Unlike brain cancer, which originates in the brain and consists of brain cancer cells, brain metastases from lung cancer occur when cancer cells break off from the tumor in the lungs and enter the bloodstream or travel through the lymph system to the brain, where they multiply, according to Mayo Clinic. While metastatic lung cancer can rarely be cured, improvements in the detection and treatment of brain metastases are allowing people to live longer, with a higher quality of life. Standard treatments, such as surgery and radiation, for brain metastases have gotten better and more precise. And the last few years have also brought newer, systemic therapies that can target these brain tumors in many people.
Recognizing the Signs of Brain Metastases
As metastatic brain tumors grow, they can directly damage cells or affect the brain indirectly by compressing parts of it or causing swelling and increased pressure within the skull. Early warning signs can be subtle and easily attributed to other causes, including chemotherapy, says Jonathan Goldman, MD, an associate professor of hematology and oncology at Jonsson Comprehensive Cancer Center at the University of California in Los Angeles. Symptoms vary depending on where the metastases are in the brain but often include:
HeadachesFatigueNausea or vomitingSeizuresBlurred visionBalance problemsLoss of sensation or weakness along one side of the bodyDifficulty walkingLoss of coordination (such as reaching for a door handle and missing)Speech problemsCognitive problems or memory lossPersonality or behavior changes
If you consistently experience any of these symptoms, it’s important to alert your cancer care team as soon as possible. To diagnose brain metastases, your doctor will most likely perform a neurological exam (which may include checking your vision, hearing, balance, coordination, strength, and reflexes) and order a magnetic resonance imaging (MRI) scan of your head. An MRI can not only detect cancer but also precisely identify the location and size of each brain lesion. Other imaging tests your doctor may use include positron emission tomography (PET) and computerized tomography (CT) scans. A biopsy, where brain tumor tissue is removed either as part of surgery to remove the tumor or during a procedure in which a small sample is taken with a needle, may also be done to confirm a diagnosis and help determine the best course of treatment. The tissue is then viewed under a microscope to determine whether it’s cancerous; if it is, the biopsy can also determine if it’s a primary or metastatic tumor. Surgery Surgery may be an option for people with only one or two brain metastases that are easy to access and remove or a larger tumor that’s causing compressive symptoms, according to Johns Hopkins Medicine. It may involve complete or partial removal of a tumor to help alleviate symptoms and is typically followed by whole-brain radiation. Radiation This therapy 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. People with fewer than five lung cancer metastases in the brain may be good candidates for stereotactic radiation, in which advanced imaging and computer guidance are used to deliver large doses of radiation directly to tumors. “This approach can effectively treat metastases with little radiation exposure to other parts of the brain and with minimal side effects,” says Dr. Goldman. If you have many tumors throughout your brain or a large tumor deep in the brain, your doctor may recommend whole-brain radiation, in which radiation is applied to the entire brain to kill tumor cells. “This method,” Goldman explains, “treats the whole area but unfortunately comes with more side effects, such as headache, fatigue, nausea, hair loss, and some slowed cognition.” Systemic therapy With systemic therapies, including chemotherapy, targeted therapy, and immunotherapy, drugs travel through the bloodstream to reach cancer cells throughout the body. Because many chemotherapy drugs are unable to cross the blood-brain barrier — a network of capillaries that keeps certain substances from reaching the brain — targeted therapy is the primary form used to treat brain metastases. Targeted therapies can identify and attack specific cancer cells with minimal harm to normal cells. For people with lung cancer cells that have specific mutations (such as EGFR and ALK), these therapies can be highly effective. But if your lung cancer doesn’t carry these specific mutations or has metastasized elsewhere in the body, other systemic therapies, such as immunotherapy (which uses medicine to activate your own immune system to recognize and kill cancer cells) and chemotherapy, may be considered. Palliative care This type of specialized medical care, which can include physical therapy, relaxation techniques, exercise, speech therapy, and pain management, is also a key component of treatment for patients with metastatic NSCLC. These complementary approaches can help mitigate the side effects of both the cancer and its treatment and significantly improve quality of life. Information and support for people with lung cancer and their families is available at the Go2 Foundation for Lung Cancer, the American Cancer Society, and the Global Resource for Advancing Cancer Education (GRACE).
Looking Ahead: After Brain Metastases Treatment
After surgery, radiation, or systemic treatment for brain metastases, your doctor will most likely order an MRI to determine how much of the tumor is gone and then continue to follow up every few months with another MRI. The prognosis for people with NSCLC that’s metastasized to the brain is highly variable, so it’s important to keep in mind that statistics don’t necessarily pertain to your situation. While the outlook was poor for people with NSCLC and brain metastases traditionally, advancements in treatment are continually improving survival rates. Clinical trials are regularly being conducted to find ways to improve treatment for people with NSCLC that’s metastasized to the brain; ask your doctor whether you may be a candidate for such a trial. You can also search for a clinical trial in your area at ClinicalTrials.gov. “Brain metastasis has traditionally been an area that was difficult to study,” Goldman notes, “but thankfully, more and more studies are focused on exactly this problem.” Additional reporting by Erica Patino
