Bone Pain Flashcards
1
Q
What are Skeletal related events?
A
- bone pain
- pathologic fractures
- hypercalcemia
- spinal cord compression
- most common metastatic breast and prostate cancers (70% with advanced disease)
2
Q
Features of bone pain
A
- intermittent, continuous, incident pain
- severe pain with coughing, turning in bed, gentle touching, movement
- well localized, aching or sharp
- provoked by pressure to area
3
Q
Mechanism of bone mets causing pain
A
- vascular occlusion
- compression of bone or peripheral nerve
- mechanical instability
- cancer induced osteoclast activity – influence resorption by osteoclasts
- bone has sensory and sympathetic fibres
- Stimulation of sensory afferent nerves in cortex, periosteum, soft tissue
- tumour cells (macrophages, neutrophils, T cells, lymphocytes) secrete prostaglandins and cytokines –> pain
- calcitonin gene related peptide (CGRP), glutamine, histamine, sub P secreted
4
Q
Pathophysiology of bone pain
A
- osteoblasts and marrow express RANKL normally
- RANKL binds to RANK receptor on pre osteoclasts and mature osteoclasts
- Bone resorption regulated by OPG (osteoprotegerin) produced by osteoblasts
- binds to RANKL and prevents interaction between RANKL and RANK
- cancer cells invade and cause excessive osteolysis via RANK expression or PTHr-P on OPG and RANKL production
5
Q
Spinal cord and bone pain
A
- expression of dynorphin
- proliferation of astrocytes in spinal dorsal horn
- spinal sensitization
- bone pain differs from inflammatory or neuropathic pain
- complex pathophysiology
6
Q
XRAYS for diagnosis of painful bony metastases
A
- 85% dense cortical bone, 15% porous trabecular bone (collagen, minerals)
- Red marrow in axial skeleton, fat marrow in appendicular skeleton
- XRAY :
- absent density or trabeculation - osteolytic lesions
- 30-75% of normal bone mineral content must be lost to show osteolytic lesions
- Increased density or sclerotic lesions, rims - osteoblastic lesions
- useful for assessing high risk of fracture, but can be late finding
- sensitivity 44-50%
- most useful for lytic disease (MM)
7
Q
Bone scans for bony metastatic disease
A
- sensitivity 62-100%
- specificity 78-100%
- also show uptake in OA, infection, trauma, Paget’s disease
- Typically shows osteoblastic activity
- False negative for lytic disease or rapidly progressive disease
8
Q
CT and MRI for bony metastatic disease
A
- CT sensitivity 71-100%, specificity 85-100%
- MRI sens 70-100%, specificity 73-100%
- MRI useful for soft tissue and spinal cord visualization
- PET scan - high sens and specificity
9
Q
Pharmacological approach to malignant bone pain : opioids
A
- Mild:
- NSAID or acetaminophen
- Moderate-severe:
- opioids ATC with breakthrough
- Incident pain (worse outcome, decreased QOL)
- Fentanyl SL 5-20% total daily dose, but variable ++, no correlation to daily dose
10
Q
NSAIDS
A
- inhibit cyclooxygenase (COX1)
- COX1 in platelets, GI tract, kidneys
- COX 2 kidneys and CNS, peripheral tissues
- NSAIDS have effect on spinal cord and brain
- Risk of toxicity:
- age
- previous PUD
- comorbid illness
- multiple NSAID use
- steroid + NSAID
- prescribe gastroprotectant (PPI, H2 blockers, misoprostol)
- Monitor renal function
- Hydration
11
Q
Steroids
A
- effective for bony pain, but little evidence
- SE:
- thrush
- osteporosis
- myopathy
- short term use (weeks) or short life expectancy
- peri-radiation therapy
12
Q
Bisphosphonates
A
- synthetic analogues of pyrophosphate
- bind to bone matrix, cause osteoclast apoptosis and reduce bone resportion
- reduced SRE in breast cancer and MM
- Systematic review bisphosphonates provide modest pain relief at 12 weeks, but insufficient evidence for immediate pain relief.
- Used early in MM and breast cancer
- Used if RT and analgesic ineffective
- evidence for lung, GI, prostate, breast, MM pain relief
- IV preferred to oral as better bioavailability, avoidance of GI distress and probably better analgesia
- Clodronate can be given SC
- Renal impairment –> hydration
- Osteonecrosis of the jaw : dental assessment and monitoring, avoid invasive dental procedures
13
Q
Calcitonin
A
- hormone that inhibits osteoclastic bone resorption
- pain managment from OP fractures, hypercalcemia
- systematic review: no evidence of effect in bony metastatic disease
14
Q
Non pharmacologic treatments
A
- non weight bearing
- heat
- ice
- gentle massage
- OT/PT assessment
- equipment
15
Q
Radiotherapy for bony metastatic disease
A
- Systematic review 40% of patient get at least 50% relief
- 30% get complete relief at 1 month
- Single fraction : higher rate of re-treatment, more pain flares, poss greater fracture risk
- less burdensome, less costly
- Multiple fraction
- preferred if prior RT
- treat or prevent path fractures
- spinal cord or cauda equina involvment
