Oncology: Sarcomas Flashcards
What is a sarcoma?
A malignant cancer that arises from transformed cells of mesenchymal origin
What are the names for sarcomcas of following tissues?
1. Bone
2. Connective tissue
3. Blood vessels
4. Muscle
5. Fat
6. Cartilage
- Osteosarcoma
- fibrosarcoma
- Haemangiosarcoma
- Rhabdomyosarcoma
- Liposarcoma
- Chondrosarcoma
What is the general behaviour of sarcomas?
- Locally invasive
- High metastasis- oestoesarcoma, haemangiosarcoma, histiocytic sarcoma
- Low risk- fibrosarcoma, chondrosarcoma, histocytic around joint, feline injection site
fibrosarcomas, soft tissue and peripheral nerve sheath- grade affects metastatic potential
What is the difference between grade and stage?
Stage- how far has it got (LNs)- disease burden
Grade- histological features- likely behaviour
How are primary sarcomas assessed?
- FNA- no grade
- Tru-cut biopsy
- Biopsy and histology- larger samples
- Generally what is the metastatic potential of lymph nodes?
- How do mosy sarcomas metastasise?
- What is their prediliction site for metastasis?
- Most have low metastatic potential
- Haematogenous route
- Lung
What are ideal surgical margins?
3cm lateral and 1 fascial plane beyone extent of tumour- includes FNA tract and biopsy scar
Not always possible
How are margins assessed?
- Cardinal- 3 sections
- Bread loafing- sliced bread
- Shaved margins- states of USA
Margins assessed histologically by pathologist- complete/incomplete/narrow
What classifies as narrow margins?
Less than 3mm of tissue edge
recurrence depends on tumour type and grade
What are the treatment options for microscopic residual disease (narrow/incomplete margins)
- Further wide surgical excision- treat scar as tumour
- Adjuvant radiation therapy
- Metronomic chemo
cyclophosphamide with pioxicam
What is the prognosis of resectable sarcomas?
Without metastatic disease- >4y
Prognostic factors
* Tumour grade and mitotic rate
* Tumour size
* Tumour location
* Achieveing local control
How can non-resectable tumours be treated?
- Referal surgery
- Primary radiation therapy- less effective than surgery
- Anti-metastatic treatment- not known
- What is FISS?
- How does it appear histologically?
- Feline injeciton site sarcoma
- Malignant fibroblasts, inflammation, macrophages
What is the 3,2,1 rule of FISS?
How can definite diagnosis be achieved?
- Any mass present for 3 months or longer
- Any mass greater than 2cm diameter
- Any mass that continues in size 1 month after injection
FNA may not be diagnostic- inflammator component
Incisional biopsy
How are FISS diagnosed and staged?
- Advanced imaging
- Local staging- size, margins highly invasive
- Distand staging- variably metastatic
What are the margins for FISS surgery?
3-5+ cm marhins and 2 fascial planes deep- can involve removal of spinous process or vertebrae
Still good chance of reccurence
What adjuvant treatments can be used for FISS?
- For non-resectable- pre-op radiation/chemo
- Incomplete resections- adjuvant radiation therapy
- Doxorubicin based chemo
What are the recommendations for prevention of FISS?
- Injections to be given in sites amenable to wide surgical excision
- Reduce inflammatory reactions at injection sites- avoiding irritating substances where possible
- Don’t over vaccinate
What are the clinical signs of oesteosarcoma?
Pain and lameness
* Sudden or progressive
* Localised
Swelling
How is osteosarcoma diagnosed?
Radiographic changes
* Bone lysis
* Soft tissue swelling
* New bone
* Periosteal elevation
* Long zone transition
Cytology/histo to confirm
What are the differentials for bone tumours?
- Chondrosarcoma
- Histiocytic sarcoma
- Fibrosarcoma
- Haemangiosarcoma
- Benign tumours/cysts
How are oesteosarcomas treated?
Amputation
* Most dogs tolerate amputation well
* Pain free around 1 week after
* Complete adaption take 1 months
How can pain of oesteosarcoma be treated?
- Amputation
- Analgesics- layered, multimodal
- Slow bone distruction- bisphosphonates
- Reduce sensation- radiation therapy
- Bone stabilisation
What is the protocol for gross metastasis of oesteosarcomas?
- Carboplatin or anthracyclines
- Toceranib may be helpful in presence of gross metastasis
What are the osteosarcoma prognostic factors?
Location
* Appendicular- humerus worst
* Axial- skull has low metastatic rate
Presence of metastatic disease
Total alkaline phosphatase
What is a haemangiosarcoma?
Tumour of blood vessel walls
Most commonly spleen, liver, muscle and then skin
What are the clinical signs of haemangiosarcoma and how is it diagnosed?
CS
* Shock, collapse, haemoabdomen, pericardial effusion
* Anaemia, schistocytosis
* Low platlet cound
* DIC
Diagnosis- histology
What are poor prognostic factors of haemangiosarcoma?
- Tumour rupture and bleed
- Invasive tumours in other sites
How are primary haemangiosarcomas treated?
Surgery
* Splenectomy
* Staging before splenectomy
Survival depends on stage
What is the MST for haemangiosarcoma with metastasis?
How can it be treated?
MST 4-6 weeks
Systemic chemo with anthracycline
Metronomic chemo possibly
What is a histiocytic sarcoma?
- Highly metastatic sarcoma
- Originates from histiocytes- antigen presenting cells
- Can affect: lung, spleen, liver, bone, brain, joint
What is the best therapy for good outcome of histiocytic sarcoma?
- Surgery
- radiation
- Lomustine/anthracycline chemo
