Overview
Bone metastasis refers to cancer cells that have migrated from a primary tumor and established growths within bone. The process of cancer spreading is known as metastasis, and the originating disease is usually a form of cancer. Bones are a frequent target because their marrow and microenvironment can support tumor cell survival and proliferation.
Common sources and types
Several solid tumors commonly seed the skeleton. Most frequently these include:
- Breast cancer
- Prostate cancer
- Lung cancer
- Kidney and thyroid cancers
Bone lesions are often described as osteolytic (bone-destroying), osteoblastic (bone-forming), or mixed, reflecting how tumours interact with osteoclasts and osteoblasts.
Signs, complications, and clinical importance
Symptoms may include persistent bone pain, fractures with minimal trauma, reduced mobility, and, in advanced cases, spinal cord compression. Tumor-induced bone breakdown can raise blood calcium levels (hypercalcemia), which is a potentially serious metabolic complication. These outcomes, sometimes grouped as skeletal‑related events, heavily influence quality of life and treatment choices.
Diagnosis and evaluation
Diagnosis combines clinical assessment with imaging and laboratory tests. X-rays, bone scans, CT, MRI and PET can detect lesions and assess extent. Blood tests may show elevated markers or calcium changes, and a biopsy of a bone lesion can confirm the diagnosis and identify the tumor type to guide systemic therapy.
Treatment and management
Management aims to control pain, prevent complications and treat the underlying cancer. Approaches include systemic therapies (hormonal treatment, chemotherapy, targeted agents), localized radiotherapy for pain and control, bone-modifying agents such as bisphosphonates or RANKL inhibitors, and surgery for stabilization of fractures or decompression. Palliative care and rehabilitation are important for maintaining function.
Distinctions and prognosis
Bone metastases are distinct from primary bone tumors (which originate in bone tissue). Prognosis varies widely depending on the primary cancer type, burden of disease, available systemic treatments, and patient factors. While bone metastases are often not curable, many patients achieve prolonged control and symptom relief with modern multidisciplinary care.