Brain metastasis symptoms and diagnosis
About 10% to 15% of people with stage IV breast cancer have brain metastases. For most people with metastatic breast cancer that has spread to the brain, the breast cancer has already traveled to another part of the body, such as the bones, lungs, or liver. But for about 17% of people with brain metastasis, the breast cancer has only spread to the brain.
The risk of brain metastasis is usually highest for people with more aggressive subtypes of breast cancer, such as HER2-positive or triple-negative breast cancer.
Symptoms of breast cancer that has spread to the brain can include:
changes in senses controlled by the brain such as slurred speech, blurred vision, balance problems, dizziness, or anything else that seems unusual
mood or personality changes
stroke , which means the blood supply to the brain is cut off; symptoms can include sudden weakness or numbness on one side of the body, headache, trouble speaking, vision changes, dizziness, or loss of balance
Using an MRI scan, often with contrast solution, a doctor can confirm that breast cancer has spread to the brain. Contrast solution is dye that is injected into your arm through an intravenous line. The dye travels to the brain and helps cancerous tissue show up more clearly on the images.
In rare cases, doctors order a biopsy to confirm brain metastasis. To get a tissue sample, a surgeon drills a small hole through the skull. Using MRI or CT scans, a surgeon can guide a narrow, hollow needle into the brain lesion and remove a sample. The surgeon then sends the sample to a pathologist for examination.
Treatment for brain metastasis
Metastatic breast cancer in any part of the body is usually treated with systemic medicines, which treat cancer throughout the entire body. For brain metastasis, local treatments that specifically target the brain, such as surgery or radiation, are sometimes recommended.
Still, treating brain metastases can be challenging because of the blood-brain barrier. The blood-brain barrier is network of blood vessels and tissue that helps keep harmful substances from reaching the brain. The blood-brain barrier lets some things, such as water, oxygen, carbon dioxide, and general anesthetics, pass into the brain. But it also keeps out bacteria and other substances, including many medicines used to treat cancer.
While some chemotherapy medicines can help treat brain metastases, many chemotherapy medicines can't cross the blood-brain barrier. Doctors often combine chemotherapy with targeted therapies, which are medicines that target specific characteristics of cancer cells.
Hormonal therapy medicines — also called endocrine therapy or anti-estrogen therapy — are used to help shrink or slow the growth of hormone receptor-positive metastatic breast cancer. Hormonal therapy medicines include:
Arimidex (chemical name: anastrozole)
Aromasin (chemical name: exemestane)
Femara (chemical name: letrozole)
Faslodex (chemical name: fulvestrant)
Hormonal therapy does not work on hormone receptor-negative breast cancer.
Hormonal therapy medicines treat hormone receptor-positive breast cancers in two ways:
by lowering the amount of the hormone estrogen in the body
by blocking the action of estrogen in the body
Brain metastases are rare with hormone receptor-positive breast cancer so research is limited on how effective hormonal therapy is in these cases. You usually take hormonal therapy to treat metastatic hormone receptor-positive breast cancer for as long as it works. If the cancer stops responding to one hormonal therapy medicine, your doctor will usually recommend a different hormonal therapy medicine.
Targeted therapies are treatments that target specific characteristics of cancer cells, such as a protein that allows the cancer cells to grow in a rapid or abnormal way. Targeted therapies are generally less likely than chemotherapy to harm normal, healthy cells. Some targeted therapies are antibodies that work like the antibodies made naturally by our immune systems. Because of this, they are sometimes called immune-targeted therapies.
The targeted therapy Tukysa (chemical name: tucatinib) in combination with the targeted therapy Herceptin (chemical name: trastuzumab) and the chemotherapy Xeloda (chemical name: capecitabine) has been shown to be especially effective in treating HER2-positive breast cancer that has metastasized to the brain.
Cancer immunotherapy medicines work by helping your immune system work harder or more efficiently to fight cancer cells.
Your immune system is made up of a number of organs, tissues, and cells that work together to protect you from foreign invaders that can cause disease. When a disease- or infection-causing agent, such as a bacterium, virus, or fungus, gets into your body, your immune system reacts and works to kill the invaders. This self-defense system works to keep you from getting sick.
Immunotherapy uses substances — either made naturally by your body or man-made in a lab — to boost the immune system to:
stop or slow cancer cell growth
stop cancer cells from spreading to other parts of the body
be better at killing cancer cells
Local treatments such as surgery and radiation therapy can remove or destroy areas of breast cancer in the brain.
The goals of local treatment depend on your specific situation:
If you have only a few areas of cancer in the brain and nowhere else in the body (oligometastatic disease) and you’re generally in good health, the goal may be to remove all of the cancer so you have no evidence of disease.
If the breast cancer has spread to other places in the body or to different parts of the brain, the goal is to improve symptoms and prevent complications that can come from having growths pushing into critical areas of the brain.
In most cases, doctors will recommend that you continue receiving systemic treatments, such as hormonal therapy, chemotherapy, targeted therapy, or immunotherapy.
Local treatments for brain metastasis include surgery, stereotactic radiosurgery (SRS), whole-brain radiation therapy (WBRT), and swelling and seizure treatment.
Doctors may recommend surgery for brain metastasis if there are one or two lesions that can be safely removed. Surgeons can use MRI scans before surgery to find a tumor’s exact location. They can also use MRI scans to guide them during surgery to remove the tumor.
Depending on the tumor’s location, you may be a candidate for a less invasive form of brain surgery that uses a technique called neuroendoscopy. Instead of opening the skull, a surgeon can operate through a smaller incision using specialized instruments.
Talk with your medical team about the options that are available and best for you.
Doctors may recommend SRS (stereotactic radiosurgery) for people who have one lesion or up to a few lesions. This technique targets high doses of radiation precisely to the areas of cancer while minimizing any exposure to nearby healthy tissue — which is especially important when the brain is involved — and reduces the risk of side effects.
As with SBRT, the areas of cancer are mapped first using imaging scans so the beams can be targeted with great precision. And as with SBRT, you’re more likely to hear SRS described with brand names such as CyberKnife or GammaKnife.
WBRT (whole-brain radiation therapy) delivers radiation treatments to the entire brain over a period of many weeks. Doctors typically recommend WBRT if there are more than a few areas of cancer in the brain. WBRT helps to shrink the tumors and improve symptoms. Doctors may suggest WBRT in place of, or in addition to, stereotactic radiosurgery.
The side effects of WBRT include thought and memory problems, so it’s important to have a conversation with your medical team to weigh the risks and benefits of WBRT for you.
Metastatic breast tumors can lead to pressure and swelling in the brain. Your doctor may prescribe a corticosteroid such as dexamethasone to manage these symptoms.
About one-third of people with brain metastases eventually develop seizures. Seizures can affect different functions such as movement, consciousness, and speech. Your doctor may prescribe an anti-seizure medication such as Dilantin (chemical name: phenytoin), Depakote (chemical name: valproate), or Keppra (chemical name: levetiracetam) to prevent seizures or control their symptoms.
Together with your medical team, you can decide which approach makes the most sense for you.
— Last updated on August 16, 2022, 9:57 PM