There are a lot of things that help determine your prognosis, or outlook, after being diagnosed with breast cancer. Some factors that play a role include what type of breast cancer you have, how big your tumor is, which gene changes are found in your cancer cells, and how old you are when you are diagnosed. Whether or not your cancer is metastatic (has spread around the body) also plays an important role in your prognosis. While metastatic breast cancer can be more difficult to treat, new therapies can help many people live a long time after receiving this diagnosis.
Metastatic or stage IV breast cancer has spread from the breast to other parts of the body.
Breast cancer most often spreads to the bones, brain, liver, and lungs.
Medications that travel throughout your body are often most effective at treating breast cancer in various locations.
Treatments may help you continue to take part in your usual daily activities for many years after a diagnosis of metastatic breast cancer.
What is metastatic cancer?
Metastatic cancer occurs when cancer develops in one location — in this case, in the breast — and then travels to other parts of the body. Cancer cells in these other areas are then called “metastases.” Breast cancer cells are most likely to spread to the bones, brain, liver, and lungs.
Breast cancer can also spread to the lymph nodes — small, round glands that help fight infection, remove wastes from the body, and filter out old, damaged, or cancerous cells. There are many lymph nodes in the breast and armpit area that breast cancer can spread to. However, breast cancer that is found in the lymph nodes is not considered to be metastatic; instead, doctors refer to it as “locally advanced.” Cancer cells need to spread farther to be considered metastatic.
Spreading to the lymph nodes can be the first step before metastasizing around the body. Cancer cells can break off of the original tumor and travel to other locations through lymph vessels (tubes that connect all of the lymph nodes). They can also spread after entering the bloodstream.
Metastatic breast cancer is also described as stage IV breast cancer. This is the most advanced cancer stage.
How common is metastatic breast cancer?
Breast cancer is often found before it has begun to spread. About 6% of breast cancers are metastatic at the time of diagnosis.
Detecting metastatic breast cancer
An important part of diagnosing breast cancer is checking to see whether there are any cancer cells in the lymph nodes. This indicates whether cancer has begun to spread beyond the breast.
In some cases, doctors may remove large groups of lymph nodes to check for cancer, in a procedure known as axillary lymphadenectomy. More often, doctors will perform a sentinel lymph node biopsy. In this procedure, they will inject a dye or radioactive material into the breast to see which lymph node the fluid travels to first. This tells doctors which lymph node or group of nodes is the main drainage site for the breast. These nodes will be removed and checked for cancer. These procedures may occur during breast cancer surgery.
If cancer cells are detected in the lymph nodes, or if you have symptoms that may indicate that cancer has spread to other areas, doctors may check for metastases using tests like:
- A CT scan or PET scan to look for cancer cells in various locations throughout the body.
- A chest X-ray to look for abnormal masses in the lungs.
- A bone scan to detect cancer cells in the bones.
Your doctor can help you understand whether you are at risk for metastatic breast cancer or whether you need any of these tests.
Treating metastatic breast cancer
Metastatic breast cancer can’t be cured, but that doesn’t mean the situation is hopeless. Treatments may help you go into remission (have your cancer lessen or disappear) for many years.
Early-stage breast cancer is often first treated with surgery. However, doctors usually recommend other treatments for metastatic disease, because it may not be possible to surgically remove cancer in multiple areas of the body. Systemic treatments — drugs that travel around the body through the bloodstream — may work better because they can destroy cancer cells in any location. These treatments may include:
- Hormone therapy — This treatment can help treat cancer that is hormone receptor-positive (contains the proteins ER, PR, or both). These cancers use hormones as fuel, and hormone therapy helps prevent cancer cells from getting hormones, helping “starve” them.
- Targeted therapy — These drugs recognize and attack specific proteins found on cancer cells. It may be a good option for those with HER2-positive breast cancer (cancer that contains high levels of the HER2 protein) or for those with hormone receptor-positive cancers if hormone therapy doesn’t work.
- Chemotherapy — These drugs can kill any quickly-dividing cells throughout the body.
- Immunotherapy — This form of treatment can help the immune system become better at finding and killing cancer cells.
In some cases, surgery may be used to remove metastases that have spread to the brain or lungs. Surgery and radiation therapy may also help if breast tumors or metastases are causing symptoms like pain. Your oncologist may also be able to prescribe you other medications to help with specific symptoms.
Some people with metastatic breast cancer receive treatment through clinical trials. Participating in a study may give you access to new treatments that aren’t yet available through your doctor.
Survival rates for metastatic breast cancer
Those with metastatic breast cancer are more likely to have a worse prognosis. Overall, past data has shown that about three out of 10 people with the condition live for five years or more after being diagnosed. However, treatments are constantly improving, and people being diagnosed today with metastatic cancer may have a better outlook.
Having metastatic breast cancer will most likely mean that you won’t live as long. However, it also doesn’t necessarily mean that you will die soon. Some people can live a fairly normal life for many years after a diagnosis. You will likely have to undergo regular breast cancer treatments and may have to take cancer medication every day. Your cancer care team can help you find a treatment plan that helps you live with the best possible quality of life.