When breast cancer spreads to other areas, it’s called metastatic, or stage 4, breast cancer. Breast cancer can spread to your bones, lungs, liver, and brain, among other parts of your body.

According to the National Cancer Institute, the most common metastasis locations for breast cancer are the:

  • bones
  • lungs
  • liver
  • brain

In a 2020 study of 414,528 people with breast cancer, 5,185 people (1.25%) developed metastatic breast cancer during the study period. The researchers found that in the people with metastatic breast cancer, the most common sites of metastasis were:

  • bone (in 54.06% of those with metastatic cancer)
  • lung (in 14.18%)
  • liver (in 10.5%)
  • brain (in 1.6%)

Additionally, 19.67% of people had metastasis in multiple organs.

Keep reading to learn more about these metastatic sites, the symptoms of metastasis, and how to lower your risk.

Bones are often the first site that breast cancer spreads to. It can spread to any bone, although the most common ones are the:

  • spine
  • pelvis
  • thigh

Metastasis to your bones may cause:

At first, it can be hard to tell the difference between a bone metastasis and the effects of a much more common condition such as arthritis or a strain. However, pain from bone metastasis doesn’t go away with rest.

If you’re experiencing frequent bone pain, talk with your doctor.

It’s possible to have a lung metastasis and not know it, because you may not experience any symptoms. In fact, your doctor may first find a lung metastasis during a follow-up scan after your initial treatment.

Metastasis to your lungs may cause symptoms such as:

It’s easy to mistake these symptoms for those of a preexisting lung condition or a respiratory infection such as the common cold or the flu. However, symptoms of lung metastasis will continue long after a respiratory infection should have cleared.

Breast cancer that has spread to your liver may not cause symptoms at first.

Because of this, it may first be detected when routine blood tests show elevated liver enzymes, which can be a sign of liver damage.

Metastasis to your liver may cause:

According to a 2023 research review, the spread of breast cancer to the brain is more common with aggressive types of breast cancer such as triple-negative and HER2-positive breast cancer.

Metastasis to your brain may cause:

Breast cancer can also spread to other areas of your body, although this is much less common. For example, it may spread to the:

  • female reproductive tract, including your ovaries, cervix, and endometrium
  • digestive tract, such as your esophagus, stomach, and colon
  • pancreas
  • kidneys
  • thyroid
  • eye

Healthcare professionals use several tests to confirm a diagnosis of metastatic breast cancer. These include:

The tests that doctors use as part of the diagnostic process can vary depending on where the cancer has spread to.

For example, imaging such as a bone scan would be used to check for a bone metastasis, while a head MRI would be used to check for a brain metastasis.

Additional tests may also be used, depending on the site. For example, a healthcare professional may perform a bronchoscopy to check for signs of cancer in your airways if they suspect a lung metastasis.

There is no way to guarantee that your cancer will not recur or spread after treatment, but there are steps you can take that may reduce your risk.

Managing your weight

A 2022 study found that obesity was associated with an increased risk of breast cancer recurrence after chemotherapy. Factors such as the increase in inflammation associated with obesity may play a role.

If you have obesity or are overweight, you can talk with your doctor about healthy ways to manage your weight.

Staying active

Keeping active is great for your overall health.

It may also reduce your risk of breast cancer recurrence and metastasis, as physical activity can have a beneficial effect on your immune system.

Eating a balanced diet

A 2022 research review suggests that excess intake of saturated fats and carbs may promote breast cancer metastasis to the liver.

To eat a balanced diet, try to do the following:

  • Eat more fresh fruits and vegetables, whole grains, legumes, poultry, and fish.
  • Reduce your consumption of red and processed meats if you typically eat a lot of them.
  • Avoid ultra-processed foods and foods with a lot of added sugars.

Limiting alcohol intake

Aim to drink alcohol in moderation or not at all. Moderate drinking is one drink per day for women and two drinks per day for men.

Alcohol consumption is a risk factor for developing breast cancer, but there are few studies on alcohol’s impact on cancer metastasis and recurrence. Thus, more research is needed.

Metastatic breast cancer happens when the cancer spreads to more distant areas of your body. The most common locations that breast cancer may spread to are your bones, lungs, liver, and brain, although metastasis can occur in other areas of your body.

The symptoms of metastatic breast cancer depend on which part of your body is affected. A doctor will use blood tests, imaging tests, and tissue biopsies to help them make a diagnosis.

You may be able to reduce your risk of breast cancer metastasis by making lifestyle changes such as managing your weight, staying active, eating a balanced diet, and limiting or eliminating alcohol consumption.