The bones are the most common place where metastatic breast cancer cells tend to go. For more than half of women who develop stage IV breast cancer, the bones are the first site of metastasis. Although breast cancer can spread to any bone, the most common sites are the ribs, spine, pelvis, and long bones in the arms and legs.
A sudden, noticeable new pain is the most common symptom of cancer that has spread to the bone. It may come and go at first, but over time it can become constant. It can be hard to tell the difference between bone metastasis pain and pain due to arthritis or an exercise strain. If the pain feels just as bad or even worse when you rest or lie down, that can be a sign of a problem. Don’t wait to get it checked out; if it is bone metastasis, prompt treatment can prevent a fracture down the road. If you develop a skeletal-related event or SRE as a complication of bone metastasis, symptoms can include:
- Sudden severe pain and the inability to move, which can be a sign of fracture.
- Pain in the back or neck; numbness or weakness in an area of the body; or difficulty passing urine or having bowel movements. All can indicate a spinal cord compression, in which a fractured vertebra presses on the nerves in the spinal cord that control various bodily functions.
- Fatigue, weakness, nausea, loss of appetite, and/or dehydration, which all can indicate very high levels of calcium in the blood due to bone breakdown.
To diagnose bone metastasis, your doctor usually will order one or more imaging tests. Examples include:
- bone scan
- CT scan
- PET scan
You can read more about each of these tests in our Screening and Testing section.
Your doctor also might order a blood test to check for high levels of calcium or alkaline phosphatase (ALP), another substance that can be elevated due to bone metastasis.
In some cases, a biopsy is needed to confirm the diagnosis. With the aid of CT scans, your doctor can guide a small needle into the suspicious area and remove a sample of tissue to be examined in the lab. If the metastatic breast cancer started as an earlier-stage breast cancer, you can ask whether the cancer cells should be tested for characteristics such as hormone receptors and HER2 receptors in case they are different from the primary breast cancer.
The most common treatments for metastatic breast cancer in any location (bone, brain, lung, or liver) are systemic medications, which treat cancer throughout the entire body. Systemic medications include chemotherapy, hormonal therapy, targeted therapies, and bone-strengthening medication. Often, bone metastases can be stabilized and managed for long periods of time.
Local treatments — therapies directed specifically to the new locations of the breast cancer — aren’t usually the first choice for metastases. Still, local treatments are recommended under certain circumstances. Local treatments include surgery and radiation therapy.
You can read about systemic and local treatments for metastasis in the Recurrent and Metastatic Breast Cancer Treatment Choices section.