Overview

Metastatic breast cancer (also called stage IV breast cancer) refers to cancer that has spread from the breast to other parts of the body. Common sites of spread include bone, liver, lungs and brain. Metastatic disease is generally considered incurable with current standard therapies, but many treatments can slow progression, control symptoms and prolong survival while preserving quality of life.

Characteristics and diagnosis

Diagnosis usually combines imaging (such as CT, bone scan, MRI or PET) with tissue sampling when feasible to confirm that a distant lesion represents breast cancer rather than a new primary. Tumor biology—especially hormone receptor (estrogen and progesterone) status and human epidermal growth factor receptor 2 (HER2) expression—remains central to choosing therapy. Clinicians also assess performance status, extent and location of metastases, prior treatments and patient preferences.

Treatment approaches

The goals of treatment are to control disease, relieve symptoms and maintain quality of life. Approaches are individualized and often combined:

  • Systemic therapies: endocrine (hormonal) therapy for hormone receptor–positive cancers (for example, agents such as tamoxifen or aromatase inhibitors), and chemotherapy for more rapidly progressive or hormone-refractory disease.
  • Targeted therapies: agents directed at molecular features, such as HER2-targeted drugs for HER2-positive tumors, and other targeted agents matched to specific tumor alterations.
  • Biologic and antiangiogenic agents: some drugs that block blood vessel growth or specific signaling pathways have been investigated in combination with chemotherapy; their regulatory status and clinical use vary by country and over time. For example, bevacizumab has been studied with paclitaxel in metastatic breast cancer in some settings.
  • Local treatments: radiotherapy or surgery may be used to relieve symptoms from a dominant lesion (such as bone pain or spinal cord compression) or to control isolated sites of disease.
  • Supportive care for complications: bone-directed agents such as zoledronic acid (Zometa) or other bisphosphonates and denosumab are commonly used to reduce skeletal-related complications in patients with bone metastases.

Management goals and examples

Therapy is often sequential: a patient may receive endocrine therapy until disease progresses, then switch to targeted therapy or chemotherapy. Palliative radiotherapy can rapidly control pain or bleeding from local tumors. Multidisciplinary care—including oncology, palliative care, nursing and allied services—helps address symptoms, side effects and psychosocial needs.

History, regulatory notes and distinctions

Research in metastatic breast cancer has expanded from cytotoxic chemotherapy to targeted and biologic agents guided by tumor subtypes. Some drugs have been approved in particular combinations or regions while their indications have evolved with new evidence; regulatory decisions can vary internationally. It is important to distinguish metastatic disease from locally advanced breast cancer (extensive disease confined to the breast and regional nodes) and the emerging concept of oligometastatic disease, where a limited number of metastases may be treated more aggressively in selected patients.

Further information

For general background on the primary condition, see breast cancer. For details about systemic treatment options and supportive agents consult specialist sources and treating teams to understand the most up-to-date recommendations available in your region.