What Is Stage 4 Breast Cancer?

“Stage 4” refers to cancer that has spread beyond the original site. Often, in Stage 4 breast cancer, cancer cells have spread to distant lymph nodes, the brain, liver, lungs, or bones. Other terms you may have heard for this same situation are “metastatic” or “metastasized,” “invasive,” and “advanced.” Stage 4 breast cancer is considered to be incurable, but many treatment options exist that can result in living longer with a good quality of life.

Treatment Options: An Overview

Because there are many types of breast cancer, there are many types of treatment options. Not every treatment is right for every patient, but here is a list of available options:

  • chemotherapy
  • radiation therapy
  • surgery
  • hormone therapy
  • targeted therapy
  • clinical trials
  • pain management


Chemotherapy uses one or more drugs to either kill cancer cells or slow their growth. Given either orally or through an IV, the drugs travel through the bloodstream. In this way, the drugs can target not only the original site of the cancer, but also any cancer cells that have spread. Unfortunately, chemotherapy drugs affect other cells in the body besides the cancer cells. Once chemotherapy is completed, however, the side effects will subside.

Radiation Therapy

Radiation therapy uses strong X-rays or other forms of radiation either to destroy cancer cells or keep them from growing. The radiation can either be focused on the area where the cancer is growing, or inserted in or near a tumor with a needle, tube, or pellet. Radiation is most useful in situations where it is known precisely where the cancer has spread.


Surgical options for stage 4 breast cancer depend on where and how the cancer has spread. A well-defined tumor in, for example, the lung, could be removed through surgery. Cancerous lymph nodes may also be removed. In some cases, the ovaries may even be removed. This lowers estrogen levels in the body, reducing the risk of further metastasis (spreading) of hormone receptor-positive cancers.

Hormone Therapy

Hormone therapy is used in cases where the cancer is hormone receptor-positive. This means that estrogen or progesterone produced in the body is facilitating the cancer to grow and spread. Tamoxifen is one drug that blocks the estrogen receptors in breast cancer cells, which stops the cells from growing and dividing. Other drugs, called aromatase inhibitors (AIs), stop estrogen production and lower estrogen levels in the body. Common AIs include anastrozole (Arimidex), letrozole (Femara), and exemestane (Aromasin). 

Targeted Therapy

Targeted therapies are used to combat very specific types of cancer cells. One example is HER2-positive breast cancer. This is an aggressive type of cancer that has elevated levels of a specific protein that helps cancer cells grow. In this case, specially developed drugs like trastuzumab (Herceptin) are used to target this protein and slow (or eliminate) the growth of the cancer. Targeted therapies are often used in combination with other treatments, like chemotherapy.

Clinical Trials

Clinical trials are research studies using new drugs, or new combinations of drugs, that have been approved for use in human research. Trials are conducted when researchers believe that a drug has the potential to be better than current standard treatment. While it can be scary to think about being part of a research study, it’s important to remember that each one of today’s standard treatments was once part of a clinical trial.

Pain Management

Pain management is an important component of any cancer treatment regimen. While the treatments described above may help prolong your life, pain management is what will allow you a higher quality of life. There are many options for pain management, depending on the source and type of pain. Be sure to talk to your doctor about your pain, sooner rather than later, so that proper steps can be taken to help you feel better.