How Breast Cancer Metastasizes
When breast cancer metastasizes, the cancer cells enter the lymphatic channels or the bloodstream and spread to lymph nodes or other organs of the body.
Breast cancer cells can travel away from the breast and get into the blood stream fairly easily. Only a few can survive and grow in other organs. Typically, your body will reject or attack things it doesn’t recognize (like germs). But in the case of metastases, cancer cells seem familiar enough that different areas of the body allow them to grow.
The most common locations of breast cancer metastases are the liver, bones, lungs and brain.
If you had breast cancer before, the metastasis may be referred to as recurrent disease. In this case, some of the primary cancer cells survived the treatments you may have had after your early-stage diagnosis. Systemic therapies like hormonal therapy and chemotherapy aim to kill cancer cells in the breast as well as those that may have already started traveling to other parts of the body. In some cases, those cells escape the cancer treatment and begin to grow later.
Many researchers have studied the process of metastasis. To date, no one can predict how long cancer cells will be dormant before they begin to grow and can be detected.
Even though the cancer cells spread to a different area of the body, your doctors will still treat them as breast cancer. Being diagnosed with bone metastasis is not the same as being diagnosed with bone cancer. Under a microscope, the cancer cells in your bone still look the same as breast cancer cells. They will respond best to treatments for breast cancer.
If this is your first cancer diagnosis, it’s possible your doctors discovered you have breast cancer because you had symptoms in a different area of your body, like your bones. Your doctors were able to make the diagnosis because breast cancer cells remain breast cancer cells, no matter where they are.
Your doctors should run tests to make sure that the cancer cells from the metastatic site are the same as your primary diagnosis, if you had one. They will adjust your treatments if needed, for the best results possible.