What is metastatic breast cancer?

Metastatic breast cancer is cancer that originated in the breasts and has spread to other parts of the body. It may be apparent at the time of initial breast cancer diagnosis and treatment or occur months or years later as recurrent breast cancer.

Metastatic breast cancer is also known as stage IV breast cancer. In addition, metastatic breast cancer may be called advanced cancer. Advanced cancer generally refers to cancer that can't be cured, but some health professionals may use the term differently.

In metastasis, cancer cells break away from the area where they first formed and travel through the blood or lymph system to form new tumors. Metastatic cancer that spreads from its original location is known by the name of the primary cancer. For example, cancer that has spread from the breasts to the lungs is called metastatic breast cancer rather than lung cancer.

When examined under a microscope, metastatic breast cancer cells from the secondary location share similarities with breast cancer cells rather than cancer cells from the new location. That, along with other tests, is how doctors can usually tell that it's metastatic cancer that has spread from another part of the body rather than a new primary cancer. Second primary cancers do occur but are rare.

Metastatic breast cancer can occur in any part of the body but most commonly affects the bones, brain, liver or lungs.

Symptoms of metastatic breast cancer

Symptoms of metastatic breast cancer vary depending on where the cancer has spread, such as:

Bones

  • Severe, worsening pain
  • Swelling
  • Bones that are prone to breakage and fracture

Brain

  • Recurrent, progressively worsening headache
  • Vision problems
  • Seizures
  • Vomiting or nausea

Liver

  • Yellow appearance of the skin (jaundice)
  • Rash or itchy skin
  • Abdominal pain, loss of appetite

Lungs

  • Persistent cough
  • Difficulty breathing
  • Chest pain
March 22, 2017 See more In-depth