Bone metastasis dr g s patnaik

Overview
• Molecular mechanisms
• Origin & distribution
• Clinical features
• Medical management
• Surgical management
• Cases

Molecular mechanisms of metastasis
• Analysis of 735 autopsy records of breast
cancer patients
• Identified a non-random pattern of
metastases
• The Lancet 1889 : ‘seed and soil hypothesis’
Dr Stephen Paget
Surgeon & pathologist
1855-1926

Metastatic cells
• Small aggressive population
• Not all circulating cancer cells form a
metastasis
• Animal models show that 100s of cells detach
and circulate each day
• 0.1% are viable 24 hours later
• 0.01% form a metastasis

Origin & distribution
• Types of tumour spread to bone
o Breast
o Prostate
o Lung
o Kidney
o Thyroid
• Differential: myeloma and lymphoma
• Skeleton is ⅓ most favoured site for metastasis
of solid tumours (after liver and lung)

Frequency of skeletal metastases at
autopsy
Tumour Bone metastases (%)
Breast
Prostate
Thyroid
Kidney
Lung
Oesophagus
GI tract/colon
Rectum
Bladder
Uterine/cervix
Ovaries
Liver
Melanoma
50-85
60-85
28-60
33-60
32-64
6
3-10
8-60
42
50
9
16
7

Clinical features of bony metastases
• Bone pain
• Pathological fracture
• Nerve compression
• Hypercalcaemia

Bone pain
• Frequent in all lesion types
• Exact mechanisms unclear
• Remissions and exacerbations
– No obvious change in lesions

Pathological fractures
• Trivial injury
• Associated with lytic lesions
• Sites: Vertebral bodies & proximal long bones

Nerve compression
• Vertebral # and deformity
• Direct pressure on spinal cord by metastasis
• Osteoblastic lesion overgrowth
• Skull lesion- impingement on foramina

Hypercalcaemia
• Common: particularly osteolytic metastases
• Less common in prostate cancer
• 30% breast cancer patients at some point during
illness course (usually late on)
• Causes:
– Excessive bone resorption
– Impairment renal calcium excretion
• CHECK PTH before treatment if originating cause
unknown
• Treat with i.v. bisphosphonate

Surgical management
• Approx 1.5% of patients with bone metastases
require surgery (pre or post #)
• Stabilise long bones prior to #
• Spine
– Cord compression
– Instability
– Occasionally amenable to
vertebroplasty/kyphoplasty
• Radiofrequency ablation increasing in use
Urgent
decompression &
stabilisation

Relative Contraindications
• Moribund patient
• Infected wound in surgical region
• Acute DVT, especially if accompanying PE
• Extensive neurovascular encasement by soft
tissue tumour extension
• Severe malnutrition
• Short expected survival

Planning surgery
• CT useful for pre-op planning
• Goal is early return to reasonable function/weight bearing
• Reconstruction nail for femur (pertrochanteric and shaft)
• No indication for standard femoral nail
• Bipolar for neck/head metastases (ensure no significant acetabular
metastases)
• Retrograde nail only if adjacent previous THR
• Various i.m. nails for humerus
• Cement (with antibiotics and anticancer agents) to fill large defects
• Massive endoprostheses or arthroplasty
– Large diffuse areas of destruction (usually already fractured)
– Lesions affecting adjacent joints
• Minimal role for plates and screws

Final points
• Does IM nailing embolise metastases?
– No evidence in animal models
– No clear evidence that unreamed nailing is safer
• There is a significant risk of intra and
postoperative PE
– Surgical & anaesthetic team must be on the alert
– Pulse lavage in between reaming may reduce the
risk
– Venting reduces pressure (cadaver study)

Score 1 2 3
Pain Mild Moderate Functional
Site Upper limb Lower limb Per troch
Size ⅓ ⅓-⅔ >⅔
Type Blastic Mixed Lytic
Score=8
6 month # risk 15%
72 year old lady with known breast cancer

Score 1 2 3
Size ⅓ ⅓-⅔ >⅔
Score 10
6 month # risk 72%

Score 1 2 3
Size ⅓ ⅓-⅔ >⅔
Score=8
6 month # risk 15%

Score 1 2 3
Size ⅓ ⅓-⅔ >⅔
Score=10
6 month # risk 72%
54 year old with known breast ca

77 year old with breast cancer : 6 years bony mets (refused all treatment)
Score=10
6 month # risk 72%
Score 1 2 3
Size ⅓ ⅓-⅔ >⅔

64 year old breast ca 8 years previously: mastectomy & good response to treatment
Referred to orthopaedic clinic with thoracic back pain: bone scan requested
Developed neurological symptoms 2 weeks later

66 year old male with
Multiple Myeloma
Score 1 2 3
Size ⅓ ⅓-⅔ >⅔
Score=8
6 month # risk 15%

Score 1 2 3
Size ⅓ ⅓-⅔ >⅔
Score=10
6 month # risk 72%
2 months later

Not reconstructable- radiotherapy only

48 year old lady with known breast ca

Score 1 2 3
Size ⅓ ⅓-⅔ >⅔
Score=11
6 month # risk 96%
Already fractured

71 year old female, breast ca 1977
& 2003, 2 years elbow pain & stiffness
Score 1 2 3
Size ⅓ ⅓-⅔ >⅔
Score=7
6 month # risk 4%

Score 1 2 3
Size ⅓ ⅓-⅔ >⅔
Score=9
6 month # risk 33%

81 year old gentleman
with known prostate ca
Score 1 2 3
Size ⅓ ⅓-⅔ >⅔
Score=7
6 month # risk 4%

Spinal involvement in 80% of advanced prostate carcinoma patients &
6% develop cord compression

58 year old gentleman- fatigue & lower leg pain & swelling several months
Score 1 2 3
Size ⅓ ⅓-⅔ >⅔
Score=10
6 month # risk 72%

Feeding vessel
REFERRED FOR EMBOLISATION
Renal carcinoma cells express large amounts
of HIF and VEGF-results highly vascular bony metastases

61 year old gentleman- fatigue & lower leg pain & swelling several months
Score 1 2 3
Size ⅓ ⅓-⅔ >⅔
Score=10
6 month # risk 72%

Renal ca treated with chemotherapy: too advanced for excision

Score 1 2 3
Size ⅓ ⅓-⅔ >⅔
Score=8
6 month # risk 15%
61 year old
unknown primary

Further Reading
Clinical Orthopaedics and Related Research
Supplement October 2003

Bone metastasis dr g s patnaik

Recommended

Recommended

More Related Content

What's hot

What's hot (9)

Similar to Bone metastasis dr g s patnaik

Similar to Bone metastasis dr g s patnaik (20)

More from Narayan Medical College, Gopal Narayan Singh University

More from Narayan Medical College, Gopal Narayan Singh University (20)

Recently uploaded

Recently uploaded (20)

Bone metastasis dr g s patnaik