Surgical Oncology Flashcards
What are more cancer patients cured with than any other form of treatment?
Surgery!
- The first and best chance to cure cancer is the initial surgery
- However, inappropriate surgery may make a curable cancer incurable!
What 6 questions should the vet be able to answer for the clients about their animal with cancer?
- Identify the cancer
- Explain the expected biological behaviour of the cancer
- Provide options for treatment
- Explain the quality of life before, during and after treatment
- Prognosis, with and without treatment
- Cost of treatment
At minimum, what observations should be recorded about a foreign mass?
- Use a body map to note the location of the mass
- Describe the palpable findings e.g. fixation
- Using callipers, measure the size of the tumour in 3D
- Perform a fine-needle aspirate of the mass
How do you/ your client make a decision on oncologic surgery?
Cost vs Benefits
Costs:
- Surgical morbidity
- Potential for complications
- Loss of function
- Cosmetic effects
Benefits:
- Palliation of clinical signs
- Improved survival times
What is curative intent?
All tumour surgery should be performed with curative intent
- Minimal and gentle handling of neoplastic tissue
- Irrigate wound with sterile saline to expel exfoliated cancerous cells
- Remove previous biopsy tract (if any)
- Ligate the venous drainage early to stop spread of tumour cells
- Handle and cut through normal tissue, not tumour
What are the three types of Excisions made with curative intent…
- Local Excision
- Wide local Excision
- Compartmental excision
Describe a Local Excision…
Surgical dissection plane is directly onto the tumour capsule
- Mass is ‘shelled-out’ from the surrounding tissue
Use for benign tumours only
Describe a Wide Local Excision…
For benign tumours that don’t have a distinct capsule
Excision of tumour with a margin of normal tissue
- 0.5 cm - 3-5cm wide margin
Describe a Compartmental resection…
Tumours within the soft tissue sarcoma group
- grow with aggressive invasion into local tissues
Completely remove all apparently normal tissue including blood vessels and nerves etc contained within one fascial plane
- remember to remove all three dimensions of the tumour
What must you remember about individual patients and their cancers?
- Efficacy of surgery depends on the type of cancer
- There isn’t a generic rule
- Over treatment is better than under treatment
- Every cancer’s interactions with host tissues is very different
What is cytoreductive surgery?
Surgical resection + radiotherapy and/or chemotherapy
- Can be used to avoid a disfiguring or debilitating surgery
- Decision should be made pre-op or immediately post-op
What is radiotherapy good for?
Treating microscopic disease within the tumour bed which remains following a local excision
What is palliative surgery?
Generally for cancers that have a hopeless prognosis
- removal of the tumour burden may restore/ maintain a comfortable quality of life acceptable to the owner until euthanasia is required
e. g. amputation of primary bone tumour
What is prophylactic/ preventative surgery?
Prevention of some common cancers
- e.g. testicular cancer in dogs
What is fine needle aspiration?
A diagnostic procedure involving introduction of a (22- 25) narrow- gauge, rigid hypodermic needle into a tissue or organ and removal of a small amount of tissue by suction
What are the purposes of performing a fine needle aspirate?
- To differentiate causes of organomegaly
- To differentiate among inflammation, hyperplasia and neoplasia as the cause of accessible tumours
- To differentiate benign from malignant tumours for diagnostics and therapeutics
- To differentiate carcinomas from sarcomas for diagnostics and therapeutics
What is tumour seeding?
The spillage of tumour cells and them growing as malignant implants at sites next to the original tumour
What biopsies can be performed?
- Fine needle aspiration
- Tru- cut biopsy
- Skin punch biopsy
Why is it helpful to do fine needle aspirates? But why must you keep the client in the clinic?
They are cheap
- Can do an immediate cytology pre-screening to detect any abnormal cells
If the sample is non-diagnostic, get another off the animal while its still in clinic
- Means the owner doesn’t have to go home then come back again
When do we not need to biopsy?
Splenic tumours
Liver tumours
Lung tumours
Why don’t we biopsy splenic tumours?
Obtaining accurate results by cytology or histopathology is difficult
Why don’t we biopsy liver tumours?
Prognosis is defined by the resectability of the tumour rather than any specific pathology
- Use imaging to detect resectability
Why don’t we biopsy lung tumours?
Prognosis is defined by the stage the tumour is in.
- Sampling carries additional risks
What degrees of differentiation in tumours is there?
- Well differentiated
- Moderately differentiated
- Poorly differentiated
