What is Metastatic Breast Cancer?

Metastatic breast cancer is breast cancer that has spread to more than one area. You may have also heard it referred to as stage four (IV) breast cancer or advanced breast cancer.

Breast cancer is the second most common cause of cancer death in women, and the majority of these deaths come from metastatic breast cancer. Therefore, it is vital to detect breast cancer at its earliest stages when it is most treatable and beatable.

For decades, we’ve partnered with area women, helping them through annual wellness screenings, exams, and referrals for mammograms when needed.

In this article, we’ll take a closer look at what is metastatic breast cancer and the various stages of breast cancer.

What Is Metastatic Breast Cancer?

Cancer is said to have metastasized when it has spread to more than one part of the body. Metastatic breast cancer occurs when cancer that was originally discovered in the breast spreads to other areas—most commonly to the bones, liver, lungs and brain. Note that even though the cancer may have spread to other parts of the body, it is still referred to as breast cancer.

What Is Metastatic Breast Cancer: Can It Be Cured?

While metastatic breast cancer cannot be cured, help is available for patients to continue to live well and without pain.

What Is Metastatic Breast Cancer: Facts You Should Know

  • According to the Cleveland Clinic, there are an estimated 170,000 people in the U.S. who are living with metastatic breast cancer.
  • Men as well as young women can be diagnosed with metastatic breast cancer.
  • There are several different subtypes of metastatic breast cancer, and this is based upon what is the source of the cancer’s growth.
  • 1-in-3 women diagnosed with early-stage breast cancer will develop metastatic breast cancer.

What Causes Metastatic Breast Cancer?

Most often, this type of cancer is caused when cancer treatment doesn’t destroy all cancer cells or cancer is not discovered early. Dormant, hidden cells are sometimes undetectable and then grow and spread. Research is still ongoing as to why these cells spread.

What Are the Stages of Breast Cancer?

There are 4 basic stages of breast cancer. We’ll take a look at each of them.

Breast cancer is graded in stages 0 through 4. The higher the number, the more the cancer has spread. There may also be subcategories within each stage.

In addition, a letter is often assigned (T, N, and M). These letters deal with the size of the tumor, whether or not lymph nodes are involved, and whether or not it has metastasized (spread to other parts of the body).

Stage 0 Breast Cancer

This stage describes breast cancer that is localized mainly to the milk ducts. It’s also called ductal carcinoma in situ. In stage 0, the breast cancer has not spread to other parts of the body.

Stage 1 Breast Cancer

In this stage, a cancer has been found that is less than two centimeters across. The cancer has not spread anywhere and there is no involvement from the lymph nodes.

Stage 2 Breast Cancer

In stage 2 breast cancer, the cancer has spread to other areas. To be classified as stage 2, the breast cancer must have one of the following:

  • A tumor less than two centimeters that has spread to the lymph nodes under the arm.
  • A tumor that is between two and five centimeters, which may or may not have spread to the lymph nodes.
  • A tumor larger than five centimeters that has not spread to the lymph nodes.

Stage 3 Breast Cancer

You may have heard this referred to as “locally advanced breast cancer.” This means that, in addition to a cancerous tumor in the breast, there are also cancerous lymph nodes that are adhering to each other or surrounding tissues.

It may also include a tumor of any size that has spread to the chest wall, skin or lymph nodes beneath your breast or inside your chest.

Stage 4 Breast Cancer

This is also called metastatic breast cancer, and in it a tumor has spread to other areas of the body such as the bones, liver or brain.

Treatments for breast cancer depend upon the stage of the cancer and may include surgery, chemotherapy and radiation.

Women’s Health Services at Cary Medical Group

At Cary Medical Group, we’ve been providing compassionate care for women of the Cary and Triangle area for decades. Our reputation for excellence and state-of-the-art innovation have made us the provider of choice for the area.

As part of our women’s health services, we offer:

  • Pap smears and breast exams, as part of annual exams
  • Manage pre/post menopausal symptoms
  • Birth control (consultation and prescriptions)
  • Treatment for UTIs (urinary tract infections)

See why women across the Triangle have trusted us with their care. Schedule a wellness appointment with us today.


For more than 25 years, Cary Medical Group has served as the Triangle area’s premier internal medicine provider. We tailor our treatments to provide the finest personalized health care available for each stage of your adult life. Contact us to schedule an appointment.