What Is Breast Cancer With Brain Metastasis?

What Is Breast Cancer With Brain Metastasis?
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Published on June 12, 2024
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A diagnosis of metastatic breast cancer, also known as stage 4 breast cancer, means the cancer has spread beyond the breast to other parts of the body. In up to 15 percent of people with stage 4 breast cancer, the cancer spreads to the brain.

 The rate of brain metastasis can be as high as 50 percent in people who have more aggressive types of breast cancer, such as triple-negative and HER2-positive breast cancer.

Usually, metastatic breast cancer first spreads to organs like the lungs, liver, or bone before it reaches the brain. Less often, the brain is the first place where advanced breast cancer travels.

When breast cancer is in the brain, doctors don’t call it brain cancer. They call it metastatic breast cancer in the brain or secondary breast cancer in the brain, and it’s treated the same way as other breast cancers.

Once breast cancer becomes metastatic, it’s no longer considered curable. But treatments can slow its progression and improve quality of life for many people with this disease.

Title: Symptoms of Breast Cancer With Brain Metastasis. Headache, memory problems, blurred or double vision, stroke, slurred speech, dizzness and balance problems, nausea and vomiting, numbness or tingling, weakness on one side of body, seizures.
Breast cancer that has spread to the brain can cause any or all of these symptoms.

Symptoms of Breast Cancer Metastasis to the Brain

Symptoms of breast cancer that has spread to the brain include:

  • Blurred vision, double vision, or other vision changes
  • Dizziness and balance problems
  • Headache
  • Memory problems
  • Mood, personality, or behavior changes
  • Nausea and vomiting
  • Numbness or tingling
  • Seizures
  • Slurred speech
  • Stroke
  • Weakness on one side of the body

Causes and Risk Factors for Breast Cancer Metastasis to the Brain

Breast cancer spreads when cancer cells break away from the original tumor in the breast and travel through the bloodstream or lymphatic system. From there, the cancer can reach other organs.

The brain is a difficult organ to access because it’s “guarded” by a wall called the blood-brain barrier (BBB) that protects it from toxic substances. Breast cancer cells must adapt so they can cross this barrier and survive in the brain.

Once inside the brain, the cancer is able to multiply. In part this is because areas of the brain like the hippocampus, hypothalamus, and amygdala contain the hormone estrogen. Estrogen helps breast cancer cells grow.

Women who were diagnosed with breast cancer before age 35 have a higher risk of brain metastasis. The risk is also higher for people who have:

  • An aggressive type, such as triple-negative or HER2-positive breast cancer
  • A higher-grade tumor, which means that it grows quickly
  • A tumor that is larger than 2 centimeters in diameter at diagnosis
  • Cancer that is in the lymph nodes at diagnosis
These risk factors don't mean the cancer will definitely spread to the brain. Many people who have these risk factors don’t develop brain metastasis.

Diagnosing Breast Cancer Metastasis to the Brain

If you have symptoms of brain metastasis or your doctor thinks your cancer has spread to your brain, you will have a test called magnetic resonance imaging (MRI). This test uses a powerful magnet and radio waves to produce detailed pictures of the brain. An injection of contrast dye makes the cancer show up more clearly on the MRI.

Computed tomography (CT) is the alternative when an MRI can’t be done. This test uses X-rays to create detailed cross-sectional images of the brain.

If the diagnosis isn’t clear, the doctor might do a biopsy. This involves drilling a small hole in the skull and inserting a thin needle to remove a small tissue sample from the brain. That sample then goes to a lab for testing.

Treatments for Breast Cancer Metastasis to the Brain

Doctors usually treat metastatic breast cancer with systemic therapies — ones that kill cancer throughout the body. But brain metastasis is challenging because it can be hard for medicine to get through the blood-brain barrier.

The main treatment options for breast cancer with metastasis to the brain are targeted therapy, hormone therapy, chemotherapy, surgery, radiosurgery, and radiation therapy.

Targeted Therapy

These treatments target certain proteins or other features of the cancer cells that help them grow. A combination of the targeted drugs tucatinib (Tukysa) and trastuzumab (Herceptin) plus the chemotherapy drug capecitabine (Xeloda) has been shown to be an effective treatment for HER2-positive metastatic breast cancer with brain metastasis in people whose cancer can’t be removed by surgery and who have already tried other treatments.

Tucatinib and capecitabine are taken by mouth, and trastuzumab is given through an IV.

Possible side effects of this drug combination include:

  • Anemia
  • Cough
  • Diarrhea
  • Fever or chills
  • Hand-foot syndrome (redness and blistering in the palms of the hands and soles of the feet)
  • Headache
  • Heart problems

  • Infection
  • Liver or kidney problems

  • Rash
  • Reduced appetite
  • Sleeplessness
  • Swelling of the mouth and lips
  • Vomiting

Trastuzumab-emtansine (Kadcyla) is a newer type of targeted therapy called an antibody-drug conjugate. It attaches to the cancer cell and delivers chemotherapy directly to it. Trastuzumab-emtansine is approved for people with HER2-positive metastatic breast cancer who are no longer responding to trastuzumab and chemotherapy. It’s an IV infusion given once every three weeks.

Some of the most common side effects are:

  • Bleeding, including nosebleeds
  • Constipation
  • Fatigue
  • Headache
  • Low platelets
  • Muscle and joint pain
  • Nausea

Hormone Therapy

This treatment lowers estrogen levels or blocks the actions of estrogen to prevent it from helping breast cancer grow. Hormone therapy only works for hormone receptor (HR)–positive breast cancers. For HR-positive breast cancer with brain metastasis, it’s only used in patients who have never received hormone therapy before for breast cancer.

Brain metastasis is rare with HR-positive breast cancer, so more research is needed to know how well hormone therapy works in these cases.

 Doctors often combine hormone therapy with targeted therapy to improve the effectiveness.

Examples of hormone therapy drugs are:

  • anastrozole (Arimidex)
  • exemestane (Aromasin)
  • fulvestrant (Faslodex)
  • letrozole (Femara)
  • tamoxifen (Nolvadex)
Most of these medicines are tablets taken once a day.

The exception is fulvestrant, which comes as an injection given three times in the first month, and then once a month.

Because hormone therapy blocks estrogen, it can cause menopause-like side effects such as:

  • Bone weakness
  • Depression
  • Fatigue
  • Headache
  • Hot flashes
  • Nausea and vomiting
  • Sweating
  • Trouble sleeping

Chemotherapy

These strong medicines kill cancer cells or stop them from dividing. Many chemotherapy drugs can’t cross the blood-brain barrier, but capecitabine, methotrexate (Trexall), and fluorouracil (Adrucil) are among the few drugs that do cross this barrier.

Some chemotherapy drugs come as pills. Others are given through a vein. Doctors often prescribe two or more chemotherapy drugs together or add chemotherapy to targeted therapy for metastatic breast cancer.

Chemotherapy doesn’t work very well against brain metastasis. This treatment is often reserved for people with brain metastasis who’ve already tried hormone therapy and targeted therapy drugs with limited results.

Surgery

Surgery may be an option for people who only have a few areas of cancer in their brain, and whose tumors can be removed safely. Surgery can also be done to relieve symptoms. The surgeon will use MRI to find the tumor during the procedure.

Your surgeon will weigh the risks of side effects like thinking and memory problems against the benefits of having surgery. Radiation therapy is often given after surgery to kill any cancer cells that might have been left behind.

Stereotactic Radiosurgery

Stereotactic radiosurgery is the preferred treatment for people who only have a few areas of cancer (usually one to four) in their brain. This treatment delivers a high dose of radiation directly to the cancer. Aiming the radiation more precisely minimizes damage to healthy tissue and reduces side effects. This treatment may be given on its own, or before or after surgery.

Radiation Therapy

Whole-brain radiation therapy delivers radiation to the entire brain. This may be an option for people who have many areas of cancer in their brain, and for those who aren’t able to have stereotactic radiosurgery. Whole-brain radiation therapy shrinks tumors and relieves symptoms, but it can cause side effects like thinking and memory problems.

 A newer type of whole-brain radiation therapy aims the radiation more precisely to avoid the hippocampus, an area of the brain that’s important for memory.

Clinical Trials

Conducting clinical trials is how researchers investigate new treatments for metastatic breast cancer. Enrolling in one of these studies could give you the chance to try a new therapy that might work better than the ones currently available.

You don’t have to wait until you’ve run out of treatment options to join a clinical trial. Ask the doctor who treats your cancer if any available studies might be a good fit for you.

Prognosis for Breast Cancer With Metastasis to the Brain

When breast cancer spreads to the brain, it typically has a worse prognosis than breast cancer that has spread to other locations like the bone or liver.

 But thanks to new treatments, the outlook is improving.

The average survival time for breast cancer with brain metastasis is around two years, but the prognosis can vary by age, tumor type, and response to treatment.

Your survival time may be longer if:

  • You have HER2-positive breast cancer.
  • You're younger than 60.
  • Only a few areas of the brain are affected.
  • You're generally fit.
  • There's no cancer in the tissue lining the brain and spinal cord (leptomeningeal metastases).

Remember that everyone with metastatic breast cancer is different. General survival rates can’t predict what will happen to you. Your oncologist can give you a better idea of your outlook, and which treatments have the greatest likelihood of improving it.

The Takeaway

Once breast cancer spreads to the brain, it’s no longer considered curable, but there are treatments available to lengthen your survival and reduce symptoms. The treatment your doctor recommends will depend on many factors, including the type of breast cancer you have and which, if any, therapies you’ve already tried in the past. Talk with your doctor about all your available treatment options and best next steps.

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Lisa D. Curcio, MD, FACS

Medical Reviewer
Castle Connolly Top Doctor
Lisa Curcio, MD, is a board-certified general surgeon and a fellowship-trained surgical oncologist. She is currently the medical director of breast surgery at Northern Dutchess Hospital in Rhinebeck, New York. Dr. Curcio attended George Washington University Medical School in Washington, D.C., where she also completed a residency in general surgery. She was invited to fellowship training in cancer surgery at City of Hope National Medical Center in Duarte, California. She was the recipient of the competitive U.S. Air Force Health Professions Scholarship Program. During her military commitment, Dr. Curcio served in the military as chief surgical oncologist at Keesler Medical Center in Biloxi, Mississippi. 

From 2003 to 2004, she served as program director for Susan G. Komen in Orange County and remains involved with Komen outreach efforts. She was on the board of Kids Konnected, a nonprofit that helps children of cancer patients deal with the emotional fallout of a cancer diagnosis. Currently, she is on the board at Miles of Hope Breast Cancer Foundation, an organization dedicated to providing support services for people affected by breast cancer in New York's Hudson Valley. Dr. Curcio also has a strong background in breast cancer research, having contributed to dozens of peer-reviewed articles. She is currently a member of the Alpha Investigational Review Board.

Her practice includes benign and malignant breast diagnoses. Dr. Curcio was diagnosed with breast cancer at the age of 37. Although her fellowship training was in surgical oncology, this experience motivated her to provide compassionate, high level breast care and to focus on breast surgery.

Dr. Curcio is passionate about treating the patient and individualizing the care plan to their specific needs. Dr. Curcio strongly believes that cancer care must include lifestyle changes to focus on healthier habits to reduce future events. Her practice also focuses on breast cancer risk reduction, education, and access to genetic testing for patients with a family history of breast cancer.
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Stephanie Watson

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Stephanie Watson is a freelance health writer who has contributed to WebMD, AARP.org, BabyCenter, Forbes Health, Fortune Well, Time, Self, Arthritis Today, Greatist, Healthgrades, and HealthCentral. Previously, she was the executive editor of Harvard Women’s Health Watch and Mount Sinai’s Focus on Healthy Aging. She has also written more than 30 young adult books on subjects ranging from celebrity biographies to brain injuries in football.
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