When a metastatic brain tumor is diagnosed, it means that cancer cells from another organ have spread to the brain.
Metastatic tumors are the most common type of brain cancer today—about 10 times more common than cancers that originate within the brain (such as gliomas or meningiomas). The prevalence of brain metastases is increasing because cancer treatment has advanced considerably; instead of living just months after cancer diagnosis, many people live years with the disease, or their cancers go into remission. An estimated 200,000 new cases of brain metastases are now diagnosed in the U.S. every year.
Just a decade ago, finding a brain metastasis meant a person's average life expectancy was no more than six months, making aggressive treatment not worthwhile. That's no longer the case. With longer survival rates, neurosurgery is increasingly used to treat brain metastases.
Our dedicated team of oncologists and neurosurgeons focus specifically on the management of brain metastases. At Yale Medicine our world-renowned experts use state-of-the-art equipment to provide patients the best possible multidisciplinary care.
What is a metastatic brain tumor?
When a metastatic brain tumor is diagnosed, it means that cancer cells from another organ have spread to the brain. Twenty to 40 percent of patients who have a cancer that has spread in the body will also develop cancer in the brain. The cells that form metastatic brain tumors can originate from any organ, but most often they come from lung, breast, skin, ovarian and intestinal cancers.
Metastatic tumors are the most common type of brain cancer today. Being diagnosed with a brain metastasis used to mean your life expectancy was six months or less, but that's no longer true. With longer survival rates due to a variety of more effective treatments, neurosurgeons are now closely involved in treating metastatic brain cancer.
What are the symptoms of metastatic brain tumors?
Unlike 10 years ago, many patients today experience no symptoms from brain metastases. That's because, as part of their cancer care they regularly undergo imaging scans of the brain (just like regular CT scans for the body) and most metastases are found when they are still too small to cause symptoms.
However, in some cases where a tumor has had time to enlarge and press against other parts of the brain, symptoms such as these may begin:
- Daily, constant headaches that become worse and more frequent over time, associated with vomiting or changes in vision
- Weakness or numbness only on one side of the body
- Clumsiness, trouble walking, or decreased coordination
- Difficulty with speech comprehension or expression
- Emotional or personality changes
How are metastatic brain tumors diagnosed?
Brain tumors are usually detected with an imaging test, typically computed tomography (CT) scans and magnetic resonance imaging (MRI) scans. Positron emission tomography (PET) scans, which use a radioactive substance called a tracer to search for disease, can also detect tumors when they become large, but these scans are much less sensitive and should not be relied upon for looking for brain metastases.
If a tumor is found in the brain on CT or MRI and there is no pre-existing diagnosis of cancer, the doctors will typically get scans of the rest of the body to determine if the cancer came from outside the brain. If a source is found in the body, then a biopsy can be obtained from there rather than from the brain, and the brain tumor can be presumed to be related to the cancer found in the body.
If the only tumor found is the one in the brain, a biopsy in the brain may be required to determine whether it is cancer and, if so, where it originated.
What are the risk factors of metastatic brain tumors?
One of the most formidable challenges of cancer research is that doctors still don’t know why some people develop cancer and some do not. Even less well understood is why some cancers spread to the brain and other do not. What is known, however, is that brain metastases can occur in any long-term cancer survivor.
In addition, certain cancers as melanoma, or some subsets of other cancers—such as EGFR-mutant lung cancer and Her2 positive breast cancer—also seem to be more likely to spread to the brain.
Patients with these cancer types should undergo brain scans on a regular basis to look for cancer spread to the brain before it causes neurological problems.
How are metastatic brain tumors treated?
Treating a brain tumor is usually only one step in treating metastatic cancer. At Yale Medicine, treatment is carefully coordinated among the neurosurgery, radiation oncology and medical oncology teams.
Traditionally, treatment for brain metastases involves radiation and surgery, since chemotherapy has limited ability to penetrate into the brain.
Patients whose brain scans reveal only a few metastases can be considered for a targeted radiation treatment called radiosurgery. At Yale Medicine, this treatment is delivered using a machine known as the Gamma Knife. If this procedure is appropriate, then imaging required for treatment, treatment planning and radiation delivery can all be done in one day. This has the advantage of minimizing interruption of chemotherapy.
For those with larger or more widespread brain tumors, Yale Medicine also offers the more comprehensive treatment options, including:
- Hippocampal sparing whole brain radiation therapy with memantine
- Surgical resection or laser ablation - guided by use of MRI in the operating room
- Microsurgical resection of tumor
Lastly, for select patients, clinical trials are available for the treatment of newly diagnosed brain metastases using chemotherapy alone. At this time, this option is available for patients with lung and melanoma brain metastases.
What is recovery like?
Even if they come in with neurological problems due to their brain metastases, many patients today make full recoveries - especially if their metastases are caught early.
"It's nice to be able to offer relief and say that, in fact, the cancer in the brain is really not the determinant of a patient's survival," says Dr. Chiang.
What makes Yale Medicine's approach to treating metastatic brain tumors unique?
Yale Medicine is leading the way nationally in the use of the newer chemotherapy agents, including immunotherapy and targeted therapies.
For example, Yale Medicine offers a unique clinical trial evaluating the use of immunotherapy alone, and deferring radiation, to treat brain metastases. Data showing preliminary success was recently published in Lancet Oncology.
Yale Medicine is the only multidisciplinary consortium providing comprehensive brain cancer care in southern New England. This gives patients access to the full range of treatment options, from medical therapy to cutting-edge radiosurgery.
At Yale Medicine, treatment is not suggested based on the technology we own, but rather is personalized to the patient's needs and evidence-based, acquired through national research and experience. Discussion of challenging cases, both from within our Yale Cancer Centeras well as referred to Yale Medicine from other centers around the state, occurs at a weekly tumor board. Recommendations from the Tumor Board are then communicated back to the involved physicians to ensure seamless coordination of care.