What Is Metastatic Breast Cancer?

Young woman holding a Breast Cancer Awareness Ribbon

Metastatic cancer is cancer that has spread to another site in the body — often a distant organ. It is the most advanced stage of cancer, also called stage 4.

In the case of breast cancer, the most common sites for distant metastases are the bones, lungs, liver, skin and brain. Cancer is treated according to where it began, even when it moves into other organs. So breast cancer that has spread to the lungs is not lung cancer, but metastatic breast cancer. It is treated using breast cancer therapy, regardless of where it has spread.

Recent research estimates more than 150,000 women in the United States currently are living with metastatic breast cancer. Most of the time, this cancer develops months to years after a woman was initially treated for early-stage breast cancer. In the U.S., only about 6% of women have metastatic disease when they are first diagnosed.

While metastatic breast cancer is incurable, recent advances in cancer therapy and supportive care have improved the prognosis of the disease and patients’ quality of life during treatment. The survival rate for metastatic breast cancer is highly individual and depends very much on how the cancer responds to treatment. Average survival with metastatic breast cancer is around two years, but more than a quarter of patients have lived with the disease for over five years.

What Are the Signs That Breast Cancer Has Metastasized?

Metastatic breast cancer can produce different symptoms, depending on where it has spread. If it involves the bones, you may develop pain in the back, neck or ribs. If it involves the lungs, you might experience shortness of breath or a cough that does not clear up over time. Other symptoms that a cancer has spread may include unintentional weight loss, lymph nodes or skin lesions that can be felt, or new, severe headaches.

What Are the Treatments for Metastatic Breast Cancer?

Treatment is based on many different factors, including tumor characteristics and past therapy.

Oncologists treating metastatic breast cancer will choose from a variety of treatment options, which depend largely on the biomarkers expressed by the tumor, including hormone receptors, HER2 or PDL-1. Less commonly, certain types of abnormal inherited genes, such as BRCA may guide treatment decisions. Treatments may be given by mouth, injected or administered by an infusion. In addition, radiation can be given to treat certain problematic areas.  Additional medications are often given to strengthen the bones and help maintain normal calcium levels.

At Roswell Park, we treat metastatic breast cancer with a multidisciplinary team approach, calling on experts in all the fields of breast cancer care. We participate in clinical trials to find better ways to diagnose and treat the disease, and help patients live longer with a higher quality of life.

Treatment for metastatic breast cancer centers on two goals: prolonging survival and treating cancer-related symptoms to improve patients’ function and quality of life. We use many different options targeted to the tumor and the individual, including:

  • Endocrine or anti-estrogen therapy, often administered in combination with medications that help stop cancer cell growth
  • Monoclonal antibodies to target cancers that overexpress HER2, such as trastuzumab (Herceptin) and pertuzumab (Perjeta)
  • Immunotherapy in combination with chemotherapy for triple-negative breast cancer that expresses PDL-1
  • Chemotherapy, administered either orally or by infusion
  • Radiation therapy to treat distant sites
  • Gamma Knife radiosurgery to treat metastases to the brain
  • Clinical trials of the latest drugs and other treatments, such as immunotherapy. Through clinical trials, Roswell Park patients were some of the first to benefit from Herceptin and other FDA-approved treatments. Patients should ask their oncology team about available clinical trials.
  • Bone-strengthening treatments using agents such as zoledronic acid (Zometa) or denosumab (Xgeva) can relieve the effects of cancer that has spread to the bone.

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Other Therapies for Metastatic Breast Cancer

In addition to anti-cancer treatments, metastatic breast cancer patients should take advantage of all the specialists who can help improve their quality of life during treatment. Roswell Park’s supportive care specialists — including experts in pain and palliative care, psychologists and physical therapists — can help patients maintain and improve function, well-being and independence during cancer therapy. We also provide rehabilitation medicine, including physical and occupational therapy, to help patients strengthen and maintain their bodies during and after treatment.