The main goals of metastatic breast cancer treatment are to ensure that you have the: Best and longest quality of life possible Fewest possible side effects from the cancer and its treatment The types of systemic therapies used for metastatic breast cancer include: Hormonal therapy Chemotherapy Targeted therapy Options for hormonal therapy: Tamoxifen. Tamoxifen is a drug that blocks estrogen from binding to breast cancer cells. The treatment is an option for both premenopausal and postmenopausal women. Aromatase inhibitors decrease the amount of estrogen made by tissues other than the ovaries in women who have gone through menopause by blocking the aromatase enzyme. 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 or an AI. Fulvestrant. Fulvestrant is a selective estrogen receptor downregulator (SERD). That means it binds to the estrogen receptors, blocking the ability of estrogen to attach to these receptors. Fulvestrant is a medication for postmenopausal women only. 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. Examples of monoclonal antibodies used for breast cancer include trastuzumab, pertuzumab, and TDM-1. Small molecule inhibitors. Small molecule inhibitors are drugs designed to specifically target parts of a cancer cell that contribute to its growth and survival. Targeted therapy for metastatic HER2-positive breast cancer Trastuzumab. For metastatic breast cancer, trastuzumab can be given in combination with different types of chemotherapy or with hormonal therapy. Pertuzumab. 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. Ado-trastuzumab emtansine or T-DM1. 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. Lapatinib. 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. 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. Targeted therapy for metastatic hormone receptor-positive, HER2-negative breast cancer Palbociclib. 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. Abemaciclib. 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 as alone as a treatment. Everolimus. Everolimus is used with the AI exemestane for ER-positive, HER2-negative metastatic breast cancer that has grown despite treatment with another AI. Targeted therapy for people who have a BRCA1 or BRCA2 gene mutation Olaparib. This oral drug may be used for patients with metastatic HER2-negative breast cancer and a BRCA1 or BRCA2 gene mutation who have previously received chemotherapy. It is a type of drug called a PARP inhibitor, which destroys cancer cells by preventing them from fixing damage.