Sometimes tumors growing in the brain begin there. These are called primary brain tumors. But other types of brain tumors begin as cancers somewhere else in the body. These can start in the lung, breast, skin, kidney, colon, or other body parts. They may spread to the brain if the cancers are not controlled at the original site. These are called secondary or metastatic brain tumors.
In adults, metastatic brain tumors are more common than tumors that begin in the brain, and are treated differently from those that start in the brain.
Facts about metastatic brain tumors
Cancer may spread to the brain through your lymph system or your bloodstream. Or it may travel to the brain from a nearby tissue. Metastatic brain tumors are becoming more common because people are living longer after having cancer somewhere else in their body.
In most cases, the metastatic brain tumor is found in the cerebrum. This is the outer part of the brain that controls your thoughts, emotions, and language ability. It also is involved in movement and sensing the outside world. But these tumors can appear elsewhere in the brain, too.
Metastatic brain tumors happen most commonly in lung cancer, but can occur in many other types.
Symptoms of this condition can vary, depending on the size and number of tumors in the brain and where they occur. These are possible symptoms:
Changes in personality
Loss of feeling or movement on one side of the body, typically in the arm or leg
Sometimes, your doctor will know if you already have a cancer somewhere else in your body. But in some cases, the doctor finds the metastatic brain tumor first. Doctors may diagnose this condition using:
MRI, CT, or PET scan. These are different ways of painlessly creating an image of your brain for the doctor to see. A PET scan is commonly performed to determine whether there are any other areas on the body with cancer.
Cerebral angiography. During this test, dye will be injected through a tube put into a blood vessel. Then the doctor will take X-rays of your brain. The dye shows the path of the blood flow in your brain, which may help show if a tumor is in your brain. This test is not used much anymore and has largely been replaced with MRI and CT angiography.
Spinal tap. Also called a lumbar puncture, this test looks for cancer cells in the fluid found around your brain and spinal cord.
Other tests. Your doctor may do scans of other parts of your body to look for the camcer that led to brain tumor. A doctor may also remove part of the tumor in your brain or the rest of your body to examine it.
A surgeon may be able to remove the tumor during brain surgery. In some cases, the surgeon may only be able to remove part of it. When more than one metastatic brain tumor occurs in the brain, surgical treatment may not always be an option. Other types of surgery may help relieve pressure on the brain and treat symptoms if the tumor can't be removed.
Doctors may be able to treat the brain tumor with radiation. Radiation therapy may involve radiation of the whole brain or more focused radiation treatment (such as with the gamma knife). Chemotherapy may also be an option. In addition, the doctor may provide medicines that relieve swelling in the brain, reduce the number of seizures, and relieve pain.
You can take a number of steps to reduce your risk for cancers that can spread to your brain:
Eat a healthy diet.
Get regular exercise.
Maintain a healthy weight.
Limit your sun exposure.
Have regular screening exams for certain cancers, such as mammograms for breast cancer.
Managing brain tumors
Sometimes, doctors won’t be able to cure this disease. In some cases, they will suggest methods to keep a person comfortable during his or her remaining time. These may include specific treatments and medicine to reduce pain and other symptoms.