What are Brain Metastases?
A brain metastasis is different from brain cancer in that it is a tumor that originates from a primary tumor in another part of the body and not the brain. Most brain metastases arise from lung, breast, and colorectal cancer as well as melanoma, and renal cell carcinoma. For example, brain metastases from lung cancer occur when cancer cells break off from the tumor in the lungs and then enter the bloodstream or travel through the lymph system to the brain, where they multiply.What Causes Brain Metastases?
Brain metastases are caused by tumor cells from cancer somewhere else in the body spreading through the blood and then to the brain. Lung cancer is one of the cancers most likely to spread to the brain. Approximately 10% of patients with non-small-cell lung cancer (NSCLC) have brain metastases at their initial diagnosis, while up to 40% of patients with this cancer will eventually develop brain tumors during their illness.Symptoms
Unfortunately, as brain metastases is linked to small cell lung cancer which in itself is often difficult to diagnose in the early stages, the primary cancer may have already spread to the brain before a lung cancer diagnosis is even made. As it can be easy to miss small growths, patients with lung cancer must watch for symptoms of brain metastases. These can range from no symptoms at all to severe neurological problems, but the most common symptoms to watch out for typically include:
- Nausea or vomiting
- Blurred vision
- Balance problems
- Loss of sensation or weakness along one side of the body
- Difficulty walking
- Loss of coordination (such as reaching for a door handle and missing)
- Speech problems
- Cognitive problems or memory loss
- Personality or behavior changes
Brain metastases are usually diagnosed via magnetic resonance imaging (MRI). If there are multiple tumors seen on an MRI, this suggests that a tumor somewhere else in the body has spread to the brain. Doctors of lung cancer patients will order imaging tests if they suspect that the cancer has spread to the brain.Treatment Options
As is often highlighted with all types of cancer, early detection saves lives. Thus, if diagnosed and treated early, brain metastases usually do respond to therapy. Treatment for brain metastases depends largely on the following factors:
- size and number of tumors
- location of the tumors in the brain
- genetic characteristics of the metastases
- the extent of disease outside the brain
- overall health of the patient
Today, there are several treatment options available for brain metastases and while these treatments are not considered possible cures, they do aim to reduce pain and increase how long you live with lung cancer that has spread to the brain. These treatments can make a significant difference in quality of lives for patients with brain metastases.
Surgery is an option for people with only one or two brain metastases that are easily accessible and uncomplicated or patients with a larger tumor that is causing compressive symptoms. Surgery could involve either complete or partial removal of a tumor to help alleviate symptoms and may be followed by whole-brain radiation.
Radiation therapy is another option and involves the use of X-rays or other high-energy beams to kill cancer cells, and different methods of radiation are used to treat brain metastases.
Another type of treatment is targeted therapy which can identify and attack specific cancer cells with minimal harm to normal cells. Targeted drugs for specific genetic mutations are sometimes able to penetrate the blood-brain barrier with some of the newer drugs showing encouraging signs of being effective at treating brain metastases.
In general, chemotherapy is not effective in treating brain metastases due to the presence of the blood-brain barrier, that serves to keep toxins (including chemotherapy drugs) out of the brain. However, chemotherapy may reduce the size of tumors in the lungs thus limiting their ability to spread to the brain.Spreading Awareness
Early detection is the best tool at diagnosing brain metastases. Because most metastatic brain tumors arise from existing lung and breast cancers and melanoma, it is important to treat those primary cancers as this will reduce the chance of developing brain metastases. Being aware of your risk for developing brain metastases is another step towards prevention so speak to your healthcare provider about your individual risk for developing metastatic brain tumors.
The most important thing to remember is that it is not all doom and gloom. Research as well as new drugs/ treatment options have been extremely encouraging and have shown positive results. 10 years ago, people diagnosed with a brain metastasis survived, on average, less than 6 months. Whereas these days, new treatments have emerged allowing people with brain metastases to live longer than ever before.
Click the link below to learn more on Gamma Knife Surgery, which is one of the recommended treatment for brain metastasis.