Metastasis refers to the migration of cancer cells from one location to another. In bone metastasis (also called secondary bone cancer), cancer has spread from another area of the body into the bones. Although any cancer can undergo metastasis to the bone, the ones most likely to spread are breast, prostate, kidney, lung and thyroid cancers.
Signs and Symptoms of Bone Metastasis
Bone metastases (also called bone mets) can either make the bone weak, leading to broken bones and large amounts of calcium being released into the blood, or make the bones harder, a condition called sclerosis. Both types of bone mets can be quite painful.
In addition to bone pain, the other possible signs and symptoms of bone metastasis include:
- Fractures, due to weak bones.
- High blood calcium. As bones break down, they release calcium into the bloodstream. High blood calcium can lead to loss of appetite, nausea, intense thirst, confusion and tiredness. Left untreated, high blood calcium can lead to coma.
- Pressure on the spinal cord, especially if the cancer is in the backbones. This pressure can damage the spinal cord, leading to numbness or even paralysis in the arms and legs. The first symptom of spinal cord pressure may be difficulty with urination, because nerves from the spinal cord control the bladder.
To diagnose bone metastases, a healthcare provider may use any of a number of imaging tests, including X-rays, bone scans, CT scans, MRIs or PET scans. Blood tests can detect tumor markers or high calcium levels. If the results of imaging and blood tests aren’t clear, the next step is a biopsy to test for secondary bone cancer.
Treatment of Bone Metastasis
According to the American Cancer Society, most healthcare providers treat bone mets by treating the cancer that caused them (2010). Treatment will depend on:
- Previous treatments for cancer
- The location of the bone metastases
- The type of cancer that caused the bone metastases
- Whether any bones are weak or broken
- Your overall state of health.
Chemotherapy, radiation, drugs and surgery are all potential treatments for metastasis to the bone. Although treatment often helps shrink bone metastases and relieve symptoms, bone mets usually aren’t curable. For this reason, follow-up exams are important to monitor the condition. Everyone responds differently to treatment, so work with your doctor to choose the best for your situation.
American Cancer Society. (2010). Bone metastasis. Retrieved October 4, 2010, from http://www.cancer.org/Cancer/BoneMetastasis/DetailedGuide/index.htm.
University of Michigan Comprehensive Cancer Center. (2010). Bone metastasis. Retrieved October 4, 2010, from http://www.cancer.med.umich.edu/cancertreat/tissue_bone/bone_metastasis.shtml.