Breast Cancer - Metastatic: Types of Treatment

Aprobado por la Junta Editorial de Cancer.Net, 04/2019

ON THIS PAGE: You will learn about the different types of treatments doctors use for people with metastatic breast cancer. Use the menu to see other pages.

This section explains the types of treatments that are the standard of care for metastatic breast cancer. “Standard of care” means the best treatments known. When making treatment plan decisions, you are encouraged to consider clinical trials as an option. A clinical trial is a research study that tests a new approach to treatment. Doctors want to learn whether the new treatment is safe, effective, and possibly better than the standard treatment. Clinical trials can test a new drug and how often it should be given, a new combination of standard treatments, or new doses of standard drugs or other treatments. Clinical trials are an option to consider for treatment and care for all stages of cancer. Your doctor can help you consider all your treatment options. Learn more about clinical trials in the About Clinical Trials and Latest Research sections of this guide.

Researchers are also using other methods to better understand metastatic breast cancer and identify new treatment approaches. For example, the Metastatic Breast Cancer Project allows people with metastatic breast cancer to enroll themselves. Please note that this link takes you to another, independent website.

If you are diagnosed with metastatic breast cancer, it is a good idea to talk with doctors who have experience in treating it. Doctors can have different opinions about the best standard treatment plan. Learn more about getting a second opinion before starting treatment, so you are comfortable with your chosen treatment plan.

Treatment overview

In cancer care, different types of doctors often work together to create a patient’s overall treatment plan that combines different types of treatments. This is called a multidisciplinary team. Cancer care teams include a variety of other health care professionals, such as physician assistants, oncology nurses, social workers, pharmacists, counselors, dietitians, and others. Ask the doctor in charge of your treatment which health care professionals will be part of your treatment team and what they do. This can change over time as your health care needs change.

A treatment plan is a summary of your cancer and the planned cancer treatment. It is meant to give basic information about your medical history to any doctors who will care for you during your lifetime. Before treatment begins, ask your doctor for a copy of your treatment plan. You can also give your doctor a copy of an ASCO Treatment Plan form to fill out.

The main goals of metastatic breast cancer treatment are to make sure that you have the:

  • Longest survival possible with the disease

  • Fewest possible side effects from the cancer and its treatment

  • Best and longest quality of life possible

There is no cure for metastatic cancer, but a good quality of life is possible for months or even years.

Treatment options for metastatic breast cancer vary based on:

  • Where in the body the cancer has spread

  • The presence and level of hormone receptors and/or HER2 in the tumor

  • Gene mutations in the tumor

  • Specific symptoms

  • Previous cancer treatments

  • Your overall health

How well treatment works depends on many factors as well, including how widespread the cancer is and what treatments have already been used. Because it is not unusual for metastatic breast cancer to stop responding to drugs over time, you may need to change treatments fairly often.

After testing is done, you and your doctor will talk about your treatment options. Your treatment plan may include certain treatments described below, but they may be used in a different combination or at a different pace. Your care plan also includes treatment for symptoms and side effects, an important part of cancer care.

Take time to learn about all of your treatment options and be sure to ask questions about things that are unclear. Talk with your doctor about the goals of each treatment and what you can expect while receiving the treatment. These types of talks are called “shared decision making.” Shared decision making is when you and your doctors work together to choose treatments that fit the goals of your care. Shared decision making is particularly important for metastatic breast cancer because there are different treatment options. Learn more about making treatment decisions.

Therapies using medication

Systemic therapy is the use of medication to destroy cancer cells. This type of medication is given through the bloodstream to reach cancer cells throughout the body. Systemic therapies are generally prescribed by a medical oncologist, a doctor who specializes in treating cancer with medication.

Common ways to give systemic therapies include an intravenous (IV) tube placed into a vein using a needle or in a pill or capsule that is swallowed (orally).

The types of systemic therapies used for metastatic breast cancer include:

  • Hormonal therapy

  • Chemotherapy

  • Targeted therapy

  • Immunotherapy

Each of these types of therapies are discussed below in more detail. A person may receive 1 type of systemic therapy at a time or a combination of systemic therapies given at the same time. The first set of drugs used for metastatic disease is called first-line treatment. If the cancer worsens or comes back, another combination of drugs may be used, called second-line treatment. These therapies can also be given as part of a treatment plan that includes surgery and/or radiation therapy.

The medications used to treat cancer are continually being evaluated. Talking with your doctor is often the best way to learn about the medications prescribed for you, their purpose, and their potential side effects or interactions with other medications. It is also important to let your doctor know if you are taking any other prescription or over-the-counter medications or supplements. Herbs, supplements, and other drugs can interact with cancer medications. Learn more about your prescriptions by using searchable drug databases.

Hormonal therapy (updated 02/2020)

Hormonal therapy, also called endocrine therapy, is an effective treatment for many tumors that test positive for either ER or PR.

Hormone receptor-positive tumors may use hormones to fuel their growth. The goal of this type of therapy is to lower the levels of estrogen and progesterone in the body or to block these hormones from getting to cancer cells. If the hormones cannot get to the cancer cells, the cancer cannot use them to grow.

In general, hormonal therapy is recommended for all patients with hormone receptor-positive breast cancer. The available treatment options are based on several factors:

  • If you are a woman, whether you are still menstruating or have gone through menopause

  • The type of treatment you have already received or are receiving

  • How long it had been before your cancer recurred

  • How widespread the cancer is and whether you have symptoms that need to be managed

  • What your gender is

Options for hormonal therapy include:

  • Tamoxifen (Soltamox). Tamoxifen is a drug that blocks estrogen from binding to breast cancer cells. It is a pill taken daily by mouth. Common side effects of tamoxifen include hot flashes as well as vaginal discharge or bleeding. Very rare risks include a cancer of the lining of the uterus, cataracts, and blood clots. However, tamoxifen may improve bone health and cholesterol levels. The treatment is an option for both premenopausal and postmenopausal women and for men.

  • Aromatase inhibitors (AIs). AIs decrease the amount of estrogen made by tissues other than the ovaries by blocking the aromatase enzyme. This enzyme changes hormones called androgens into estrogens. These drugs include anastrozole (Arimidex), exemestane (Aromasin), and letrozole (Femara). All of the AIs are pills taken daily by mouth.

    Side effects of AIs may include joint stiffness, sometimes with joint aches. AIs may also cause hot flashes, vaginal dryness, an increased risk of osteoporosis and broken bones, and increased cholesterol levels. Research shows that all 3 AIs work equally well and have similar side effects. However, patients who experience too many side effects while taking 1 AI may have fewer side effects with another AI for unclear reasons. Both premenopausal women and men can take AIs as long as they are given in combination with an injectable medication. Women who have not gone through menopause should not take AIs, as they do not block the effects of estrogen made by the ovaries. Often, doctors will monitor blood estrogen levels in women whose periods have recently stopped, or in those whose periods have stopped because of chemotherapy, to be sure that the ovaries are no longer making estrogen.

  • Ovarian suppression. This is the use of drugs or surgery to stop the ovaries from producing estrogen. It may be used in combination with tamoxifen, an AI, or fulvestrant (see below). Drugs called gonadotropin or luteinizing releasing hormone (GnRH or LHRH) analogs can stop the ovaries from making estrogen, causing temporary menopause. Some examples of these medicines include goserelin (Zoladex) or leuprolide (Eligard, Lupron), which are usually taken monthly. Surgery to remove both ovaries permanently stops estrogen production.

    Ovarian suppression is commonly used as a part of treatment for hormone receptor-positive metastatic breast cancer in women who have not been through menopause. This is because completely blocking estrogen may be helpful against the cancer.

  • Fulvestrant (Faslodex). Fulvestrant is a selective estrogen receptor downregulator (SERD) that blocks the ability of estrogen to attach to estrogen receptors. Unlike other oral hormonal therapies, fulvestrant is given monthly by an injection into a muscle. Most commonly, 2 injections are given every 2 weeks for the first 3 doses and then continued monthly. Fulvestrant is only for women who have been through menopause, although as noted below, it can also be used to treat men.

  • Other hormonal therapies. Other hormonal therapies occasionally used to treat metastatic breast cancer after AIs, fulvestrant, tamoxifen, and targeted therapy (see below) include megestrol acetate (Megace) and high-dose estradiol.

For women with metastatic hormone receptor-positive breast cancer, recommendations for hormonal therapy include:

  • Fulvestrant or an AI for women who have been through menopause.

  • Ovarian suppression or removal of the ovaries and hormonal therapy with either tamoxifen or an AI for women who have not been through menopause.

  • The combination of anastrozole or letrozole and fulvestrant is an option for patients who have not previously had hormonal therapy.

  • If the first hormonal therapy given no longer works, another type may be an option unless the disease has worsened quickly and is affecting how well the body’s organs are working.

For men with metastatic hormone receptor-positive, HER2-negative breast cancer, ASCO recommends hormonal therapy with tamoxifen. Other options include an AI combined with a medication to lower androgen production (such as goserelin [Zoladex] or leuprolide [Eligard, Lupron], or fulvestrant. If metastatic hormone receptor-positive, HER2-negative breast cancer recurs or progresses during hormonal therapy, different hormonal therapy should be offered when possible.

Some types of targeted therapy (see below) may be combined with hormonal therapy for metastatic breast cancer. However, chemotherapy is not recommended along with hormonal therapy.

This information is based on ASCO’s recommendations for hormonal therapy for metastatic breast cancer and for the management of male breast cancer. Please note that these links take you to a separate ASCO website.

Chemotherapy (updated 04/2020)

Chemotherapy is the use of drugs to destroy cancer cells, usually by keeping the cancer cells from growing, dividing, and making more cells.

Chemotherapy for metastatic breast cancer can be given on many different schedules depending on what worked best in clinical trials for that specific type of regimen, or schedule. It may be given once a week, once every 2 weeks (also called dose-dense), once every 3 weeks, or even once every 4 weeks. Weekly schedules often include weeks off as a break. In general, chemotherapy is often given continuously as long as it is working against the cancer and the patient isn’t experiencing too many side effects.

A patient with metastatic breast cancer usually receives 1 drug at a time, which means 1 after another, rather than as a combination, although occasionally a combination regimen is recommended. The best chemotherapy option for each patient depends on several factors, including the previous treatment received, potential side effects, the patient’s overall health, and the patient’s preferences. People with inherited BRCA mutations who have metastatic breast cancer should be offered platinum chemotherapy, if possible.

Drugs that may be used for metastatic breast cancer include:

  • Capecitabine (Xeloda)

  • Carboplatin (available as a generic drug)

  • Cisplatin (available as a generic drug)

  • Cyclophosphamide (available as a generic drug)

  • Docetaxel (Taxotere)

  • Doxorubicin (available as a generic drug)

  • Pegylated liposomal doxorubicin (Doxil)

  • Epirubicin (Ellence)

  • Eribulin (Halaven)

  • Fluorouracil (5-FU)

  • Gemcitabine (Gemzar)

  • Ixabepilone (Ixempra)

  • Methotrexate (Rheumatrex, Trexall)

  • Paclitaxel (Taxol)

  • Protein-bound paclitaxel (Abraxane)

  • Vinorelbine (Navelbine)

Chemotherapy may be combined with other types of treatments. For example, therapies that target the HER2 receptor, such as the antibody trastuzumab, may be given with chemotherapy for HER2-positive breast cancer (see Targeted therapy, below).

The side effects of chemotherapy depend on the individual, the drug(s) used, and the schedule and dose used. These side effects can include fatigue, risk of infection, nausea and vomiting, hair loss, loss of appetite, numbness from nerve damage, and diarrhea. These side effects can often be very successfully prevented or managed during treatment with supportive medications, and they usually go away after treatment is finished.

Many patients feel reasonably well during chemotherapy treatment and are active taking care of their families, traveling, and exercising during treatment, although each person’s experience can be different. Talk with your health care team about the possible side effects of your specific chemotherapy plan.

Learn more about the basics of chemotherapy.

Targeted therapy (updated 02/2020)

Targeted therapy is a treatment that targets the cancer’s specific genes, proteins, or the tissue environment that contributes to cancer growth and survival. These treatments are very focused and work differently than chemotherapy or hormonal therapy. This type of treatment blocks the growth and spread of cancer cells while limiting damage to healthy cells.

Not all tumors have the same targets. To find the most effective treatment, your doctor may run tests to identify the genes, proteins, and other factors in your tumor. This helps doctors better match each patient with the most effective treatment whenever possible. In addition, research studies continue to find out more about specific molecular targets and new treatments directed at them. Learn more about the basics of targeted treatments.

There are different types of targeted therapies that vary in how they target the cancer cells:

  • Monoclonal antibodies. A monoclonal antibody recognizes and attaches to a specific protein in the cancer cells, and it does not affect cells that do not have that protein. Examples of monoclonal antibodies used for breast cancer include trastuzumab, pertuzumab, trastuzumab deruxtecan, TDM-1, sacituzumab govitecan-hziy, pembrolizumab, and atezolizumab (see below).

  • Small molecule inhibitors. Small molecule inhibitors are drugs designed to specifically target parts of a cancer cell that contribute to its growth and survival. The parts of a cancer cell that these drugs target may be receptors on the outside of the cell, enzymes on the inside of a cell, or a protein important for cell growth. Some of these types of drugs may target different parts of a cell. These are called “multi-targeted.” Small molecule inhibitors are often pills. Examples used for breast cancer include lapatinib, palbociclib, ribociclib, abemaciclib, olaparib, talazoparib, alpelisib, and everolimus (see below).

  • Tumor agnostic treatments. A tumor-agnostic treatment is a drug treatment that is used to treat any kind of cancer, regardless of where in the body it started or the type of tissue from which it developed. This type of treatment can be used when the tumor has a very specific molecular alteration that is targeted by the drug. The drug larotrectinib (Vitrakvi) is an example of a tumor agnostic targeted therapy. It is approved for any cancer with an NTRK fusion, including breast cancer, that is metastatic or cannot be removed with surgery and has worsened with other treatments. Another tumor-agnostic treatment for breast cancer is a type of immunotherapy called pembrolizumab (Keytruda; see Immunotherapy, below).

ASCO recommendations support using the same targeted therapies to treat metastatic breast cancer in men and women. Talk with your doctor about possible side effects of specific targeted therapies and how they can be managed.

Targeted therapy for metastatic HER2-positive breast cancer (updated 07/2020)

HER2-targeted therapies can be used to treat HER2-positive metastatic breast cancer. Some of these drugs may be used together with chemotherapy. In general, for a person with HER2-positive metastatic breast cancer, there is almost always a HER2-targeted therapy being used along with another systemic therapy.

Some of the HER2-targeted therapies may not be able to penetrate into the brain as easily as they reach the rest of the body. So, HER2-positive metastatic breast cancer that has spread to the brain is often treated with surgery and/or radiation therapy (see below).

  • Trastuzumab (Herceptin, Herceptin Hylecta, Herzuma, Ogivri, Ontruzant). For metastatic breast cancer, trastuzumab can be given in combination with different types of chemotherapy or with hormonal therapy. Trastuzumab can be given in a vein as a weekly infusion, or either in a vein or an injection under the skin once every 3 weeks. Patients receiving trastuzumab have a small (2% to 5%) risk of heart problems and should have monitoring with an echocardiogram.

  • Pertuzumab (Perjeta). Research shows that adding pertuzumab to trastuzumab and chemotherapy as part of first-line therapy for HER2-positive metastatic breast cancer lengthens lives with few additional side effects. Based on this data, the combination of trastuzumab, pertuzumab, and chemotherapy has become a standard of care for the first-line treatment of untreated metastatic HER2-positive breast cancer. Pertuzumab is an intravenous medication and generally causes few side effects, although it can occasionally cause diarrhea. 

  • Pertuzumab, trastuzumab, and hyaluronidase–zzxf (Phesgo). This combination drug, which contains pertuzumab, trastuzumab, and hyaluronidase-zzxf in a single dose, is approved for people with metastatic HER2-positive breast cancer. It is given by injection under the skin in combination with docetaxel and can be administered either at a treatment center or at home by a health care professional. The most common side effects of this drug when given with chemotherapy are hair loss, nausea, diarrhea, lowered red blood cell count, and, a lack of energy.

  • Ado-trastuzumab emtansine or T-DM1 (Kadcyla). This is approved for the treatment of metastatic breast cancer for patients who have previously received trastuzumab and chemotherapy with either paclitaxel or docetaxel. T-DM1 is a combination of trastuzumab linked to very small amount of a strong chemotherapy. This allows the drug to deliver chemotherapy into the cancer cell while lessening the chemotherapy received by healthy cells. T-DM1 is given by vein every 3 weeks. Patients receiving this drug have a small risk of heart problems and liver abnormalities and should have monitoring.

  • Trastuzumab deruxtecan (Enhertu). Trastuzumab deruxtecan is approved for treatment of patients with metastatic HER2-positive breast cancer who have already received 2 or more HER2-targeted therapies. This HER2-targeted treatment is a combination of a drug that is similar to trastuzumab, called a biosimilar, linked to a small amount of a strong chemotherapy. The trastuzumab biosimilar carries the chemotherapy to the HER2-positive cancer cells, so it can kill the cancer cells and limit damage to healthy cells. It is given by vein every 3 weeks. The treatment has a low risk of interstitial lung disease (ILD), which causes scarring of the lungs and can make it difficult to breathe or cause coughing.

  • Tucatinib (Tukysa). Tucatinib, when added to capecitabine chemotherapy and trastuzumab, is approved for the treatment of advanced unresectable or metastatic HER2-positive breast cancer, including cancer that has spread to the brain, in those who have already received 1 or more HER2-targeted therapy. Unresectable means surgery is not an option. Tucatinib is a tyrosine kinase inhibitor designed to turn off HER2. It is an oral medication that is given twice daily. This drug can cause diarrhea and affect the liver.

  • Neratinib (Nerlynx). Neratinib, in combination with capecitabine chemotherapy, is approved for the treatment of advanced or metastatic HER2-positive breast cancer in patients who have already received 2 or more HER2-targeted therapies. Neratinib is a tyrosine kinase inhibitor. It is an oral medication that is given every day for 3 weeks. This drug can cause diarrhea and can also affect the liver.

  • Lapatinib (Tykerb). Women with HER2-positive metastatic breast cancer may benefit from lapatinib when other medications are no longer effective at controlling the cancer’s growth. The combination of lapatinib and the chemotherapy capecitabine is approved to treat metastatic HER2-positive breast cancer when a patient has already received chemotherapy and trastuzumab. The combination of lapatinib and letrozole is also approved for metastatic HER2-positive and ER-positive cancer. Lapatinib is also used in combination with trastuzumab for patients whose cancer is growing while receiving trastuzumab. Lapatinib may be able to enter into the brain, and could be an option for HER2-positive breast cancer that has spread to the brain. This drug can affect the liver and can also cause diarrhea.

Targeted therapy for metastatic hormone receptor-positive, HER2-negative breast cancer
  • Palbociclib (Ibrance). This oral drug targets a protein in breast cancer cells called CDK4/6, which may stimulate cancer cell growth. Used along with the AI letrozole, the drug is an option for women who have been through menopause and have ER-positive, HER2-negative metastatic breast cancer. Palbociclib can also be used with fulvestrant if the cancer has worsened after receiving other hormonal therapy. Palbociclib generally has few side effects. It can lower the number of white blood cells. But it does not appear to increase the risk of serious infections that are linked to low numbers of white blood cells.

  • Ribociclib (Kisqali). This oral drug also targets CDK4/6. Used with an AI or fulvestrant, it is an option for women who have been through menopause and have ER-positive, HER2-negative metastatic breast cancer. Side effects of ribociclib can include low numbers of white blood cells, increases in enzymes linked with liver damage, and changes in heart rhythms.

  • Abemaciclib (Verzenio) This is another oral drug that targets CDK4/6. It is approved by the FDA as a first-line treatment along with an AI for women who have been through menopause and have ER-positive, HER2-negative metastatic breast cancer. It may also be used along with fulvestrant if the cancer has worsened with other hormonal therapies. Abemaciclib may also be used alone as a treatment. It does not lower blood counts as much as the other CDK4/6 drugs, but it is more likely to cause diarrhea, which can be severe at times.

  • Everolimus (Afinitor, Zortress). Everolimus is used with the AI exemestane for ER-positive, HER2-negative metastatic breast cancer that has grown despite treatment with another AI. Side effects of everolimus can include mouth sores, rash, diarrhea, and, rarely, an inflammation of the lungs called interstitial pneumonitis.

  • Alpelisib (Piqray). Alpelisib is an option along with the hormonal therapy fulvestrant for men and women with hormone receptor-positive, HER2-negative metastatic breast cancer that has a PIK3CA gene mutation and has worsened during or after hormonal therapy. Side effects include diarrhea, rash, fatigue, changes in numbers of blood cells, nausea and vomiting, mouth sores, and changes in certain substances found in the blood, including high sugar levels and enzymes linked with liver damage.

Targeted therapy for metastatic triple-negative breast cancer (updated 04/2020)
  • Sacituzumab govitecan-hziy (Trodelvy). In 2020, the FDA approved the use of sacituzumab govitecan-hziy for the treatment of people with metastatic triple-negative breast cancer who have already received at least 2 treatments. Sacituzumab govitecan-hziy is an antibody-drug conjugate, which means the antibody attaches to a cancer cell and then delivers the anticancer drug it carries to start destroying the cancer cell. Sacituzumab govitecan-hziy is given by vein, or intravenously, on days 1 and 8 of every 21-day cycle. Common side effects are neutropenia, diarrhea, nausea and vomiting, and allergic reaction.
Targeted therapy for people who have a BRCA1 or BRCA2 gene mutation (updated 04/2020)
  • Olaparib (Lynparza). This oral drug may be used for patients with metastatic HER2-negative breast cancer and a BRCA1 or BRCA2 gene mutation as an alternative to chemotherapy. It is a type of drug called a PARP inhibitor, which destroys cancer cells by preventing them from fixing damage. Common side effects include fatigue, anemia, and occasionally nausea, vomiting, and diarrhea.

  • Talazoparib (Talzenna). This drug is another option for patients with metastatic HER2-negative breast cancer and a BRCA1 or BRCA2 gene mutation as an alternative to chemotherapy. It is also a PARP inhibitor (see above). The most common side effects include fatigue, anemia, nausea and vomiting, headache, diarrhea, decreased appetite, hair loss, and lower levels of certain blood cells.

This information is based on ASCO’s recommendations for the management of hereditary breast cancerPlease note that this link takes you to a separate ASCO website. 


Immunotherapy, also called biologic therapy, is designed to boost the body's natural defenses to fight the cancer. It uses materials made either by the body or in a laboratory to improve, target, or restore immune system function.

  • Atezolizumab (Tecentriq). In 2019, the U.S. Food and Drug Administration (FDA) approved a combination of atezolizumab plus protein-bound paclitaxel (see Chemotherapy, above) for metastatic triple-negative breast cancer that tests positive for PD-L1 (see Diagnosis).

  • Pembrolizumab (Keytruda). This is a type of immunotherapy that is approved by the FDA to treat metastatic cancer or cancer that cannot be treated with surgery. These tumors must also have a molecular alteration called microsatellite instability-high (MSI-H) or DNA mismatch repair deficiency (dMMR) (see Diagnosis).

Different types of immunotherapy can cause different side effects. Common side effects include skin reactions, flu-like symptoms, diarrhea, and weight changes. Talk with your doctor about possible side effects for the immunotherapy recommended for you. Learn more about the basics of immunotherapy and immunotherapy and breast cancer.

Radiation therapy

Radiation therapy is the use of high-energy x-rays or other particles to kill cancer cells. A doctor who specializes in giving radiation therapy to treat cancer is called a radiation oncologist. The most common type of radiation treatment is called external-beam radiation therapy, which is radiation given from a machine outside the body. When radiation is given by placing radioactive sources into the tumor, it is called brachytherapy.

Radiation therapy may be used to shrink or slow tumor growth. It can also treat symptoms from the cancer, such as pain. Used by itself, or in combination with surgery, radiation therapy can also treat breast cancer that has spread to the brain. Several different types of radiation therapy are used to treat brain metastases, including whole brain radiation, stereotactic radiosurgery, and fractionated stereotactic radiotherapy.

  • Whole brain radiation therapy is directed at the entire brain.

  • Stereotactic radiosurgery is the use of a single, high dose of radiation given directly to the tumor to avoid harming the surrounding healthy tissues.

  • Fractionated stereotactic radiation therapy is similar to stereotactic radiosurgery but divided into small daily doses called fractions that are given over multiple days or weeks, in contrast to the 1-day radiosurgery.

A radiation therapy regimen, or schedule, usually consists of a specific number of treatments given over a set period of time. Doctors will set the schedule and radiation dose for breast cancer metastases based on a patient’s individual medical needs and prior use of radiation therapy.

Radiation therapy can cause general side effects, such as fatigue and skin problems. In addition to general side effects, other side effects may occur and depend on the type of radiation therapy given and where on the body it is directed.

Learn more about the basics of radiation therapy.


Surgery is the removal of a tumor and some surrounding healthy tissue during an operation. Surgery is not often used to treat metastatic breast cancer. However, doctors may recommend surgery to remove a tumor that is causing discomfort. Research continues on whether people who are first diagnosed with metastatic breast cancer live longer if the primary breast tumor is removed.

Surgery, used by itself or with radiation therapy, can be options to treat breast cancer that has spread to the brain. The goal is to shrink or temporarily get rid of the cancer in the brain. Usually, surgery of this type is done by a neurosurgeon, a specialist who operates on the head, brain, and central nervous system.

Before surgery, talk with your health care team about the possible side effects from the specific surgery you will have. Learn more about the basics of cancer surgery.

Summary of treatment options for metastatic breast cancer

HER2-negative breast cancer

Hormonal therapy is considered the standard initial treatment for HER2-negative metastatic breast cancer that is also hormone receptor-positive. However, chemotherapy, targeted therapy, or immunotherapy may also be given.

  • Chemotherapy. There is no specific type of chemotherapy recommended for this type of breast cancer. Many drugs are available, including those discussed under "Chemotherapy," above. The best chemotherapy option for each patient depends on several factors, including the previous treatments received, potential side effects, overall health, and the patient’s preference.

    Generally, chemotherapy should continue until the disease worsens if a patient is not experiencing unmanageable side effects. At some point, chemotherapy may no longer be able to control the cancer’s growth. When this happens, patients may choose to stop chemotherapy while continuing to receive palliative care.

  • Targeted therapy and immunotherapy. Targeted therapy or immunotherapy may also be an option depending on the type and features of the breast cancer. See Targeted therapy and Immunotherapy, above, for more details.

This information is based on ASCO’s recommendations on Chemo- and Targeted Therapy for Women with HER2 Negative (or unknown) Advanced Breast Cancer. Please note that this link takes you to a separate ASCO website.

HER2-positive breast cancer that has spread to parts of the body other than the brain

In general, HER2-targeted therapy is regularly added to treatment for HER2-positive breast cancer that has spread. The drugs used depend on the treatments already given and whether the cancer is hormone receptor-positive. The treatment recommendations for first-line, second-line, and third-line or higher treatment are listed below. A clinical trial may also be an option for treatment at any stage.

First-line treatment
  • Treatment is usually a combination of pertuzumab, trastuzumab, and a type of chemotherapy called a taxane.

  • If the cancer is hormone receptor-positive, treatment may be a combination of hormonal therapy plus HER2-targeted therapy with either trastuzumab or lapatinib. Hormonal therapy may also be given alone if the cancer has not spread widely, a patient has other health conditions that could be worsened with HER2-targeted therapies, or the cancer has recurred after a long time.

  • Chemotherapy is generally given for at least 4 to 6 months or until the patient experiences too many severe side effects, or the disease worsens. For patients with hormone receptor-positive cancer, HER2-targeted therapy and hormonal therapy usually continue after chemotherapy ends.

Second-line treatment
  • For patients with early-stage breast cancer who had the cancer spread during initial treatment with trastuzumab or return within 12 months after stopping treatment with trastuzumab, second-line treatment is used.

  • The preferred second-line treatment is the drug T-DM1.

Third-line or higher treatment
  • T-DM1 is a treatment option for patients who have not already received it.

  • Pertuzumab is also an option for patients who have not already received it. It is usually given in combination with trastuzumab.

  • For patients who have already received T-DM1 and pertuzumab, other options include trastuzumab deruxtecan, tucatinib with capecitabine and trastuzumab, lapatinib with capecitabine, other combinations of chemotherapy with HER2-targeted therapy, or hormonal therapy when appropriate.

This information is based on ASCO’s recommendations on Systemic Therapy for Patients With Advanced Human Epidermal Growth Factor Receptor 2–Positive Breast Cancer. Please note that this link takes you to a separate ASCO website.

HER2-positive breast cancer that has spread to the brain

The treatment of HER2-positive breast cancer that has spread to the brain often involves different types of radiation therapy. Sometimes, surgery and/or chemotherapy or targeted therapy may be used. Treatment in a clinical trial may also be an option.

In general, the treatment options available depend on the size and location of the tumor(s) in the brain, and the symptoms they are causing, as well as the patient’s general health.

Below is a general summary of when and how the above treatment options are used to treat brain metastases:

  • People with a single brain metastasis and good overall health generally receive surgery, followed by some type of radiation therapy. If the metastasis in the brain cannot be removed by surgery and the person is not having symptoms, stereotactic radiosurgery may be used.

  • People with 2 to 4 brain metastases generally receive stereotactic radiosurgery.

  • Treatment for people with cancer that has spread widely throughout the brain usually includes whole brain radiation therapy.

  • For people whose cancer in the brain is worsening even after receiving radiation therapy, additional treatment options depend on the initial treatment and include surgery, the types of radiation therapy discussed above, and/or a drug that can affect the whole body, such as chemotherapy or HER2-targeted therapy. In particular, the combination of tucatinib, capecitabine, and trastuzumab has been approved for treatment of patients with HER2-positive breast cancer that has spread to the brain.

  • People who also have metastatic HER2-positive breast cancer in parts of the body other than the brain usually continue their treatment regimen if the disease outside the brain is not worsening. If the disease is worsening, HER2-targeted therapy may be added/changed based on the recommendations for HER2-positive cancer that has spread to parts of the body other than the brain (see above).

This information is based on ASCO’s recommendations on Disease Management for Patients With Advanced Human Epidermal Growth Factor Receptor 2–Positive Breast Cancer and Brain Metastases. Please note that this link takes you to a separate ASCO website.

The next section in this guide is About Clinical Trials. It offers more information about research studies that are focused on finding better ways to care for people with cancer. You may use the menu to choose a different section to read in this guide.