Breast Cancer Metastatic
Metastatic breast cancer is breast cancer that has spread beyond the breast and nearby lymph nodes to other parts of the body. While there is currently no cure, many people are living longer than ever before thanks to advances in treatment, and it is possible to live well with this disease for many years.
Table of contents
- What is Metastatic Breast Cancer?
- Symptoms of Metastatic Breast Cancer
- How Breast Cancer Spreads
- Where Metastatic Breast Cancer Can Spread
- Diagnosing Metastatic Breast Cancer
- Treatment Options
- Living with Metastatic Breast Cancer
What is Metastatic Breast Cancer?
Metastatic breast cancer, also called advanced breast cancer or Stage IV breast cancer, is cancer that has spread from the breast to other areas of the body[1][2]. The most common sites where breast cancer spreads are the bones, lungs, liver, and brain[2][3].
When breast cancer spreads to another part of the body, the cancer cells in the new location are still breast cancer cells, not cells from the organ where they have settled. For example, breast cancer that has spread to the bones is still breast cancer and is treated with breast cancer drugs, not treatments for cancer that began in the bones[11].
Most people with metastatic breast cancer developed it after being treated for an earlier stage of breast cancer. This is called metastatic recurrence or distant recurrence. Nearly 30% of women diagnosed with early-stage breast cancer develop metastatic disease[3]. About 20% to 30% of women with early-stage cancer later develop metastatic breast cancer[2].
However, some people have metastatic breast cancer when they are first diagnosed. This happens in about 6% of women and about 10% of men in the United States[11]. When metastatic breast cancer is present from the beginning of a person’s diagnosis, it is called de novo metastatic breast cancer[3][11].
The most recent data shows around 170,000 women in the United States are living with metastatic breast cancer[2]. In 2017, researchers estimated that more than 150,000 women in the United States were living with metastatic breast cancer[16]. Men can also develop metastatic breast cancer, though it is much less common[3].
Symptoms of Metastatic Breast Cancer
The symptoms of metastatic breast cancer depend on where the cancer has spread in the body[2][6]. Not every physical change means the cancer is getting worse. For example, fatigue is a common symptom of metastatic cancer, but it is also a side effect of common cancer treatments like chemotherapy (drugs that destroy cancer cells) and radiation[2].
General symptoms that may occur with metastatic breast cancer include fatigue, persistent feeling of being unwell, loss of appetite, unexplained weight loss, and nausea[4][6]. Sometimes people with metastatic breast cancer do not have any notable changes or symptoms[6].
Specific symptoms depend on where the cancer has spread:
Bones: Sudden joint pain or bone pain that does not go away, bones that break more easily, numbness or muscle weakness in the arms and legs, and swelling[2][3]. Roughly 70% of all patients living with advanced breast cancer have bone metastases[6].
Brain: Worsening headaches or pressure in the head, vision problems such as double vision, blurred vision, or seeing flashes of light, seizures, nausea and vomiting, and behavior or personality changes[2][6].
Lungs: Cough that will not go away, shortness of breath or difficulty breathing, chest pain, and frequent chest infections[2][3][6].
Liver: Jaundice (yellowing of the skin and eyes), itchy skin or rash, stomach pain, loss of appetite, nausea and vomiting, and elevated liver enzymes[2][6].
It is important to talk to your healthcare provider if you notice any new or persistent symptoms, even if you are unsure whether they are related to the cancer[2].
How Breast Cancer Spreads
Cancer spreads through a process called metastasis. This happens when cancer cells break away from the original tumor in the breast and travel to other parts of the body[3]. These cells travel through the bloodstream or the lymphatic system (the network of lymph nodes and vessels that removes bacteria, viruses, and waste from cells)[3].
Most metastatic breast cancer is recurrent cancer, meaning it came back after treatment[2]. Breast cancer typically comes back when treatment does not destroy all cancer cells. Even surgery to remove a cancerous tumor is not always 100% effective. Cancer cells can move into nearby tissue, lymph nodes, or the bloodstream before the surgery[2].
These weakened cancer cells can remain in the body after treatment. The immune system usually detects and destroys traveling cancer cells. However, if the cells manage to settle in other organs or tissue and avoid being destroyed, they can develop into metastatic tumors[4]. Over time, the cells get stronger, start to grow and multiply again, and may travel through the bloodstream and lymphatic system to other areas of the body[2].
Breast cancer cells may start forming new tumors right away, or they can lie dormant for months or years after the original diagnosis and treatment[2]. Doctors do not know exactly why some cancer cells leave the original tumor, why some continue to grow while others do not, or why some metastatic tumors cause symptoms early on while others do not until years later[4].
Where Metastatic Breast Cancer Can Spread
Breast cancer can spread to almost any part of the body, but it most commonly spreads to the bones, lungs, liver, and brain[2][3][6]. The targeting of specific organs by cancer cells is probably regulated by chemical attractant factors and adhesion molecules produced by the target organ, along with cell-surface receptors expressed by the tumor cells[6].
The bones are the most common site for breast cancer to spread. Metastatic disease to the bone causes severe, progressive pain and, less commonly, fractures, redness over the affected bone, and swelling[6].
When breast cancer spreads to the liver, it can cause jaundice, elevated liver enzymes, abdominal pain, loss of appetite, nausea, and vomiting[6]. Metastatic breast cancer in the lungs or the tissue lining the lungs can cause chronic cough, difficulty breathing, abnormal chest X-ray results, and chest pain[6].
Metastatic breast cancer to the brain causes persistent, progressively worsening headache, visual changes, seizures, nausea or vomiting, vertigo, and behavioral and personality changes[6].
Diagnosing Metastatic Breast Cancer
Many women notice changes themselves, or a doctor might notice them during an examination[4]. If you have a previous diagnosis of breast cancer and present with findings suspicious for recurrent metastatic disease, your doctor may recommend a diagnostic biopsy, especially if there has been a long disease-free interval[10].
A biopsy (removal of a small tissue sample for examination) is helpful in excluding benign processes that frequently resemble metastases and in ruling out the development of other cancers[10]. The tissue can also be tested for certain markers, such as estrogen receptors, progesterone receptors, and HER2, to assist in treatment decisions[10].
Diagnostic tests and staging procedures are directed by the organ sites most frequently involved in metastatic breast cancer and by patient signs and symptoms. Documentation of initial metastatic sites is helpful in treatment planning and in later assessment of response to treatment[10].
Common imaging tests used to diagnose metastatic breast cancer include computed tomography (CT) scans (detailed images created using X-rays and computer processing), magnetic resonance imaging (MRI) (images created using magnets and radio waves), positron emission tomography (PET) scans (images showing how tissues and organs are functioning), bone scans, and X-rays. Blood tests may also be used to look for signs of cancer spread[10].
Treatment Options
Healthcare providers cannot cure metastatic breast cancer, but they can recommend treatments that improve quality of life and help people live as long as possible[2]. More people are living longer with metastatic breast cancer as medical researchers find new ways to treat the disease[2].
The aim of treatment is to stop the cancer from getting worse for as long as possible and to relieve symptoms[4]. While there is no cure for metastatic breast cancer, treatment may control it for a number of years[3]. If one treatment stops working, there is almost always another to try[3]. The cancer can be active sometimes and then go into remission at other times[3].
Treatment decisions depend on where in the body the cancer has spread, the cancer’s characteristics (such as hormone receptor status and HER2 status), any cancer treatments you have had in the past, and your overall health[8][12]. Most treatment for metastatic breast cancer uses systemic medicines, which treat cancer throughout the entire body[8].
Hormone therapy works by lowering the levels of estrogen or progesterone in the body, or blocking their effects. It is offered for hormone receptor-positive breast cancer and is commonly given when the cancer has spread to the bones and soft tissues, or when it has spread to internal organs but is not causing symptoms[12].
Chemotherapy uses anti-cancer drugs to destroy cancer cells. It is given for metastatic, hormone receptor-negative breast cancer. It is also offered for hormone receptor-positive breast cancer that has spread to internal organs and is causing symptoms[12]. Chemotherapy drugs are often used alone to treat metastatic breast cancer because a single drug causes fewer side effects than a combination of drugs[12].
Targeted therapy drugs work by targeting the differences in cancer cells that help them grow and survive. For metastatic breast cancer, targeted therapy is often given in combination with chemotherapy or hormone therapy[12]. Some targeted therapies only work if the breast cancer cells have certain receptors or genetic changes[12].
Immunotherapy works by helping the immune system recognize and attack cancer cells. It may be offered for certain types of metastatic breast cancer[12].
Radiation therapy uses high-energy X-rays to kill cancer cells. The most common way to have radiation therapy for metastatic breast cancer is to areas of the bone where the breast cancer has spread. Radiation therapy may also be given to the brain if cancer has spread there[13].
Drugs called bisphosphonates and denosumab help prevent or slow down bone thinning and can strengthen the bones to reduce the risk of fractures. These may be offered if breast cancer has spread to the bones[12][13].
Local treatments such as surgery may sometimes be recommended to remove metastatic lesions or to relieve symptoms[8][10]. Clinical trials testing new treatments are also an option for many people with metastatic breast cancer[8].
It is important to have open, clear communication with your doctor about your treatment plan. Make sure your doctor understands your priorities and preferences regarding treatment, whether it is quality of life, pain control, or being as aggressive as possible[8]. Remember that you can change your mind about your treatment choices at any time[8].
Living with Metastatic Breast Cancer
Being diagnosed with metastatic breast cancer can be overwhelming. You may feel angry, scared, stressed, or all these feelings[3]. There is no right or wrong way to come to terms with the diagnosis[3]. It takes time to adjust, and managing physical, emotional, and practical challenges is part of living with the disease[15].
Many people find it helpful to learn more about the diagnosis and different treatment options. Taking time to get a second opinion can also offer more peace of mind. For some people, gathering information provides a feeling of control, which can help manage fears[15].
Your mental health is just as important as your physical health when living with metastatic breast cancer. Support is available through mental and emotional health professionals at many cancer centers[15]. It can also help to talk with other people in the same situation through support groups, either in person or online[15][16].
Some people find that staying in the present moment helps them deal with fear and stress. Activities such as spending time with loved ones, making art, journaling, meditating, listening to music, or playing with a pet can help you stay present[15].
Taking care of yourself physically and emotionally can help preserve your sense of control and well-being[17]. Focusing on mindful breathing, maintaining a positive mindset through practices like meditation, prioritizing good nutrition, and making time for exercise can all contribute to improved quality of life[18].
It is normal to worry, but finding ways to cope with fear and grief involves gradually accepting the things you cannot change and finding a way to live with the situation[19]. Remember, it is okay to ask for help—and to be specific about your needs. Most likely, your family and friends want to help but are not sure what you need or want[15].
Many people with metastatic breast cancer live active, fulfilling lives for many years. With well-planned and individualized treatment and support, it is often possible to live with the disease and have a good quality of life[4][7].
