What is bone metastasis?
When breast cancer cells spread through the lymphatic system or blood vessels, they often take up residence in the bones, resulting in bone tumors, frequently called mets. By some estimates, nearly 70% of people living with metastatic breast cancer (mbc) have metastases to their bones.
The bone is a dynamic organ, constantly breaking down, building up and remodeling itself. This healthy cycle of growth is interrupted when cancer cells invade. With time, cancer cells damage the delicate balance between osteoclasts, which are bone cells that break down the bone, and osteoblasts, which are bone cells that build up the bone. While diagnostic scans may describe bone mets as either osteolytic (dissolving bone minerals) or osteoblastic (causing bone mass to be more dense), in most cases bone mets are both. In any event, tumors cause disruption in the healthy regeneration of bone, leaving the bone compromised and vulnerable.
For some, bone mets are symptomless, but for others, pain is present. Bone met pain has been described in various ways. For some, bone pain is a dull ache that is ever present; for others, it is sharp and intermittent. For yet others, the pain manifests itself like the sensation of a bruise.
How are they diagnosed?
Bone mets can be diagnosed using a variety of diagnostic tools. Patient reports of pain symptoms are a frequent early indicator. Blood work (including tumor markers tests) is a valuable tool in diagnosing bone mets. Exploratory tests such as x-rays, bone scans, cat scans, MRI scans and PET scans are used to confirm the presence of mets. While bone mets are most commonly found in the spine, ribs, pelvis, long bones of the arms or legs and the skull, it is possible to find bone mets in unexpected places such as the lower legs and wrists.
Bone mets are potentially quite damaging. Pain can be debilitating and necessitate treatment to help the patient be more comfortable. Severe skeletal related events, such as fractures and spinal cord compression, are less common, yet the possibility is of concern to both patients and doctors.
How are they treated?
Treatment for bone mets is multi-faceted and often involves pain medication, bisphosphonate treatments, radiation, systemic chemotherapy and, occasionally, surgery. Treatment varies per individual, based on need for symptom alleviation, extent of bone mets, the presence or absence of soft-tissue involvement as well as particular characteristics of the tumor (hormone receptor status, her2neu status). Because bone mets can be painful and even disabling, pain management is critical to maintaining well-being. It is important to report discomfort to treatment providers. In treating bone mets, the goals include restoring comfort and mobility, preventing new tumors from developing and maintaining stability. Even though bones mets may cause considerable pain and cannot be cured, effective treatment allows people to live well with bone mets.
This is a very complete and easy to read discussion of:
* Bone metastases in Breast Cancer * How mets grow in bone * Signs and Symptoms * Diagnosis * Testing (xray, bone scans, MRI, PET, CT) * Treatment * Bisphosphonates (Zometa, Xgeva, Aredia) * Managing Pain * Use of Radiation * Additional Resources
Dr. William Gradishar of Northwestern University speaks about Bone Mets at the 2012 MBCN National Conference: click HERE to view.