With stage IV, the breast cancer has spread to other parts of your body. Often the bones, brain, lungs, or liver are affected. Because multiple areas may be involved, focused treatments like surgery or radiation alone may not be enough.
Treatment of stage IV doesn’t cure the disease. But by shrinking the cancer, it can often slow it down, help you feel better, and let you live longer. Patients with stage IV breast cancer may live for years, but it’s usually life-threatening at some point.
Most of the more than 232,000 cases of breast cancer that will be diagnosed in the United States this year are not due to a faulty gene passed down through families. As with most other cancers, they happen because of genetic mutations that happen as we age.
But about 15% of women with breast cancer have at least one relative who has also had the disease, and 5% to 10% have specific inherited mutations in one of two genes that have been linked to breast cancer, known as BRCA1 and BRCA2.
Chemotherapy is often the main treatment for this stage. It can slow down the growth of the cancer. It’s often used in combination with hormone therapy.
You can get chemo several different ways. You may take pills or liquids, but often the drugs are put right into your veins. Depending on the type of treatment, it may be given in cycles that allow your body breaks in between.
Hormone therapy can be helpful for women with hormone receptor-positive cancers. That means the cancer needs hormones to grow. In these women, medications can prevent the tumor from getting the hormone. These drugs include tamoxifen for all women and anastrozole (Arimidex), exemestane (Aromasin), and letrozole (Femara) for postmenopausal women. Letrozole is sometimes taken with palbociclib (Ibrance), which slows cancer cell growth.
Women who haven't reached menopause may consider having their ovaries removed to stop them from making hormones that help cancer grow.
Targeted therapy is a newer treatment. About 20% of women with breast cancer have too much of a protein known as HER2, and it makes the cancer spread quickly. Women with HER2-positive cancer that has spread often take trastuzumab (Herceptin). It stops the protein from making the cancer cells grow. It may also boost your immune system, giving it the strength to fight the cancer itself. Often, people combine this treatment with chemotherapy. Sometimes doctors prescribe another medication, pertuzumab (Perjeta), to take along with trastuzumab and docetaxel (Taxotere).
After other treatments, your doctor may prescribe lapatinib (Tykerb) to treat HER2-positive advanced breast cancer. People who were previously treated with trastuzumab and a class of chemotherapy drugs called taxanes may also take ado-trastuzumab emtansine (Kadcyla).