spinal tumours

Question 1

what are the common sites to metastasise to the spine?

Answer 1

breast
prostate
lung
renal
thyroid

Question 2

what is the effect of tumour cells on bone?

Answer 2

Lysis
- activation of the RANK/ RANKL pathway via osteoblast activation by IL1, IL6 and TNF-B

Sclerosis
- Activation of osteoblasts via the binding of endothelin-1 to the ET-A receptor and activation of WNT pathway

Question 3

how does the tumour spread to the axial skeleton?

Answer 3

via the batson’s vertebral plexus - a valveless plexus of veins allowing direct spread from organ to axial skeleton (spine, pelvis, proximal shoulder girdle and skull)

Question 4

How do tumours metastise to the spine?

Answer 4

• Intravasation - release of tumour cells from the primary tumour into blood stream
• Avoidance of immune surveillance
• Localisation and adherence to the target tissue via integrin expressed on tumour cells
• extravasation into target tissue
• induction of angiogenesis - via vascular endothelial growth factor VEGF

Question 5

how would you assess a patient with a possible MBD?

Answer 5

Triple assessment:
Focused history and examination
- oncology - hx of primary or MBD, prior and current treatment
- red flag symptoms - weight loss, night pain, night sweats, malaise
- risk factors for common cancers - smoking
- full neurological examination

Bloods
- tumour markers
- inflammatory markers
- WBC, LFT, UE

Radiological
- whole spine MRI - mets/ spinal cord compression - NICE (perform within 1 week when suspected mets
- CT TAP - primary tumour/ mets
- Xrays - endplate and disc sparing
- Bone scan - thyroid and myeloma will appear cold and may need a skeletal survey instead

Question 6

what are the treatment options for MBD?

Answer 6

• MDT approach
• NICE guidance - (MBD BOAST doesn’t cover spine)
• Based on prognosis determined by the Tokuhashi scoring system

< 6 months:
- radiotherapy 8 Gy
- External brace - suspected instability and uncontrolled pain

> 6 months:
- Decompression
- radiotherapy

Bisphosphonates
- for myeloma, breast or prostate cancer if normal analgesia insufficient
- denosab - for breast and other solid tumours excluding prostate

Question 7

what is the role of steroids for metastatic bone disease?

Answer 7

NICE guidance - commence 16mg of dexamethasone daily and reduce dosage
- monitor glucose

Question 8

what else is required as part of the work up for thyroid and renal mets?

Answer 8

thyroid and renal are vascular and need embolisation pre-operatively to reduce the risk of intraoperative bleeding

Question 9

what is the role of radiotherapy for Spinal cord compression?

Answer 9

Use
- 8Gy single fracture radiotherapy within 24hrs

Indications
- not suitable for surgical intervention
- symptom recurrence after minimum 3 months, if previous good response

Contraindication
- Complete tetra or paraplegia for 2 or more weeks and pain well controlled
- poor overall prognosis

Question 10

what bone tumours occur in the spine?

Answer 10

Intradural extramedullary
- symptoms - cord compression, night & radicular pain
- schwannoma and meningioma - associated with NFII

Intradural extramedullary
- symptoms - radicular pain, motor and sensory deficit

extradural - metastasis and lymphoma