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f your doctor says that you have metastatic breast cancer, it means the cancer has spread beyond your breasts to other parts of your body. There's no cure, but treatments can ease your symptoms, slow down the cancer's growth, and help you live longer.

You may also hear people call your condition "stage IV" or "advanced breast cancer." When you get a diagnosis, your doctor will explain that cancer cells from your breasts moved through your bloodstream or lymphatic system -- a network of channels, nodes, and glands that help you fight disease. As a result, cancer cells show up in new areas.

The kind of treatment you get has a lot to do with where your cancer has spread. Your doctor will also suggest treatments based on things like:

  • Your symptoms
  • What treatments you've already had
  • What type of cancer cells you have

Some treatments work better on different kinds of breast cancer cells. To find out more about your cells, your doctor will take samples of your blood and tissue. They're sent to a lab, where technicians look at them under a microscope. This can reveal what's making your cells grow, so you can take a medicine that targets that feature. 

Your doctor may tell you that you have one of these types of metastatic breast cancer cells:

Hormone-receptor-positive. These cells have proteins called hormone "receptors." The job of these receptors is to catch -- or "bind" to -- certain hormones as they move through your body. If you have hormone-receptor-positive breast cancer, the receptors bind to estrogen and progesterone hormones. These hormones stimulate the growth of breast cancer cells. In most cases, breast cancer is hormone-positive.
 
Hormone-receptor-negative. The cells don't have hormone receptors.

HER2-positive. A gene called human epidermal growth factor receptor 2 (HER2) makes HER2 protein. These proteins act as receptors. Some breast cancer cells make too many HER2 proteins. When this happens, the cells grow faster than usual.
 
HER2-negative in women with a PIK3CA mutation. If you have this type, your cancer cells don't have large amounts of HER2 protein. You'll also have signs of a mutation (change) on a gene called the PIK3CA. This may play a role in how the cells turn cancerous.

HER2-negative in women with a BRCA mutation. Along with a normal amount of HER2 protein, you have a mutation on the BRCA 1 or 2 gene. This can lead to abnormal cell growth.
 
Triple-negative. This kind of breast cancer takes its name from things that your cancer cells are lacking. The cells don’t have many estrogen or progesterone receptors, or a lot of HER2 protein. About 20% of the time, triple-negative tumors make a protein called PD-L1, which can play a useful role in certain treatments. 

Based on your cancer and medical history, your doctor will suggest the treatments that are most likely to work with the fewest side effects. Some treatments are "systemic," which means they work on your entire body. Others are local, or focus on one area. You may need one treatment or a combination of them.

Hormone Therapy

This may be a part of treatment if you have these types of cancer cells:
  • Hormone-receptor-positive

Why you might choose it:

Hormone therapy is often the first treatment your doctor will suggest if you have hormone-receptor-positive cancer. This treatment works by stopping hormones from attaching to the receptors. It may block the receptor or lower the amount of estrogen that your body makes. This prevents breast cancer cell growth.

Types:

Tamoxifen

This drug blocks estrogen receptors in breast cells. You usually take it every day as a pill.

Toremifene (Fareston)

It's a once-a-day pill that works like tamoxifen to prevent estrogen from attaching to cancer cells. The FDA has approved it only for women who have already gone through menopause.

Fulvestrant (Faslodex)

This medicine also blocks and damages estrogen receptors. Doctors often suggest it if you've tried other hormone therapies, such as tamoxifen, but they aren't working anymore. Sometimes they recommend it for advanced breast cancer if you haven't been treated with other hormone therapies. You usually take fulvestrant as a shot every 2 weeks for 1 month, and then once a month. The FDA has approved it for women who are done with menopause, but doctors sometimes prescribe it for premenopausal women, too.

Aromatase inhibitors

These drugs stop an enzyme from making estrogen. Doctors prescribe them if you're finished with menopause. You take it every day as a pill.

Side effects:

  • Hot flashes
  • Vaginal dryness
  • Headache
  • Nausea
  • Bone pain
  • Joint and muscle pain

In rare cases, you may get more serious side effects, such as:

  • Blood clots
  • Stroke
  • Osteoporosis
  • Heart disease

It's rare, but tamoxifen can raise your risk of uterine cancer.

Radiation Therapy

This may be a part of treatment if you have these types of cancer cells:
  • Hormone-receptor-positive
  • Hormone-receptor-negative
  • HER2-positive
  • HER2-negative in women with a PIK3CA mutation
  • HER2-negative in women with a BRCA mutation
  • Triple-negative

Why you might choose it:

Your doctor may suggest radiation therapy to ease symptoms and control cancer in certain areas of your body. This treatment uses high-energy X-rays or other particles to kill cancer cells. For example, if your breast cancer has spread to your liver, radiation may help shrink the tumor. This can help lessen the pain.

Types:

External beam radiation therapy

A machine sends out high-energy rays that pass through your skin into the tumor.

Stereotactic body radiation therapy

Different beams target a tumor to deliver a high dose of radiation.

Radiopharmaceuticals

These drugs are made of a radioactive substance. You take the drug as a shot or swallow it, and it gives off radiation and kills cancer cells.

Side effects:

  • Fatigue
  • Skin issues, such as itchiness, redness, peeling, or blistering
  • Swelling in the breasts

Chemotherapy

This may be a part of treatment if you have these types of cancer cells:
  • Hormone-receptor-positive
  • Hormone-receptor-negative
  • HER2-positive
  • HER2-negative in women with a PIK3CA mutation
  • HER2-negative in women with a BRCA mutation
  • Triple-negative

Why you might choose it:

Chemotherapy uses chemicals to kill fast-growing cancer cells. It's the main option if you have hormone-receptor-negative cancer. Your doctor may also suggest it if you tried hormone therapy and it didn't work. Chemotherapy is also a choice if your cancer is growing quickly or causing symptoms.

Types:

Several different chemotherapy drugs can treat metastatic breast cancer. Your doctor will choose one or more based on the type of cancer cells you have. You may need to take them separately, one after another, or as a combination.

You take some chemotherapy medicines as pills. You get others through an IV.

Side effects:

Chemotherapy drugs can't tell the difference between cancer and normal cells. They damage healthy cells, which causes side effects. During treatment, you may have:

  • Hair loss
  • Mouth sores
  • Loss of appetite
  • Nausea and vomiting
  • Diarrhea
  • Pain
  • Constipation
  • Fatigue
  • Fever

Talk to your doctor if you have any of these problems. They can suggest medicines that can give you relief.

Months or years after chemotherapy, other side effects may show up, such as:

  • Nerve damage
  • Heart or kidney problems
  • Infertility
  • Lung tissue damage
  • Increased risk of a second cancer

Targeted Therapy

This may be a part of treatment if you have these types of cancer cells:
  • Hormone-receptor-positive
  • HER2-positive
  • HER2-negative in women with a PIK3CA mutation
  • HER2-negative in women with a BRCA mutation

Why you might choose it:

These drugs zero in on certain cancer cells. They block specific molecules involved in the growth and spread of cancer. And some targeted drugs may not have as many side effects as chemotherapy.

Types:

Your doctor will suggest a targeted therapy based on your cancer cells. You take some through an IV, while you take others as a pill.

Abemaciclib (Verzenio)

It curbs the activity of CDK4 and CDK6 enzymes, which helps stop cancer cells from dividing and growing.

Ado-trastuzumab emtansine (Kadcyla)

This medication is a combination of Herceptin and a chemotherapy drug.

Alpelisib (Piqray)

This drug is a type called a "P13K inhibitor." You might use it if you have HER2-negative, hormone-receptor-positive cancer cells with a P1K3CA mutation.

Bevacizumab (Avastin)

It blocks the growth of new blood vessels in your cancer cells.

Everolimus (Afinitor)

Your doctor may suggest this drug if you have hormone-receptor-positive, HER2-negative cancer. It prevents cancer cells from getting the energy they need.

Lapatinib (Tykerb)

It blocks certain proteins in HER2-positive cells.

Olaparib (Lynparza)

This drug curbs the action of an enzyme called PARP. The job of PARP is to repair DNA damage in cells. That's OK if it's fixing damaged healthy cells, but it's not so useful when it's repairing cancer cells. Your doctor may suggest Lynparza if you have HER2-negative cells with a BRCA mutation.

Palbociclib (Ibrance)

It prevents hormone-receptor-positive, HER2-negative cells from dividing and growing. They target enzymes called CDK4 and CDK6.

Pertuzumab (Perjeta)

This medicine blocks HER2 receptors.

Ribociclib (Kisqali)

It blocks CDK4 and CDK6 enzymes to prevent breast cancer cells from dividing and growing.

Talazoparib (Talzenna)

It blocks the PARP enzymes. You might use it if you have HER2-negative cells with a BRCA mutation.

Trastuzumab (Herceptin)

This medicine attaches to HER2 receptors to keep breast cancer cells from getting growth signals.

Side effects:

  • Diarrhea
  • Liver problems, such as hepatitis
  • High blood pressure
  • Skin problems, such as rashes and dry skin
  • Issues with blood clotting and wound healing

In rare cases, some targeted therapies may lead to a hole in the gastrointestinal tract, called a gastrointestinal perforation.

What's ahead:

There are many targeted therapy drugs in the research pipeline. Some of them target CDK4 and CDK6 enzymes and HER2 receptors.

Another medication that scientists are studying is the combination drug sacituzumab govitecan. It combines a drug that targets a specific protein with a chemotherapy drug. Researchers want to see if it works for people with triple-negative cancer.

Your doctor may suggest you take any of the targeted therapy drugs now approved by the FDA for metastatic breast cancer along with chemotherapy.

Immunotherapy

This may be a part of treatment if you have these types of cancer cells:
  • Triple-negative

Why you might choose it:

Immunotherapy helps your body's own immune system fight cancer cells. Your doctor will recommend it if you have triple-negative tumors that make the PD-L1 protein.

Types:

Atezolizumab (Tecentriq)

This drug is a type of immunotherapy called a checkpoint inhibitor. You take it by IV, and your doctor may suggest you also take the chemotherapy drug called paclitaxel (Abraxane) along with it.

Side effects:

If you take the immunotherapy drug Tecentriq, you could get side effects such as:

  • Skin reactions, such as redness, blistering, dryness, and sun sensitivity
  • Flu-like symptoms, including fatigue, fever, and chills
  • Nausea and vomiting
  • High or low blood pressure
  • Muscle aches
  • Shortness of breath
  • Headaches
  • Diarrhea
  • Cough
  • Hormone changes, such as hypothyroidism

Checkpoint inhibitors work by targeting proteins in immune cells that doctors call "checkpoints." The checkpoint inhibitors "lift the brakes" on these immune cells so that they can attack your cancer cells.

What's ahead:

Researchers are looking at a checkpoint inhibitor called pembrolizumab (Keytruda). It might be able to help if you have triple-negative breast cancer. Scientists want to see if it can block the action of PD-1 and PD-L1 proteins to allow your immune system to better fight cancer cells.

Surgery

This may be a part of treatment if you have these types of cancer cells:
  • Hormone-receptor-positive
  • Hormone-receptor-negative
  • HER2-positive
  • HER2-negative in women with a PIK3CA mutation
  • HER2-negative in women with a BRCA mutation
  • Triple-negative

Why you might choose it:

Surgery is an option if your metastatic cancer is the first time you've been diagnosed with breast cancer. Your doctor may also suggest it if a tumor's causing a lot of symptoms or if there's a risk of a serious complication. For example, if your breast cancer has spread and presses on your spinal cord, it may lead to leg weakness.

Types:

Operation to remove the breast tumor

If you first learned that you had breast cancer when the disease had already spread to other parts of your body, you may benefit from having a surgeon take out the tumor in your breast.

Cryoablation

In this procedure, a doctor puts a cold probe into your tumor to freeze the tissue.

Side effects:

Cryoablation, like any procedure, can have side effects. You might get:

  • Bleeding
  • Damage to nearby tissues
  • Nerve damage
  • Infection
  • Pain
  • Lymphedema, or swelling caused by too much fluid in the tissue

Bone-Strengthening Drugs

Why you might choose one:

If your breast cancer has spread to your bones, your doctor may suggest drugs that prevent breaks and ease bone pain.

Types:

Denosumab (Xgeva)

This drug interferes with osteoclasts, the cells that break down bone tissue. You take it as shot that you get once a month.

Zoledronic acid (Zometa)

This medicine also blocks osteoclasts. You take it through an IV every 1 to 3 months.

Side effects:

  • Headaches
  • Flu-like symptoms, such as chills and muscle aches

In rare cases, bone-strengthening drugs may cause kidney problems or bone damage in the jaw from osteonecrosis.

Palliative Care

These are treatments that ease symptoms and pain, but they don't fight the disease. You may have palliative care along with your other treatments.

Why you might choose it:

The goal of palliative care is to make you feel as comfortable as possible. It may help lessen pain, symptoms, and the side effects of treatment, such as nausea and dizziness. It may improve your appetite, boost your energy, and help you sleep better. It can include medicines, such as anti-nausea drugs and antidepressants.

Complementary Treatments

Why you might choose one:

These natural products and mind-body practices may help ease treatment side effects. They may also curb stress and improve your quality of life. Before you try one, check with your doctor that it's safe and won't react badly with any of your treatments.

Types:

There are many kinds of complementary treatments, including:

Acupuncture

A practitioner puts thin needles into points in your skin. This is meant to activate the release of natural painkillers.

Massage

This hands-on therapy may help with stress and pain.

Meditation

In this practice, you focus on a relaxed mental and physical state. It may help ease stress, fatigue, and more.

Yoga

This mind-body practice may lessen stress, anxiety, and fatigue.

Dietary supplements

These may include herbs, vitamins, minerals, and probiotics.

Clinical Trials

Researchers are trying all the time to find new treatments for metastatic breast cancer. They test drugs, devices, or procedures in studies called "clinical trials" to see if they work well and are safe. Ask your doctor if joining one is a good idea for you.

Why you might choose one:

If you take part in a clinical trial, you get a chance to try treatments that aren't available to the public yet. The medications you get in the trial might improve your condition or ease symptoms. By joining a clinical trial, you'll also help doctors add to their knowledge of breast cancer care and improve the treatment of people in the future.

Types:

Some clinical trials may test brand-new drugs. Others check to see if medicine that's already used for another purpose may help treat metastatic breast cancer. Researchers also want to know if it’s helpful to combine medications in new ways.

No matter what kind of treatment the clinical trial is testing, researchers want to find out things like:

  • Correct dosage
  • Whether it helps people live longer
  • Side effects
  • Best way to take the treatment

Choosing Your Path

Keep in mind that you're in charge of your treatment journey. Some cancer treatment side effects can be tough. It's OK to talk to your doctor about taking a break. You can work out a plan, and your medical team can help you stay comfortable until you decide whether or not to start cancer treatment again. You should also set up a schedule to check in on a regular basis.