Metastatic breast cancer is cancer that has spread, or metastasized, beyond the breast. Sometimes cancer cells will spread to local or regional lymph nodes. When breast cancer cells spread, or metastasize, to distant areas like the bone, liver, or lungs, it’s considered to be stage 4 breast cancer. This type of cancer is referred to as “metastatic.”

In some cases, breast cancer is metastatic at the time of diagnosis. In most cases, metastatic breast cancer develops after initial treatment of an earlier stage cancer. Despite your doctor’s best efforts, cancer cells can survive treatments. These cells can spread to your lymph nodes and then travel through your body and seed and grow somewhere else. That’s why metastatic breast cancer may show up months, years, or even decades after breast cancer is found, diagnosed, and successfully treated.

Distant Metastases Sites and Frequency

The most common first sites of distant metastasis are the:

  • bones
  • lungs
  • liver
  • brain

What Are the Symptoms of Metastatic Breast Cancer?

Symptoms can be hard to detect. Unfortunately, like earlier stages of breast cancer, metastatic breast cancer may not cause any symptoms until it has progressed significantly.

Because metastatic breast cancer affects other parts of your body, you may begin experiencing symptoms in the tissues or organs affected by the cancer. The symptoms you may experience depend on where the cancer metastasizes to in your body.

  • Metastatic breast cancer in the bone may cause bone pain. Your bones may also fracture more easily.
  • Metastatic breast cancer in the lungs may make breathing difficult and cause shortness of breath or difficult breathing.
  • Metastatic breast cancer in the liver may cause pain, nausea, weight loss, loss of appetite, and excessive fluid buildup on your abdomen. This buildup may cause swelling and bloating that can be uncomfortable and even painful.
  • Metastatic breast cancer in the brain may cause headaches, dizziness, seizures, difficulty with balancing, and blurry vision.

What Are the Risk Factors for Metastatic Breast Cancer?

Women in the United States aren’t commonly first diagnosed with metastatic breast cancer. This is partly because healthcare guidelines suggest starting regular mammograms earlier in life. Approximately 6 percent of breast cancer diagnoses are advanced metastatic breast cancer in the United States. This number is higher outside the United States where access to breast cancer screening mammograms isn’t as widespread.

Most metastatic breast cancer diagnoses come in women who have previously been diagnosed with and treated for a less advanced stage of breast cancer. Unfortunately, national estimates of recurrence aren’t available. Cancer research centers and registries don’t keep data on cancer recurrence and metastases. Estimates suggest that about 30 percent of women who have an earlier breast cancer diagnosis will eventually develop an advanced, recurrent, or metastatic cancer.

How Many People Are Diagnosed Each Year in the United States?

It’s estimated that 155,000 people in the United States are diagnosed with metastatic breast cancer each year.

Additionally, this type of breast cancer accounts for about 40,000 deaths annually in the United States.

About 6 percent of breast cancer cases diagnosed in the United States each year are stage 4 breast cancer, which is metastatic.

Who Gets Metastatic Breast Cancer?

Sex

Men can get breast cancer, but breast cancer in men remains rare. About 1 percent of all breast cancer cases in the United States occur in men. That number continues to climb each year. The rate of deaths due to male breast cancer decreased 1.8 percent per year from 2000 to 2012.

Men are more likely to be diagnosed with advanced stage breast cancer. That reflects the lack of awareness for breast cancer in men. The late diagnosis may also be the result of delayed detections and testing.

Ethnicity

The risk of being diagnosed at a later stage is higher for black women. Of all women diagnosed with breast cancer, 9 percent are black women with metastatic breast cancer. Approximately 5 percent are white women with metastatic breast cancer.

Age

Breast cancer rates tend to increase with age. In other words, the older you are, the higher your risk for breast cancer is likely to be.

Breast cancer diagnoses in white women are highest between the age of 60 and 84. Diagnoses are more common in black women before age 45. Those cases of breast cancer are also more likely to cause the woman’s death.

Costs

Healthcare costs associated with treating metastatic breast cancer are substantial.

According to one study, the average patient pays approximately $128,556 during their treatment period. Here’s how that payment is divided:

  • Outpatient services account for 29 percent of total costs.
  • Medication other than chemotherapy accounts for 26 percent of total costs.
  • Chemotherapy accounts for 25 percent of total costs.
  • Inpatient care accounts for 20 percent of total costs.

Survival Rates

Metastatic breast cancer isn’t considered to be curable, but many women will live for months to many years with minimal symptoms if they have appropriate treatment. The five-year survival rate for women diagnosed with metastatic breast cancer is 22 percent. Individual survival rates will vary depending on:

  • the site of metastasis
  • hormone receptor status
  • amount of time since initial treatment
  • prior therapies
  • human epidermal growth factor receptor 2, or HER2, status
  • overall health status
  • performance status

You can improve your quality of life by taking a few steps:

Increase Your Odds of Early Diagnosis

The sooner you find any cancer, even an advanced stage cancer like metastatic breast cancer, the sooner you can begin treatments. Earlier treatment may positively affect your quality of life and help delay or avoid painful or unpleasant symptoms. Part of early diagnosis includes keeping your regular checkups and making sure to report any unusual signs, symptoms, or changes to your doctor.

Follow Your Treatment Plan

If you’re indeed diagnosed again, you can increase your odds of minimizing symptoms and improving your quality of life by sticking to the treatment plan recommended by your doctor and following their recommendations. Treatment goals for metastatic breast cancer usually aren’t aimed at curing the cancer. Treatment can stabilize your cancer, reduce or prevent painful or unpleasant symptoms, and prolong your life. Many women with metastatic breast cancer will live for many years with minimal symptoms.