What Is Metastatic Breast Cancer? Symptoms, Causes, Treatments, and More

Treatment options for metastatic breast cancer will depend on a variety of issues, according to the American Society of Clinical Oncology, including:

• Where the cancer has spread in your body
• The tumor’s hormone receptor and HER2 status
• The tumor’s gene mutations
• Symptoms
• The treatments received in the past
• Gender
• Menopausal status
• Overall health

While treatment for metastatic breast cancer is not expected to cure the disease, it can extend survival and improve quality of life.

Hormone Therapy

Hormone therapy may be a treatment option for tumors that test positive for estrogen or progesterone receptors. The treatment works by lowering levels of these hormones in your body or blocking them from reaching cancer cells. This prevents the tumors from using the hormones to fuel their growth.

There are many hormone therapies available. Doctors commonly recommend tamoxifen, an aromatase inhibitor, or fulvestrant (Faslodex) for breast cancer that has come back or spread, according to the American Cancer Society.

Chemotherapy

Chemotherapy involves using drugs to kill cancer cells. Most of the time, chemotherapy drugs are given one at a time for advanced cancer, instead of in combination with each other, as they are in earlier-stage disease.

The American Cancer Society lists the following chemo medicines as possible treatments for metastatic breast cancer:

• Taxanes, such as paclitaxel (Taxol), docetaxel (Taxotere), and albumin-bound paclitaxel (Abraxane)
• Anthracyclines, such as doxorubicin (Adriamycin), liposomal doxorubicin (Doxil), and epirubicin (Ellence)
• Platinum agents (Cisplatin, carboplatin)
• Ixabepilone (Ixempra)
• Eribulin (Halaven)
• Vinorelbine (Navelbine)
• Capecitabine (Xeloda)
• Gemcitabine (Gemzar)
• Antibody drug conjugates (ado-trastuzumab emtansine [Kadcyla], fam-trastuzumab deruxtecan [Enhertu], sacituzumab govitecan [Trodelvy])

Targeted Therapy

Targeted therapies focus on blocking specific proteins on breast cancer cells that help them grow and spread. Different tumors have different targets. That’s why doctors perform tests to identify the gene mutations or proteins in your tumor.

The type of targeted therapy your doctor recommends will depend on your tumor’s biology. For instance, if your tumor tests positive for HER2, targeted treatments may be used to block the HER2 protein that promotes breast cancer cell growth.

There are many types of targeted therapies. According to Memorial Sloan Kettering Cancer Center, some newer targeted medicines commonly used in breast cancer are:

Immunotherapy

Immunotherapy involves using the body’s own immune system to fight cancer. The following immunotherapies are used to treat metastatic breast cancer, according to the American Society of Clinical Oncology:

Surgery

Surgery isn’t commonly used to treat metastatic breast cancer, but it can be an option in certain cases. For example, doctors may remove a tumor that’s causing discomfort or other problems. Or, if breast cancer has spread to the brain, surgery may be used to shrink the cancer.

Radiation

Radiation involves using high-energy X-rays or other particles to kill cancer cells. The treatment may help shrink tumors or improve symptoms. It may also be used for breast cancer that has spread to the brain.

Clinical Trials

Clinical trials are research studies that look for new ways to treat or prevent different diseases. People with metastatic breast cancer may benefit from participating in a clinical trial by receiving certain therapies that aren’t available otherwise. Talk to your doctor about the pros and cons of joining a clinical trial.