Hormone therapy

Very effective treatment for metastatic breast cancer, but only in women whose tumors have positive estrogen and/or progesterone receptors. This type of treatment controls cancer growth very well with few side effects. It works by preventing estrogen and progesterone from allowing the cancer cells to multiply.

Chemotherapy

Chemotherapy can kill cancer cells and stop tumor growth. Chemotherapy for metastatic breast cancer can be much less aggressive than early-stage chemotherapy and is aimed at controlling the tumor while having a minimal impact on the patient's life. Chemotherapy medications may be given through the vein (intravenously) or by mouth (orally).

In women with metastatic breast cancer that is hormone receptor negative and HER2 negative, treatment may include: Chemotherapy and immunotherapy

Targeted therapy

Some types of breast cancer contain cells that overexpress certain proteins (or that have gene changes) that can cause the cancer to grow more aggressively and/or be resistant to chemotherapy or endocrine therapy. Targeted therapy can "target" those proteins (or the genetic changes) in these cells and thus move in to kill the cancer cells. Targeted therapies are often given along with hormone therapy to treat advanced breast cancers that are driven by estrogen (estrogen-receptor positive), or combined with chemotherapy in breast cancers that are positive for HER2, as these can reverse resistance to hormone therapy or synergize the chemotherapy and help it work more effectively.

PARP inhibitors work by preventing cancer cells from repairing themselves, allowing them to die. PARP inhibitors preferentially kill cancer cells at the BRCA mutation over normal cells. Your doctor may recommend a PARP inhibitor for maintenance therapy after initial therapy or for treating recurrence.

Antibody–drug conjugates or ADCs are a class of biopharmaceutical drugs designed as a targeted therapy for treating cancer. Unlike chemotherapy, ADCs are intended to target and kill tumor cells while sparing healthy cells. Biopharmaceutical drugs contain substances that have been created by using living cells or organisms and is a new form of targeted treatment. PARP inhibitors are a type of targeted therapy that helps repair DNA damage in cells. PARP inhibitors work by preventing cancer cells from repairing, allowing them to die. Inhibitors of PARP preferentially kill cancer cells in BRCA-mutation cancer cell lines over normal cells. Your physician may recommend a PARP inhibitor if you have a BRAC mutation.

Immunotherapy

PDL1 is a protein that helps keep immune cells from attacking nonharmful cells in the body. Normally, the immune system fights foreign substances like viruses and bacteria, and not your own healthy cells. Some cancer cells have high amounts of PDL1. This allows the cancer cells to "trick" the immune system, and avoid being attacked as foreign, harmful substances.

If your cancer cells have a high amount of PDL1, you may benefit from a treatment called immunotherapy. Immunotherapy is a therapy that boosts your immune system to help it recognize and fight cancer cells. Immunotherapy has been shown to be very effective in treating certain types of breast cancers.

Bone Modifying Agents

Bone modifying agents, including bisphosphonates and denosumab, are often used when breast cancer has spread to the bones. These drugs can strengthen bones and reduce the risk of pain, fractures and breaks. Bisphosphonates may also help prevent thinning of the bone (osteoporosis).

Radiation therapy

Given to reduce tumor size, relieve pain and ease symptoms. Often used for bone metastases.

Surgery

Rarely used to treat metastatic breast cancer. Since the cancer has spread to multiple locations, it is much harder to remove surgically. Surgery may be used to ease symptoms, and sometimes is used to remove the primary tumor in patients who have had excellent response to chemotherapy, or in patients with stable metastatic disease.

Genomic Testing

For patients with metastatic breast cancer your doctor will generally approach you about conducting a genetic testing of your tumors or blood. These tests are different from testing your normal cells for examples, like BRCA, to understand the risk of development of the breast cancer. Instead, these tests are conducted to lead physicians in determining if you are appropriate for a specific targeted therapy. These treatments are generally tested in clinical trials. It is essential to discuss with your doctor whether you are revelent for your tumor to be tested for genomic testing.