What Happens When Prostate Cancer Spreads to Bone?

When prostate cancer spreads to the bones, this is called “bone metastasis.” At this stage, complications such as bone pain, bone fragility, spinal cord injury, and resulting leg weakness or numbness can occur. Bone metastasis is a sign of advanced disease; if you experience these symptoms, you should notify your doctor immediately.

Prostate cancer has a strong tendency to spread (metastasize) to bone. Between 60% and 80% of people with prostate cancer eventually develop bone metastases. There are 2 main reasons for this:

1. A favorable bone environment for the growth of prostate cancer cells

2. Molecular changes on the surface of cancer cells and greater adhesion to bone

After prostate cancer metastasizes to bone, 2 major events occur: “destruction of bone tissue” and “formation of bone-forming lesions (osteoblastic lesions).” The second does not occur in most cancers. These changes can lead to problems such as bone pain and fragility.

The bones of the spine, pelvis, and ribs are more likely than other bones to be affected by prostate cancer metastases. This is because active red bone marrow and high blood flow create a suitable environment for prostate cancer cells to spread. If bone lesions develop in the spine, the spinal cord is at risk of compression and injury.

At this stage of cancer, radiation therapy and pain-relief medications help reduce symptoms. In some specific cases, radioactive drug injections or a small procedure on the vertebrae may be performed to reduce pressure on the spinal cord. Treatments such as chemotherapy and hormone therapy are also used to target tumors.

Note: Cancer cells in bone have a protective covering made of connective tissue, which can make them more resistant to treatment. In addition, metastasis is a sign that the cancer has progressed and spread. At this stage, given the resistance of cancer cells in bone, we recommend seeing a doctor as soon as symptoms appear.