Breast Cancer: What Does 'Metastatic' Mean?

Video Transcript

Jane Meisel, MD <br>Winship Breast Oncologist<br>Pond5.<br>AudioJungle.

[MUSIC PLAYING] JANE MEISEL: When you hear people talk about metastatic breast cancer, what that is, is basically breast cancer that has spread outside of the breast or the surrounding lymph nodes, where it initially starts, to other organs. So common places where breast cancer can spread include the skin, the bones, the liver, lymph nodes elsewhere in the body, lung, and then sometimes, brain. So breast cancer that's spread to those areas is treatable, but typically not curable. You know, you think about early stage breast cancer being a small lump in the breast often found on a mammogram. Stage 4 breast cancer is breast cancer that is often detected either by imaging, like CT scans, or because a patient comes in with symptoms that then lead to a diagnosis. One of the things that we think happens is that it just takes one or two cells that break off from the initial tumor that's formed in the breast that then get into the bloodstream and then go to other places to sort of set up shop and grow. And that's part of the reason why for patients who have curable breast cancer, we often, in addition to doing surgery or radiation therapy to treat the breast cancer locally, we're giving some sort of systemic therapy, meaning treatment that goes either through the IV or in pill form to treat cancer cells, not just in the breast, but anywhere that the blood stream goes so that you're hopefully catching those cells before they get out into the bloodstream and then start to cause problems elsewhere. So prognosis for metastatic breast cancer varies widely based on a number of different things. You know, the goal is to make metastatic breast cancer into a chronic illness. We hope the research continues to outpace their disease so that they'll be on one line of treatment for one to two or even three years where the cancer stays stable or shrinks or doesn't grow. And then at the time when the cancer does grow again, we start a new line of treatment. For others, it takes a more aggressive course. And for almost all patients, it does shorten their life in some way, shape, or form.

Metastatic breast cancer means the cancer has spread from your breast to distant organs such as your bones, lungs, or other parts of your body.

No matter where the cancer spreads, it's still called "breast cancer." For example, breast cancer that has spread to your lungs is called "breast cancer," not "lung cancer." Your doctor will still treat it like breast cancer.

Doctors sometimes use the term "advanced breast cancer" or "stage IV breast cancer" to describe cancer that has spread. Stage IV is the most advanced stage of the disease.

If your cancer has metastasized (another way to say "spread"), you might wonder what to expect. Metastatic breast cancer isn't curable, but it is treatable. Several treatments can slow its progress, relieve your pain and other symptoms, and help you live longer.

How Common Is It?

About 155,000 women in the United States live with metastatic breast cancer. Men can have metastatic breast cancer too, but it's rare.

Only 6% to 10% of women with breast cancer are diagnosed at stage IV. About 20% to 30% of women are diagnosed with an early-stage breast cancer, and then the cancer spreads.

How Breast Cancer Spreads


Cancer cells can travel from your breast to other organs through your lymph system or bloodstream. Often, breast cancer spreads when it gets into the lymph nodes under your arms (called axillary nodes). From there, it enters the lymphatic system, a collection of nodes and vessels that are part of your body's immune system.

Once the cancer has reached other organs, it forms new tumors.

Metastatic breast cancer can also start months or years after you've finished treatment for an earlier-stage cancer. This is called a distant recurrence.

Treatments like surgery, radiation, and chemotherapy are good at removing or killing cancer cells. But sometimes, they can leave a few cancer cells behind. Even a single cancer cell can grow into a new tumor that spreads to other parts of your body.

Where Breast Cancer Tends to Go

Breast cancer most often spreads to these organs:

Bones. Breast cancer travels to the bones through the bloodstream. The ribs, spine, pelvis, and long bones of the arms and legs are the most common bones that breast cancer reaches. Bone pain and tenderness are signs the cancer is in your bones. Breast cancer cells can also get into bone marrow -- the spongy tissue inside bones where blood cells are made.

Liver. Cancer cells can get into the liver through the bloodstream because the liver filters the blood.

Lungs. The lungs are another common site for metastatic breast cancer to spread because your blood flows through them to pick up oxygen.

Brain. Any type of breast cancer can spread to the brain, but HER2-positive and triple-negative cancers are most likely to reach this organ. Signs of cancer in the brain include headaches, seizures, vision changes, and dizziness.

WebMD Medical Reference Reviewed by Brunilda Nazario, MD on October 23, 2020


SOURCES: "Where in the body does breast cancer usually spread?"

American Cancer Society: "Treatment of Stage IV (Metastatic) Breast Cancer," "Understanding advanced cancer, metastatic cancer, and bone metastasis." "Recurrent & Metastatic Breast Cancer."

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Cancer Epidemiology, Biomarkers & Prevention: "Estimation of the number of women living with metastatic breast cancer in the United States."

Fred Hutchinson Cancer Research Center: "Living with stage 4."

Metastatic Breast Cancer Network: "Incidence."

Susan G. Komen: "Treatments for Metastatic Breast Cancer."

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