Metastatic breast cancer is the most advanced stage of breast cancer (also known as stage IV), which means the cancer has spread beyond the breast to other parts of the body.
Some women have metastatic breast cancer when they are first diagnosed (called de novo metastatic breast cancer), but this is uncommon. “About 10% of breast cancers present initially with metastatic disease, but the majority of patients present with early stage breast cancer,” says Amy Tiersten, MD, a hematologist and oncologist at the Mount Sinai Hospital in New York City.
While many cases of early stage cancer can be cured, in some instances the cancer comes back years later as metastatic breast cancer, and is typically diagnosed during routine follow-up appointments. “Those visits are about screening patients for any symptoms that could be suggestive of metastatic disease,” says Dr. Tiersten. “[Looking for] metastatic breast cancer is very symptom driven.”
Symptoms of Metastatic Breast Cancer
The most common sites for metastatic breast cancer to spread are:
Rarely, metastatic breast cancer will spread to the ovaries. The symptoms that present with metastatic breast cancer usually depend on where the cancer has spread.
“[During the follow-up appointment] we do a very careful history about any new symptoms they might be having as well as a physical exam,” says Dr. Tiersten. “So, it could be something we find on physical exam. For example, if someone has lung metastases with fluid around the lung you can hear that with a stethoscope.”
Bone metastasis symptoms
The bones are the most common place where metastatic breast cancer cells tend to spread. For more than half of women who develop stage IV breast cancer, the bones are the first site of metastasis. Although breast cancer can spread to any bone, the most common sites are the ribs, spine, pelvis, and long bones in the arms and legs. If metastatic breast cancer has spread to the bones, the patient might have:
“We all get aches and pains, but the key finding here is that there’s no explanation [and] no injury. There’s a new pain somewhere and it’s just not getting better or it’s getting worse. That would be something to call your oncologist about,” says Dr. Tiersten.
Lung metastasis symptoms
When breast cancer moves into the lungs, it often causes no symptoms. Instead, a tumor might be first discovered on an imaging study done as part of treatment follow-up, such as a chest CT (computed tomography) scan. If metastatic breast cancer has spread to the lungs, a patient might have these symptoms:
Liver metastasis symptoms
When breast cancer moves into the liver, it may not present symptoms either. It may first be picked up by liver function tests, which are blood tests that measure certain levels of enzymes and proteins in the blood. Abnormal levels can indicate liver disease or damage. If metastatic breast cancer has spread to the liver, a patient might have these symptoms:
Lymph node metastasis symptoms
If breast cancer has spread to the lymph nodes, it doesn’t automatically mean you have metastatic breast cancer. After or during early stage breast cancer treatment, your doctor may perform a physical exam to check for changes to the lymph nodes. Lymph nodes are small and hard to find, but when there’s an infection or cancer, they can grow larger. Your doctor will look for:
Even though a physical exam may be performed, a pathology exam is the best way to know your lymph node status. To conduct this, your doctor will remove one or more of the lymph nodes under the arm near the original cancer site to see if the cancer has spread. If cancer cells are found, that’s called lymph node involvement.
The more lymph nodes that contain cancer cells, the more serious the cancer might be. “Breast cancer can spread through the lymph nodes under the arm, and travel by lymphatic channels or blood vessels to other parts of the body,” says Dr. Tiersten.
Brain metastasis symptoms
About 10% to 15% of women with stage IV breast cancer develop brain metastases. In most cases, the breast cancer has already traveled to another part of the body, such as the bones, liver, or lung. However, for about 17% of women in this group, the brain is the only site of metastasis. If metastatic breast cancer has spread to the brain, a patient might have these symptoms:
The risk of cancer spreading to the brain is usually highest for women with more aggressive subtypes of breast cancer, such as HER2-positive or triple-negative breast cancer.
If you’ve had early-stage breast cancer, it’s important to be on the lookout for any of these new or unusual body changes, and talk to your oncologist if you’re concerned. But Dr. Tiersten doesn’t want her patients living in constant fear of metastatic breast cancer either.
“It’s really important to educate people on how well people can do. A lot of patients can do really well with metastatic disease and live many years with good quality and quantity of lives, we have great treatment for it,” says Dr. Tiersten. Patients are living sometimes without evidence of disease for many years more and more.”