Understanding a Diagnosis of Metastatic Breast Cancer

An explanation of metastatic breast cancer, with questions and topics to discuss with a healthcare provider.

It is estimated that over 150,000 women in the United States are living with metastatic breast cancer, cancer that began in the breasts, but has spread to other parts of the body. Men can also have metastatic breast cancer, though all types of breast cancer are much less common in men. Metastatic breast cancer is sometimes abbreviated as MBC.

Metastasis is the spread of cancer throughout the body. This occurs when cancer cells break off from the original tumor and make their way into the blood or the lymphatic system, a network of tissues and organs that produce, store and carry white blood cells throughout the body. From there, these cancer cells can travel to other areas of the body where they grow and multiply. The most common areas of the body that MBC spreads to are the bones, lungs, liver and brain, though breast cancer cells can spread to any part of the body.

The majority of women diagnosed with MBC have previously been diagnosed and treated for an earlier stage of breast cancer. MBC occurs when breast cancer returns. However, a percentage of patients are diagnosed with MBC during their initial diagnosis.

What does a diagnosis mean?

Each case of metastatic breast cancer is unique and will take into account a number of factors. Some of the factors regarding MBC that should be discussed with your healthcare provider include:

  • What type of breast cancer is it?
  • What are the sizes of the tumors?
  • Has the cancer spread beyond the lymph nodes?
  • What parts of the body has cancer spread to?
  • What grade are the tumors? Grading is how abnormal the cancer cells look when examined with a microscope, given on a scale of 1 to 4, with 4 being the most abnormal and typically the most aggressive.
  • Are the cancer cells ER/PR (estrogen-receptor/progesterone-receptor) positive? ER/PR-positive means that the breast cancer cells can fuel their growth using the hormone estrogen.
  • Are the cancer cells HER2-positive? HER2 (human epidermal growth factor receptor 2) is a protein that promotes the growth of breast cancer cells.
  • What is my prognosis?
  • What treatment options are available?

Getting answers to these questions may require additional diagnostic tests. All of these factors and more are taken into account when deciding on a treatment plan. Because every case of metastatic breast cancer is unique, treatment is tailored to each patient.

Metastatic breast cancer cannot be cured. Treatment focuses on halting the progress of the cancer, minimizing symptoms, maintaining quality of life and prolonging life. There are many new treatments available that give patients a much better prognosis than patients who were diagnosed in previous years and decades. Published data shows that survival rates for patients with MBC are improving.

A diagnosis of MBC is a difficult diagnosis to receive, and a difficult topic to discuss. It can help to have a loved one or a close friend with you at an appointment to take notes and ask questions.

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