Metastatic breast cancer (MBC) is breast cancer that spreads from the breast to other parts of the body, such as the bones, liver, lungs, or brain. Recognizing the symptoms of metastatic breast cancer is important for prompt diagnosis and intervention, which can help manage symptoms and improve quality of life. This article describes common signs and symptoms of MBC and available treatment options.

Common Signs and Symptoms of Metastatic Breast Cancer

The symptoms of metastatic breast cancer can vary depending on the organ or tissue affected. Here are some key signs and symptoms associated with MBC:

Bone pain

Persistent pain in the bones, especially in the back, hips, or legs, may indicate that the cancer has spread to the bones.

Shortness of breath

Cancer that has spread to the lungs can cause difficulty breathing or a persistent cough.

Abdominal pain or swelling

If the cancer has spread to the liver, abdominal pain or swelling, nausea, and loss of appetite may occur.

Headache or nervous system changes

If the cancer affects the brain, symptoms may include headaches, vision problems, memory problems, or seizures.

Fatigue

Fatigue is common in metastatic cancer and is often a result of the effects of the cancer on the body and ongoing treatment.

Swelling of the feet or legs (peripheral edema)

Swelling, especially in the feet or legs, can be caused by the cancer itself or by treatments such as chemotherapy, hormone therapy, or immunotherapy. Swelling caused by cancer treatment is usually mild and often goes away after treatment (source: National Cancer Institute).

If these symptoms persist, it may be helpful to see a doctor, as early intervention can help treat metastatic breast cancer more effectively.

Metastatic breast cancer may be more common than you think

Metastatic breast cancer affects a large portion of people diagnosed with breast cancer. Between 2001 and 2021, there were approximately 4,652,885 new cases of breast cancer in women in the United States, of which 260,379 (5.6%) had metastases at the time of diagnosis. The incidence of metastatic breast cancer increased from 5.8 cases per 100,000 women in 2001 to 7.9 cases per 100,000 women in 2021 (source: CDC).

In the United States, about 1 in 8 women are diagnosed with breast cancer, and about 1 in 3 of these cases eventually develop metastases. There are also disparities in outcomes, with African American women 40% more likely to die from breast cancer than white women (source: Metavivor).

Available treatment options for metastatic breast cancer

Although metastatic breast cancer is currently incurable, there are a variety of treatments that can relieve symptoms and slow the progression of the disease. Here are some commonly prescribed drugs for MBC:

Ibrance (palbociclib)

Ibrance is a type of targeted therapy called a CDK4/6 inhibitor that works by blocking an enzyme involved in cell division, thereby slowing the growth of cancer cells. It is often used with hormone therapy for women with hormone receptor-positive (HR+), HER2-negative metastatic breast cancer.

Pros: Targets HR+ and HER2-negative cancers specifically, potentially improving progression-free survival.

Cons: Side effects may include fatigue and a decrease in white blood cells, which can increase the risk of infection.

Verzenio (Abemaciclib)

Verzenio is another CDK4/6 inhibitor that works similarly to Ibrance, slowing the growth of cancer cells by blocking proteins involved in cell division. It can be used alone or with hormone therapy for HR+ and HER2-negative MBC.

Pros: Effective when used in combination with hormone therapy, especially for HR+ and HER2-negative MBC, and may slow disease progression.

Cons: Side effects may include diarrhea, fatigue, and low white blood cell counts.

Kisqali (ribociclib)

Kisqali is also a CDK4/6 inhibitor that is often used with hormone therapy for HR+ and HER2-negative MBC. It blocks proteins that promote cancer cell growth.

Benefits: Can extend progression-free survival and improve quality of life in HR+ and HER2-negative patients.

Cons: Side effects may include nausea, elevated liver enzymes, and fatigue, requiring regular monitoring as needed.

Nerlynx (neratinib)

Nerlynx is a tyrosine kinase inhibitor used to treat HER2-positive breast cancer. It targets the HER2 protein to inhibit the growth of cancer cells, so it is suitable for HER2-positive metastatic breast cancer.

Pros: Offers a targeted approach for HER2-positive MBC that, when combined with other treatments, may improve outcomes.

Cons: Possible side effects include diarrhea and fatigue; supportive care may be required.

Conclusion

Metastatic breast cancer presents unique challenges, and although it is a chronic disease, a variety of treatments can help relieve symptoms and slow disease progression. Early recognition of symptoms and consultation with a healthcare professional can improve quality of life and the opportunity to customize treatment. By understanding available treatment options, people affected by MBC can take an active role in managing their disease and maintaining their health.