Makindo Medical Notes

Related Subjects: |Hypercalcaemia |Neutropenic Sepsis |Pulmonary Embolism |Superior vena caval obstruction syndrome |Cerebral Metastases |Metastatic bone disease |Oncological emergencies

Metastatic bone disease has a major impact on both the morbidity and mortality of patients

About

• Bone is the third most common site of metastasis for cancers
• It is common in people at advanced stages of these cancers
• Improve management of bone metastases secondary to breast and prostate cancer

Causes

• Lung cancer
• Breast cancer
• Prostate cancer
• Thyroid carcinoma
• Renal cell carcinoma
• Lymphoma
• Bladder carcinoma
• Myeloma

Types

• Osteolytic (e.g. Myeloma)
  • Calcium more likely raised. ALP normal unless fracture.
  • Lytic lesions are best detected with plain radiography.
  • Breast, lung, renal cell, myeloma and melanoma
  • Progression of osteolytic metastases is much faster
• Osteoblastic "Sclerotic" with bone growth (e.g. Prostate)
  • Calcium may be raised. Raised ALP.
  • Blastic lesions are prominent on radionuclide bone scans
  • Prostate cancer, and a subset of breast and lung cancers
• Most are mixed. bone-resorbing (osteoclasts) and bone-forming (osteoblasts) cells

Clinical

• Bone pain which may be worse at night
• Pathological fracture and deformity

Differentials

• Osteoarthritis, Degenerative disease
• Paget's disease, osteoporosis, or disc disease

Investigations

• U&E: raised Calcium, ALP high
• Where bone metastases are suspected, individuals should be assessed with a plain X-ray followed by radiological review and, if indicated, an orthopaedic opinion.
• Technetium diphosphonate bone scans are useful to delineate the extent of bony metastases and in following response to therapy. It can miss purely lytic lesions.
• Skeletal radiography supplemented with computed tomography and magnetic resonance imaging
• Skeletal survey is preferable for multiple myeloma

Complications

• Pain, impaired mobility, pathological fracture
• Spinal cord compression, cranial nerve palsies
• Nerve root lesions, hypercalcaemia, and suppression of bone marrow function.

Prevention

• In breast cancer, prostate cancer, and multiple myeloma patients, bisphosphonate therapy increases the time to a first skeletal event.
• Bisphosphonate therapy also appears to prolong survival in patients with metastatic breast cancer.

Management: depends on the underlying malignancy.

• Analgesia, bed rest and Imaging and Orthopaedic surgery can help treat/prevent pathological fractures and spinal decompression and stabilization to relieve spinal cord compression or instability
• Antitumour treatments such as external-beam radiotherapy, endocrine therapy, cytotoxic chemotherapy, targeted biological agents, and radioisotope therapy
• Antiresorptive bisphosphonates have revolutionized treatment and outcomes for patients with bone metastases, but pain and other skeletal complications still occur
• Bisphosphonates may reduce hypercalcemia, relieve pain, and limit bone resorption. Consider 4 mg zoledronic acid IV
• Denosumab is a new bone-modifying drug that has shown much promise in this setting. It is a fully-human monoclonal antibody to RANKL.
• Physical activity is promoted though those with metastatic bone lesions are at an increased risk of fracture and this needs to be taken into account when recommending exercise

References