Metastatic Breast Cancer

When breast cancer recurs, or returns, to another part of the body months or years after the initial breast cancer diagnosis and treatment (also referred to as distant recurrence), it is called metastatic breast cancer. When the first diagnosis of breast cancer is metastatic, it is called de novo metastatic breast cancer. This typically means that the cancer has already spread out of the breast and into other areas of the body by the time the initial diagnosis of breast cancer is made.

Invasive ductal carcinoma (IDC) makes up 85% of breast cancer cases. The most common distant areas for invasive ductal breast cancer to spread to are the bones, lungs, liver, and brain. Another type of breast cancer, invasive lobular carcinoma (ILC), makes up about 12% of breast cancers. When ILC spreads, it usually travels to different organs, primarily the uterus, ovaries, stomach, intestines, and sometimes brain.

There is currently no cure available for metastatic breast cancer, but more and more women are living longer with the disease by managing it as a chronic illness with a focus on quality of life as a primary goal. The focus of treatment is to control the disease through continuous treatment and monitoring.

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Table of Contents

Click on the following links to jump to additional information about metastatic breast cancer.

Metastatic breast cancer facts & statistics
How does breast cancer spread, or metastasize?
What are the symptoms of metastatic breast cancer?
Metastatic breast cancer in the bones
Metastatic breast cancer in the lungs
Metastatic breast cancer in the liver
Metastatic breast cancer in the brain
How is metastatic breast cancer diagnosed?
Metastatic breast cancer treatment
Metastatic breast cancer prognosis
Metastatic breast cancer survival rate
Metastatic breast cancer and genetic mutations
Metastatic breast cancer FAQs
Metastatic breast cancer stories of hope

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Metastatic breast cancer facts & statistics

• An estimated 168,000 women in the United States are living with metastatic breast cancer.¹
• The 5-year survival rate for women with metastatic breast cancer is increasing, especially among women ages 15-39.²
• Approximately one-third of women with metastatic breast cancer have lived with the disease for 5 or more years.³
• Some women may live for 10 years or longer with metastatic breast cancer.⁴
• Approximately 85% of patients diagnosed with MBC have had an early-stage breast cancer diagnosis, though most patients with early-stage breast cancer do not go on to develop MBC.⁵
• Nearly 30% of women initially diagnosed with early-stage breast cancer will ultimately develop metastatic breast cancer.⁶
• While rare, men can also develop metastatic breast cancer.⁷

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How does breast cancer spread, or metastasize?

The spread of cancer (metastasis) usually happens through the following steps⁸:

• Cancer cells invade nearby healthy cells. When a healthy cell is taken over by cancer, the healthy cells begin to replicate (reproduce) more abnormal (cancerous) cells.
• Cancer cells penetrate into the circulatory or lymph system. Once cancer cells replicate, they can break away from where they first formed and enter the circulatory system (bloodstream) or lymphatic system (lymph nodes).
• Migration through circulation. Cancer cells that have broken away from their original location can be carried by the circulatory system or lymph system to other, distant parts of the body, where they can begin forming new tumors.
• Cancer cells lodge in capillaries. Cancer cells may become lodged in the capillaries (tiny vessels) of other parts of the body. Once the cells become lodged and stop moving, they can start dividing and migrating into the surrounding tissue at the distant location.
• New small tumors grow. Cancer cells begin to form small tumors (micrometastases) at the new location elsewhere in the body.

Even if breast cancer has spread to another part of the body, it is still breast cancer and is referred to as metastatic breast cancer. For example, if breast cancer cells have spread to the bones, the diagnosis is metastatic breast cancer with bone metastases, not bone cancer.

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What are the symptoms of metastatic breast cancer?

While early stage breast cancer may not have any signs or symptoms, advanced cancer such as metastatic breast cancer may have signs and symptoms that the patient is aware of. However, metastatic breast cancer symptoms may vary, depending on how far the breast cancer has spread and where in the body the new cancer growth has invaded. 

According to Johns Hopkins, people, especially those who have been treated for breast cancer, should watch for symptoms such as: 

• Unusual or persistent back or neck pain (that is not explained by an injury or exercise)
• Pain in the bones
• Unexplained shortness of breath
• Profound fatigue or malaise (feeling generally unwell)
• Headache
• Seizures
• Mood changes
• Difficulty with speech
• Vision changes

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Metastatic breast cancer symptoms by location

Metastatic breast cancer in the bones

Metastatic breast cancer with bone metastasis is when breast cancer has spread from the original location in the breast to the bones. Although breast cancer can spread to any bone, the most common bones for breast cancer to spread to include the spine, pelvis, and thigh.⁹ Even though the breast cancer has spread to the bones, it is still breast cancer. Metastasis to the bones is the most common type of breast cancer metastasis, impacting approximately 70% of individuals with metastatic breast cancer.¹⁰

Symptoms of metastatic breast cancer in the bones

Sometimes metastasis to the bones can have no symptoms. But if symptoms are present, some of the first signs of metastatic breast cancer in the bones can include¹¹:

• Severe, progressive bone pain, particularly in the spine, ribs, pelvis, or long bones in the arms and legs. Bone pain is the most common symptom of bone metastasis. 
• Swelling of a joint within the skeletal system.
• Weak or fragile bones that are more easily fractured or broken (not as a result of osteoporosis). Such fractures are known as pathological fractures. 
• Weakness in the arms or legs
• High levels of calcium in the blood (hypercalcemia), which can cause nausea, vomiting, constipation, or confusion

Metastatic breast cancer in the lungs

Breast cancer metastasis to the lungs is when breast cancer has spread from the original location in the breast to one or both lungs. Approximately 60% of metastatic breast cancer patients will experience lung metastasis in their life.¹²

Symptoms of metastatic breast cancer in the lungs

Lung metastases rarely produce symptoms in metastatic breast cancer patients. However, if lung metastases do produce symptoms, they can include¹³:

• Chronic cough (a cough that doesn’t go away)
• Inability to take a full breath (shortness of breath)
• Pain or discomfort in the chest area
• Difficulty in catching one’s breath after physical exertion, such as walking up stairs

Metastatic breast cancer in the liver

Breast cancer metastasis in the liver is when breast cancer has spread from the original location in the breast to the liver. Between 5% and 12% of people with metastatic breast cancer will have the liver as the first site of metastasis. However, about 50% of individuals with metastatic breast cancer will develop liver metastases at some point.¹⁴

Symptoms of metastatic breast cancer in the liver

Liver metastases rarely produce symptoms. But when they do occur, symptoms can include:¹⁵

• Jaundice: yellowing of the skin and whites of the eyes; the skin turning dark orange or ashened in color
• Itchy skin or rash
• Abnormally high enzymes in the liver, determined through a blood test
• Abdominal pain, particularly in the right side
• Weakness
• Loss of appetite
• Nausea and vomiting
• Stool color turning light gray

Metastatic breast cancer in the brain

Breast cancer metastasis in the brain means that breast cancer has spread from the original location in the breast to the brain. Even though the breast cancer has spread to the brain, it is still breast cancer. Brain metastasis occurs in approximately 10-15% of women with metastatic breast cancer.¹⁶ However, it is assumed that more patients may have brain metastasis without any symptoms.

Symptoms of metastatic breast cancer in the brain

Metastasis of breast cancer to the brain can cause a variety of symptoms, including¹⁷:

• Persistent, progressively worsening headaches or pressure in the head
• Memory loss
• Vision disturbances, such as blurred vision, double vision, loss of vision, or seeing flashes of light
• Slurred speech 
• Dizziness
• Balance problems
• Weakness or paralysis on one side of the body
• Numbness or tingling in the extremities
• Nausea or vomiting
• Seizures
• Strokes
• Mood, personality, or behavioral changes
• Impaired judgment

If you notice these symptoms, be sure you talk with your physician. They could be important for getting the treatment you need.

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How is metastatic breast cancer diagnosed?

Metastatic breast cancer is often initially investigated based on symptoms. For someone newly diagnosed with Stage 2 or Stage 3 breast cancer, a “staging workup” may be performed to determine if there is any evidence of metastasis (cancer spread) to other organ sites in the body.

Additionally, if someone has Stage 1 breast cancer, and the cancer cells in the breast show the presence of vascular (blood stream) invasion or lymphatic (lymph node) invasion, scans may be conducted to rule out the presence of metastatic disease in other areas of the body.

If a patient is experiencing symptoms of metastatic breast cancer, particularly if the patient had received a previous diagnosis of breast cancer, doctors may order tests to check for metastatic breast cancer.

Tests for metastatic breast cancer

There is no one test to confirm a diagnosis of metastatic breast cancer. Instead, doctors may perform a “staging workup” using a combination of blood and imaging tests to check for metastatic breast cancer. Tests to diagnose metastatic breast cancer may include (not limited to):

• Blood tests, including tumor markers in some patients. Blood tests may also include:
  • Complete blood count (CBC) to assess the body’s bone marrow function
  • Liver enzymes to check for liver metastasis
  • Calcium levels to check for bones metastasis
• Whole-body bone scan, with or without x-rays of specific bones
• MRI (magnetic resonance imaging) of the spine or brain
• CT (computer tomography) scan of the chest, abdomen, pelvis, or brain
• PET (positron emission tomography) scan 
• X-ray or ultrasound of the abdomen or chest
• Bronchoscopy, if there is a persistent cough or trouble breathing
• Biopsy of any suspicious areas
• Tap: Removal of fluid from the area with symptoms to check for cancer cells
  • Pleural tap (thoracentesis): Removes fluid between the lung and chest wall
  • Spinal tap (lumbar puncture): Removes fluid from around the spinal cord
  • Abdominal tap (paracentesis): Removes fluid from the abdominal cavity

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Metastatic breast cancer treatment

Because it is incurable, metastatic breast cancer treatment focuses on shrinking tumors, slowing tumor growth, relieving symptoms, improving patients’ quality of life, and increasing longevity.

Most treatments for metastatic breast cancer are systemic treatments. Systemic treatments are drug therapies that work throughout the whole body, rather than focusing on one specific treatment area. Systemic therapies for metastatic breast cancer may include any combination of:

• Hormonal therapy: A type of drug therapy that keeps breast cancer cells from receiving or using the natural female hormones in the body (estrogen and progesterone) which they need to grow. Hormonal therapy also blocks the ability of healthy breast cells to receive hormones that could stimulate breast cancer cells to regrow. These drugs are commonly combined with CDK4/6 inhibitor therapy.
• Chemotherapy: A treatment method that uses a combination of drugs to either destroy cancer cells or slow down the growth of cancer cells. Chemotherapy is a systemic therapy, meaning that the drugs travel in the bloodstream throughout the entire body.
• Targeted therapy: A treatment method that uses drugs to target specific proteins on cancer cells that may help them grow or spread. Targeted drugs work to destroy or slow down cancerous cell growth and are most commonly used to treat cancer cells that are HER2-positive.
• Immunotherapy: A relatively new form of treatment for women with metastatic breast cancer, which uses the patient’s immune system to fight the cancer.

Metastatic breast cancer drugs

Typically, treatment with one type of drug regimen continues until the cancer starts growing again or until the side effects of the drug become intolerable. At that point, a new drug therapy will be prescribed. Common types of drugs used to treat metastatic breast cancer are listed below.¹⁸ This is not an exhaustive list and all drugs and medications should be discussed with your healthcare provider. NBCF does not endorse any specific medications or brands.

Hormone receptor-positive (HER2+) cancer drugs

• Tamoxifen
• Aromatase inhibitors
• CDK4/6 inhibitor
• Everolimus
• PI3K inhibitor such as alpelisib (Piqray)
• AKT inhibitor such capivasertib (Truqap)

Hormone receptor-negative (HER2-) cancer drugs

• Trastuzumab (Herceptin)
• Pertuzumab (Perjeta)
• Antibody-drug conjugate
• Kinase inhibitor
• Fam-trastuzumab deruxtecan (Enhertu)—for HER2-low cancers
• PARP inhibitor—for women with a BRCA gene mutation

Other metastatic breast cancer immunotherapy drugs

• Pembrolizumab (Keytruda)
• Atezolizumab (Tecentriq)

Local and regional treatment for metastatic breast cancer

Systemic drugs and medications are the most common treatments for metastatic breast cancer. However, local and regional treatments, such as surgery, radiation, or chemotherapy are sometimes used.

These treatments are unlikely to resolve metastatic breast cancer, but they can help prevent or treat the symptoms of the underlying metastatic disease. For example, radiation therapy is sometimes used to radiate the bones of patients with bone metastases that are causing pain. While this does not treat the underlying metastatic disease, it can help relieve bone pain and prevent fractures in some patients. Radiation is also commonly used for metastatic disease to the brain.

Latest treatments for metastatic breast cancer

With the help of metastatic breast cancer clinical trials, many new treatments for metastatic breast cancer, including new drug therapies, are currently under study and treatment is improving. To learn more about metastatic breast cancer clinical trials and look for a trial that might be right for you, search the metastatic breast cancer clinical trial database.

Palliative care and complementary therapies for metastatic breast cancer

Many patients diagnosed with metastatic breast cancer choose to begin palliative care, either immediately upon diagnosis or if symptoms or treatment side effects begin to affect their quality of life. Palliative care is not a treatment for metastatic breast cancer, nor is it hospice care.

Instead, palliative care is supportive care that focuses on the management of symptoms or side effects that are disruptive to a patient’s quality of life. Palliative care may include specialized pain management options, drug therapy to alleviate nausea and increase appetite, emotional care from trained professionals, and more. The goal of palliative care is quality of life preservation or restoration.

Like palliative care, complementary therapies are also not treatments for metastatic breast cancer. Instead, they are practices such as yoga, meditation, acupuncture, mindfulness, and more that focus on a person’s overall physical, mental, and emotional health and well-being. Many patients find complementary therapies soothing and helpful in a time of uncertainty or distress.

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Metastatic breast cancer prognosis

While metastatic breast cancer cannot be completely cured with current cancer treatments available, there is research underway to find better ways to treat, and eventually cure, the disease. With current advancements, many women with metastatic breast cancer are living longer and with increased quality of life by treating it as a chronic illness.

A metastatic breast cancer diagnosis can be overwhelming. Many individuals diagnosed with MBC find it helpful to participate in a support group where they can communicate with and support others with the same diagnosis. NBCF offers virtual and in-person support groups, and there are other support groups available nationwide as well. METAvivor in particular offers support groups and other services specifically for metastatic breast cancer patients.

NBCF hosts weekend retreats for those living with metastatic breast cancer and their caregivers. Metastatic retreats are a time for metastatic patients to come together, along with their caregivers, to offer one another support, hope, and encouragement for what lies ahead. Treatment sessions include the opportunity to ask questions of a breast medical oncologist, end-of-life discussions, opportunities for patients to express their hopes and fears, yoga, meditation, mindfulness, laughter sessions, and card selections for children and grandchildren when they reach future milestones. Email [email protected] for more information on NBCF metastatic retreats.

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Metastatic breast cancer survival rate

According to the American Cancer Society, the 5-year relative survival rate for metastatic breast cancer in women—also called distant breast cancer because the cancer has spread to distant parts of the body—is 31%. The 5-year relative survival rate for metastatic breast cancer in men is 20%, according to the American Cancer Society.

However, survival rates vary widely between individuals based on factors such as a person’s age and general overall health at the time of diagnosis, as well as how each individual responds to treatment methods.

A metastatic breast cancer diagnosis can be scary and overwhelming, and you may experience a range of emotions, from sadness and anger to fear and panic. There is no right or wrong way to process or react to receiving a diagnosis of this magnitude. But there is reason to hope. It is important to remember that treatments for metastatic breast cancer are continually improving and more people are living longer and with higher quality of life than ever before.

NBCF is here to offer you help and support, no matter what diagnosis or treatment you are facing. Please reach out directly at [email protected] for educational information, financial aid resources, information about NBCF metastatic retreats, or any other needs stemming from your diagnosis.

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Metastatic breast cancer and genetic mutations

All patients diagnosed with metastatic breast cancer should consider being tested for the presence of a gene mutation. Reasons for genetic testing include:

• There are specific drug therapies, such as PARP inhibitors, that are available only for patients who carry a breast cancer gene mutation.
• It is important that a patient’s family know if there is a gene mutation that was the original cause of breast cancer. If a patient tests positive for a genetic mutation, each of their siblings and children have a 50% chance of carrying the breast cancer gene mutation. If a patient was genetically tested prior to 2012, it is important for them to be retested as there have been new breast cancer gene mutations discovered by scientists since that time.

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Metastatic breast cancer FAQs

Is it possible to get Stage 4 metastatic breast cancer without going through Stages 1-3 first?

If breast cancer is not detected before it spreads, Stage 4 metastatic breast cancer may be your first diagnosis, called de novo metastatic breast cancer.

If metastatic breast cancer is diagnosed as part of breast cancer recurrence (weeks, months, or years after an initial breast cancer diagnosis and treatment), you may have already experienced Stage 1, Stage 2, or Stage 3 as part of your initial breast cancer diagnosis.

How long can you live with Stage 4 metastatic breast cancer?

Longevity with metastatic breast cancer varies widely between individuals. According to the American Cancer Society, the 5-year relative survival rate for metastatic breast cancer is 31%. That means that at the end of 5 years, 31% of women diagnosed with metastatic breast cancer are still alive. However, it is becoming more common for individuals to live longer with metastatic breast cancer, some even 10 years or more beyond diagnosis. Commonly, the patients with the longest longevity are those whose cancer cells are hormone receptor-positive (HR+) and HER2-negative.¹⁹

What are the final stages of metastatic breast cancer?

Metastatic breast cancer end-of-life symptoms may include²⁰:

• Considerable pain that progresses
• Pronounced fatigue and sleep
• Breathing difficulties
• Lack of appetite
• Weight loss
• Confusion
• Digestive issues
• Emotional changes

Once all available treatment options have been exhausted, or the patient decides to discontinue treatment, many patients will choose to focus on palliative care (supportive care that focuses on the management of symptoms or side effects that are disruptive to a patient’s quality of life) and hospice care to manage the final stages of metastatic breast cancer.

What causes death in metastatic breast cancer?

Infection is the most common cause of death in metastatic breast cancer, followed by organ failure. As patients discontinue treatments as they stop being effective, the next, new treatment undertaken will often be more toxic and accompanied by more side effects. Toward the end of treatment, the drugs are very toxic and usually the benefit of the treatment is minimal. Cancer drugs, commonly chemotherapy used after other treatments have been exhausted, can affect the functioning of the heart, liver, and other organs. Blood counts are also impacted, making it hard for the body to fight infection.

Who has the longest survival for metastatic breast cancer?

Currently, postmenopausal women whose metastatic breast cancer cells are hormone receptor-positive (HR+) and HER2-negative have the longest survival rates. This is likely due to the recent development of a new classification of drugs, CDK4/6 inhibitors. When combined with hormonal therapy, these drugs are enabling women to live longer, sometimes up to 10 years or longer, with metastatic breast cancer than in the past.²¹

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Metastatic breast cancer stories of hope

No matter the stage of breast cancer, NBCF is here to offer help and hope. The NBCF blog, The Hope Nook, offers several hopeful and encouraging stories from women facing metastatic breast cancer:

Confessions of an 18-Year Metastatic Breast Cancer Thriver
Spoiler Alert: She Lives
Marianne’s Story of Finding Hope with Metastatic Breast Cancer

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Sources:

¹ National Institutes of Health
² National Institutes of Health
³ National Institutes of Health
⁴ National Institutes of Health
⁵ Johns Hopkins Medicine
⁶ National Institutes of Health
⁷ American Cancer Society
⁸ Cancer Research UK
⁹ Mayo Clinic
¹⁰ National Institutes of Health
¹¹ Mayo Clinic
¹² National Institutes of Health
¹³ Breastcancer.org
¹⁴ Breastcancer.org
¹⁵ Penn Medicine
¹⁶ Moffitt Cancer Center
¹⁷ Moffitt Cancer Center
¹⁸ American Cancer Society
¹⁹ National Library of Medicine
²⁰ Medical News Today
²¹ National Library of Medicine

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