5.7 Bone metastases Flashcards
What is neoangiogenesis?
When tumours recruit blood vessels through a combination of hypoxia and cytokine release
What is intravasation?
When tumour cells enter the blood stream either actively or passively
What is needed for tumour cells to extravasate?
Adhere to side of the vessel
Invade through the vessel wall
Establish new blood supply
What is the role of osteoclasts?
Resorb bone
What is the role of osteoblasts?
Form new bone
What is the role of cytokines in bone metastases?
Local release of cytokines by malignant cells drives activation of osteoclasts and suppression of osteoblasts allowing for destruction of adjoining bone
What peptide do malignant cells release which is thought to be involved in bone mets and what happens when there is too much?
Parathyroid hormone related peptide
When there is high levels there is bone demineralisation in the absence of local metastases
What causes hypercalcemia?
Bone mets causing localised destruction of bone and release of calcium, can be due to ectopic production of parathyroid hormone related peptide
What are the dangers of hypercalceamia?
Dehydration, renal failure, confusion, pain, renal calculi
potentially fatal
What is the treatment of hypercalcaemia?
IV fluids only is 3
What is the usual presetation of spinal cord compression?
Pain - radicular pain at the level of compression and weakness/sensory changes below the level
What is the treatment for spinal cord compression?
dexamethasone 8mg to reduce oedema and protect the cord
Radiotherapy
What is the typical presentation of bone mets
Typically sever pain which continually worsens and is often worse on mobilisation of the affected area
Will often not respond to simple analgesia
What are the typical areas of bone mets?
Spine and pelvis
What is teh imaging for bone mets?
Local imaging
CT if symptoms of cancer
Whole body scan for other sites of mets
MRI to examine spinal cord
