Metastatic Breast Cancer Treatments

No cure for metastatic breast cancer exists, but treatment advancements are being developed.

Metastatic breast cancer—also known as stage 4 breast cancer—occurs when breast cancer spreads to other organs, such as bones, liver, brain, and lungs. It is incurable, and the most advanced form of the disease, but treatment options exist. Treatment for metastatic breast cancer is about prolonging and improving the quality of life, according to the American Cancer Society (ACS).

The five-year relative survival rate for metastatic breast cancer is much lower than that of localized cancers, per National Cancer Institute (NCI) data from 2012–2018. But these numbers don't take into account factors such as your age, overall health, and breast cancer type. Treatments are constantly improving.

Many metastatic breast cancer treatment options are available. Some—such as hormone therapy, targeted therapy, immunotherapy, and chemotherapy—use systemic (whole-body) drugs to fight breast cancer throughout the body. Surgery and radiation therapy target metastatic breast cancer locations, according to ACS.

Your treatment options differ depending on a few factors:

  • Certain genetic factors, such as having a BRCA1 or BRCA2 mutation
  • Where your breast cancer has spread (Cancer cells grow at different speeds depending on their location.)
  • Your menopausal status (whether your menstrual cycle has ceased or not), per the NCI
  • Your overall health and which treatments may bring you the least side effects

Below are eight treatment options available for metastatic breast cancer. Treatments may be combined, and palliative care can be helpful regardless of medications or therapies used.


Chemotherapy, or chemo, is a drug-based treatment that uses strong chemicals to kill cancer cells or slow their growth, according to the NCI. You can receive this therapy injected into the veins or by mouth, per the ACS. The medications affect the whole body, so chemotherapy can also kill healthy cells, which can result in side effects like:

Because of these intense drawbacks, chemo in the metastatic setting is often reserved for fast-moving cancers or cancers that have spread to the brain or liver. It's frequently paired with immunotherapy to treat metastatic triple-negative breast cancer.

Hormone Therapy

These drugs treat hormone receptor-positive (HR+) breast cancers or sometimes unknown hormone receptor cancers. HR+ refers to a characteristic of the cancer cells—it means the hormones progesterone, estrogen, or both, can attach to the cancer cells and stimulate the cells' growth, per the ACS.

Hormone therapy drugs block cancer's access to estrogen in various ways. A drug such as tamoxifen, for example, can block estrogen from stimulating cancer cell growth, per the National Library of Medicine MedlinePlus resource. Other drugs called aromatase inhibitors completely stop the production of estrogen in body tissues, per MedlinePlus.

Targeted Therapy

Targeted therapy attacks proteins on specific cancer cells with less damage to healthy cells than non-specific treatments such as chemotherapy, according to the NCI. Targeted therapy is often combined with cancer treatments such as chemo or hormone therapy. This improves the other treatments' effectiveness.

Targeted drugs can be administered as, per the ACS.:

  • Intravenous therapy (IV)
  • Injection
  • A pill

Side effects vary depending on cancer type but may include:

  • Severe diarrhea
  • Heart damage with corresponding heart disease symptoms, such as a fast heartbeat
  • Tiredness
  • Weakness
  • Rashes


This medication treatment works by spurring the immune system to fight breast cancer, according to the ACS. It treats certain types of metastatic breast cancers in combination with chemotherapy, per the NCI.

Immunotherapy can be effective because cancer cells can sometimes target immune cell proteins, preventing the immune system from responding to the disease. Drugs can restore these proteins so the immune system can fight the cancer cells, per the ACS.

Side effects of immunotherapy may include:

  • Fatigue
  • Cough
  • Nausea
  • Rash
  • Diarrhea
  • Constipation
  • Allergic reactions
  • Autoimmune issues (when the immune system mistakenly attacks healthy cells and tissues, per MedlinePlus

Radiation Therapy

Radiation therapy is a localized treatment that uses high doses of radiation to kill cancer cells, per the NCI. Think of it like a strong X-ray. Radiation is unlikely to destroy all cancer cells once they've spread, so healthcare providers prescribe this treatment less commonly for metastatic breast cancer, per the ACS. Radiation therapy is reserved for cases when a tumor is painful or for site-specific symptoms such as bone fractures or liver blood vessel blockages.

Unlike medication treatments, this therapy can target specific areas of the body where cancer has metastasized. Per the ACS, radiation can be:

  • External: This is when beams come from outside the body. This therapy can cause short-term symptoms, some around treatment sites, such as fatigue or skin issues; or long-term symptoms, including organ damage
  • Internal, also known as brachytherapy: This is when a device with radioactive pellets is placed in the affected tissue for a short time. Brachytherapy can cause redness, bruising, pain, or infection, also around the location of the treatment.


Surgery is less common to treat late-stage breast cancer because the goal of surgery is usually to remove most, if not all, cancerous cells, per the ACS. When cancer has metastasized, healthcare providers are unlikely to remove all cancer cells.

This treatment is more often reserved for painful cases of metastatic breast cancer—the same cases as radiation therapy, per the ACS. Radiation therapy may follow surgery, according to the NCI.

Clinical Trials

Research studies with human subjects look into potential treatment options for metastatic breast cancer. Participating in clinical trials helps researchers better understand how breast cancer works. Trials can provide you and others with new treatment options.

For example, one treatment in trials is high-dose chemotherapy with a stem cell transplant—replacing the stem cells (blood-forming cells) damaged by chemo with healthy stem cells, according to the NCI. The NCI keeps a database of clinical trials where you can search for their specific conditions.

Palliative Care

The goal of palliative care is to improve quality of life and manage symptoms of people living with chronic or serious illnesses, according to the National Institute on Aging (NIA). The oncology team often co-manages care with the palliative medicine team.

The palliative care team can consist of:

  • Specialist doctors
  • Nurses
  • Social workers
  • Nutritionists
  • Chaplains

Together, your team can manage pain and help you make healthy choices about your treatments and lifestyles. It's a more holistic type of medical care. Working with a palliative care team in addition to a cancer treatment team can improve end-of-life care for people with metastatic breast cancer, according to an October 2017 study published in the journal Breast Cancer Research and Treatment.

The five-year survival rate for metastatic breast cancer has increased significantly, per a May 2017 paper published in the journal Cancer Epidemiology, Biomarkers and Prevention. With the advancement of different treatment options, there's hope for people with the disease to live longer with more manageable symptoms.

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