7- Bone cancers Flashcards
Bone cancers background
Metastatic bone cancer is much more common than Primary (osteosarcoma, chondrosarcoma, fibroscarcoma, Ewings)
Primary cancers:
- Rare
- Start in the bone known as bone sarcomas
- Sarcomas are cancers which start in the bone, muscle, fibrous tissue, blood vessels, fat tissue and develop anywhere in the body
types of primary bone cancer
Primary tumours arise from cells which constitute the bone and can divided into benign and malignant types
Bone forming tissues: Osteosarcoma
Cartilage forming tissues : Chondrosarcoma
Fibrous tissue: Fibrosarcoma
Marrow tumours: Ewings, Myeloma
Bone metastasis
Most common primary sites:
- Breast cancer (lytic)
- Prostate (sclerotic)
- Lung cancer (lytic)
Most common sight for bony metastases: the Spine
Management:
- tends to be palliative
- dexamethasone for MSCC
- radiotherapy
- prophylactic nailing of certain long bones if pathological fractures likely
Osteosarcoma
Background
- Most common primary bone cancer in children
- Bimodal age distribution
- Location:
1) distal femur
2) proximal tibia
Types of osteosarcoma
depend on how well-differentiated the cells are when oncogenic events occur
- Osteoblastic- most highly differentiated
- Chrondroblastic
- Fibroblastic- least highly differentiated
Risk factors for osteosarcoma
- 10-20yo
- Usually tall for age
- Males>females
- p53 mutation (Li-Fraumeni syndrome)
- RB1 mutation (familial retinoblastoma)
- Prior radiation therapy or chemotherapy
- Pagets/ osteochondromas
pathophysiology of osteosarcoma
Mutation occurs in rapidly dividing osteoblasts e.g. pubertal growth spurt
presentation of osteosarcoma
- Persistent bone pain
- Worse at night
- May wake them up
- Others:
o Bone swelling
o Palpable mass
o Restricted joint movement - Weight loss, fatigue, headache
Red flags for osteosarcoma
- Bone pain that persists and gets worse
- Wakes up from sleep
- Swelling and redness over bone
- Weak bone that fractures easily
Diffferentials: osteomyelitis or multiple myeloma
investigations for osteosarcoma
VERY URGENT XRAY within 48 hours
If Xray suggest sarcoma -> VERY URGENT SPECIALIST ASSESSMENT within 48 hours
BLOOD TESTS
- Raised alkaline phosphatase (ALP)
Other investigations
- MRI
- Bone scan
- PET
- Bone biopsy
E.g. needle biopsy or surgical biopsy during tumour excision
x-ray osteosarcoma
- Poorly defined lesion in bone, with destruction of normal bone and ‘fluffy’ appearance
- Periosteal reaction (irritation of bone lining)- “sun-burst” appearance
- Soft tissue mass
management of osteosarcoma
- Aggressive surgical resection of lesion = LIMB AMPUTATION
- Adjuvant chemotherapy improves outcomes
MDT support
o Paediatric oncologists and surgeons
o Specialist nurses
o Physiotherapy
o OT
o Psychology
o Dietician
o Prosthetics and orthotics
o SS
complications of osteosarcoma
- Leading cause of death in the young
- Pathological fractures
- Metastatic disease
Ewings sarcoma
Background
- Second most common primary bone cancer in children
- Paediatric malingnancy
- Malignancy of neural crest cell
- Most commonly occurs in bone, rare cases in soft tissue (extraosseous ewings)
- Requires aggressive treatment
- Flat bones
o Tibia
o Fibula
o Knee joint
o Femur
o Pelvis
o Ribs
risk factors for ewings sarcoma
- Males
- 10-20yo
- Caucasian
- Rare in those older than 30yo