your treatment plan, work with your doctor, and go to your regularly scheduled appointments.