What is metastatic breast cancer?

Metastatic breast cancer is the most advanced stage of breast cancer. Breast cancer develops when abnormal cells in the breast start to divide uncontrollably. A tumor is a mass or collection of these abnormal cells.

Metastasis refers to cancer cells that have spread to a new area of the body. In metastatic breast cancer, cells may spread to the:

• Bones.
• Brain.
• Liver.
• Lungs.

Healthcare providers name cancer based on its primary origin. That means breast cancer that spreads to other body parts is still considered breast cancer. The cancer cells are still breast cancer cells. Your care team will use breast cancer therapies, even if the cancer cells are in other areas.

What’s the difference between metastatic breast cancer and stage 4 breast cancer?

These two terms mean essentially the same thing. Breast cancer classified as stage 4 has spread outside the breast, or metastasized, to other parts of the body.

When do people get a metastatic breast cancer diagnosis?

Metastatic breast cancer can occur at different points:

• De novo metastatic breast cancer: About 6% of women and 9% of men have metastatic breast cancer when they’re first diagnosed with breast cancer.
• Distant recurrence: Most commonly, metastatic breast cancer is diagnosed after the original breast cancer treatment. A recurrence refers to the cancer coming back and spreading to a different part of the body, which can happen even years after the original diagnosis and treatment.

Who is at risk for metastatic breast cancer?

Some people are at higher risk for metastatic cancer after finishing cancer treatment. The risk depends on various features of the cancer including:

• Tumor characteristics (type of cancer cells).
• Stage at your first diagnosis.
• Treatment(s) received.

How common is metastatic breast cancer?

Around 170,000 people in the United States are living with metastatic breast cancer. Fewer than 1 in 3 women who are diagnosed with early-stage breast cancer later develop metastatic breast cancer.

What causes metastatic breast cancer?

Cancer cells can invade nearby lymph nodes or blood vessels. The cancer cells then travel throughout the body via lymph vessels or blood vessels. These vessels carry fluid and blood throughout the body. Cancer cells may form small tumors in their new locations.

Why does metastatic breast cancer happen?

Most often, metastatic cancer occurs because treatment didn’t destroy all the cancer cells. Sometimes, a few cells remain dormant, or are hidden and undetectable. Then, for reasons providers don’t fully understand, the cells begin to grow and spread again.

De novo metastatic breast cancer means that at the time of initial diagnosis, the breast cancer has already spread to other parts of the body. In the absence of treatment, the cancer spreads.

There is nothing you can do to keep breast cancer from metastasizing. And metastatic breast cancer doesn’t happen because of something you did.

What are the symptoms of metastatic breast cancer?

Your symptoms depend on where cancer cells have invaded:

Symptoms of bone metastases:

• Bone pain.
• Bones that break or fracture more easily.
• Swelling.

Symptoms of brain metastases:

• Worsening headaches or pressure in the head.
• Visual disturbances.
• Seizures.
• Nausea and vomiting.
• Behavior or personality changes.

Symptoms of liver metastases:

• Jaundice.
• Itchy skin or rash.
• Stomach pain, loss of appetite, nausea and vomiting.

Symptoms of lung metastases:

• Cough that won’t go away.
• Difficulty catching your breath.
• Chest pain.

Other symptoms of metastatic breast cancer:

• Fatigue.
• Unexplained weight loss.
• Poor appetite.

Additional signs of metastatic breast cancer can include:

• Liver test showing high enzymes.
• Chest X-ray that shows signs of a problem.

How is metastatic breast cancer diagnosed?

If you have symptoms of metastatic breast cancer, your provider may recommend tests including:

• Blood tests, including complete blood count and comprehensive metabolic panel.
• Imaging studies, including MRI, CT, bone scan and PET.
• Bronchoscopy, which uses a scope to look inside your lungs — this can be done if there is a concerning spot in the lungs.
• Biopsy to remove tissue from a suspicious area and analyze it.
• A “tap” to remove fluid from an area with symptoms. For example, pleural tap removes fluid from the lung area. Spinal tap removes fluid from the spinal cord area.

Can metastatic breast cancer be cured?

There is no cure for metastatic breast cancer. Once the cancer cells have spread to another distant area of the body, it’s impossible to get rid of them all. However, the right treatment plan can help extend your life and improve its quality.

Metastatic breast cancer treatment aims to shrink tumors, slow their growth and improve your symptoms.

How is metastatic breast cancer treated?

The main treatment for metastatic breast cancer is systemic therapy. These therapies treat the entire body. Systemic treatments may include a combination of:

• Chemotherapy.
• Hormonal therapy.
• Immunotherapy.
• Targeted therapy.

Your care team will plan your treatment based on:

• Body parts cancer has reached.
• Past breast cancer treatments.
• Symptoms.
• Tumor biology, or how the cancer cells look and behave.

Why does my provider need to test the metastatic tumor?

Your care team will test the metastases to figure out the biology of the tumor, which can help guide your treatment plan. Providers may test tumors for:

• Hormone receptor (estrogen and progesterone) status: If the cancer is hormone receptor-positive, hormonal therapy may be your first treatment.
• HER2 status: Human epidermal growth factor receptor 2 is a protein that is overexpressed on some breast cancer cells. HER2-positive cancer responds to specific HER2-targeted therapies.
• PIK3CA gene mutation: If a tumor is hormone receptor-positive and HER2-negative, your provider may test for this gene mutation. Specific targeted therapies can be used to treat tumors with this mutation.
• PD-L1 status: Tumors that are hormone receptive-negative and HER2-negative may be tested for PD-L1 status. If the PD-L1 test is positive, you may be recommended to receive a combination of immunotherapy and chemotherapy.

How long will treatment for metastatic breast cancer last?

Essentially, treatment for metastatic breast cancer continues indefinitely. You may also decide to stop treatment if you can’t or don’t wish to tolerate the side effects. Cancer treatment side effects can be uncomfortable.

Will I need more than one treatment for metastatic breast cancer?

Medications are important for metastatic breast cancer to help control its spread. Resistance to therapies may develop, which can lead your care team to recommend a change in treatment.

When you start a treatment regimen, you and your care team will see how:

• The cancer responds to the therapy.
• The side effects impact you.

If the treatment isn’t working or the side effects are unbearable, your care team can discuss switching the treatment method. They may recommend a different drug, dosage or schedule.

There are many treatments available. If one therapy isn’t working for you for whatever reason, there is usually another one you can try.

Will I need surgery for metastatic breast cancer?

Healthcare providers usually don’t recommend breast cancer surgery for metastatic breast cancer. Surgery is unlikely to help if cancer has spread to more than one location in the body.

In some cases, surgery may help:

• Prevent broken bones.
• Relieve blockages in your liver.
• Ease pain.

Will I need radiation therapy for metastatic breast cancer?

Radiation therapy is not a typical treatment for metastatic breast cancer. But your provider may recommend radiation therapy for specific situations. For example, radiation therapy can help ease pain or control cancer growth in a specific area.

Can metastatic breast cancer be prevented?

There are currently no proven ways to prevent metastatic breast cancer. But researchers are working on treatments that may prevent cancer from spreading and coming back (recurring).

How can I reduce my risk of getting breast cancer?

The earlier breast cancer is diagnosed, the more effective treatment can be. When cancer is diagnosed and treated at an earlier stage, the outlook is typically better. Talk to your provider about when you should start having regular breast exams and mammograms.

What’s the outlook for metastatic breast cancer?

The right treatment plan can improve survival for people with metastatic breast cancer. However, survival rates vary and are dependent on a number of factors including type/biology of the breast cancer, parts of the body involved and individual characteristics. About 1 in 3 women live at least five years after diagnosis. Some live 10 years or longer. Your care team will discuss your prognosis with you in more detail.

How can I take care of myself while living with metastatic breast cancer?

Living with metastatic breast cancer can be challenging. Your care team can help provide physical and emotional support. Talk to them about how you can:

• Eat the most nutritious diet for your needs.
• Exercise regularly.
• Manage stress.
• Get emotional support, including finding support groups.
• Reach out for help from friends, family and loved ones.
• Find mental health services.
• Find complementary therapies.

What can I expect while living with metastatic breast cancer?

Your care team will monitor you every few months to check if the cancer is responding to treatment, and also to see if you are having any side effects. The process of “restaging” the cancer includes:

• History/physical exam.
• Blood tests.
• Imaging tests, including CTs and bone scan or PET scan.

Before your scans or tests, it’s normal to feel anxiety. It may help to bring a friend or family member to the appointment with you.

Can metastatic breast cancer go into remission?

Metastatic breast cancer may never go away completely. But treatment can control its spread. Cancer may even go into remission at some points. This means you have fewer signs and symptoms of cancer.

A treatment break may be considered in certain situations, including if remission occurs or if someone is experiencing intolerable side effects. A pause in treatment can help you feel your best and improve your quality of life.

What if I decide to stop treatment for metastatic breast cancer?

Receiving or stopping treatment is up to you. Your care team can help you think about and plan for this next stage.

You may want to consider how to:

• Manage symptoms.
• Organize your finances.
• Choose a hospice program.
• Have difficult conversations with family and loved ones.

What should I ask my healthcare provider about metastatic breast cancer?

If you’ve been diagnosed with metastatic breast cancer, ask your provider:

• What are my treatment options?
• What is my prognosis?
• What side effects can I expect?
• Will complementary therapy help me feel better?
• What if I want to stop treatment?
• How can I feel my best during treatment?

A note from Cleveland Clinic

Metastatic breast cancer is advanced breast cancer. Providers classify it as stage 4 breast cancer. It happens when cancer cells, often left behind after previous breast cancer treatment, start to spread to other parts of the body. While there is no cure for metastatic breast cancer, treatment can prolong your life and help you feel better. There are many medications available, so if one treatment isn’t working, your care team can try a different approach. If you notice any symptoms or don’t feel your best, especially if you’ve undergone breast cancer treatment in the past, talk to your healthcare provider.