Surgical Oncology Flashcards
What 5 types of oncology surgery are available?
- Biopsy (diagnosis)
- Resection for cure (definitive excision)
- Palliation (remove clinical signs)
- Debulking (cytoreductive therapy)
- Prevention of neoplasia
> should be defined before surgery
Which sites should be biopsied for stagin?
T- tumour
N- local lymph node
M- distant metastasis
When should you biopsy?
- if outcome would change the treatement plan (Sx v chemo v radio)
- extent of treatment (conservative v aggressive)
- if owners decision would be affected (staging, grading)
- if lesion is in difficult area (head and neck, distal limb)
When is biopsy not indicated?
- if treatment plan would not be changed (mammary masses, single large lung mass)
- no change in owners willingness to treat (chest wall /limb sarcoma resection)
- if biopsy is difficult (CNS, SI, thyroid)
What information can be gained from a biopsy?
- Definitive diagnosis of neoplasia (Neoplasia vs inflammation vs other)
- Aggressiveness of neoplasia (Benign vs malignant)
- Cytologic type of neoplasia (Round cell vs epithelial vs mesenchymal)
- Histologic features (Definitive diagnosis of histological type)
- Grade of tumour (Evaluation of metastases)
- Lymph nodes/Distant metastases
What types of biopsy are possible?
> Needle -FNA - Core (eg. Trucut) > Incisional - Surgical - Grab - Punch > Excisional
What should be avoided directly onto tissue when making an excisional biopsy?
Diathermy
What should biopsies be stored in?
10% formalin
What is the aim of prophylatctic surgery?
Reduce the incidence of some tumours or the recurrence rate after treatemnet
What types of tissues may be removed prophylactically?
Normal (eg. gonads)
Abnormal (eg. pre-malignant changed tissues in SCC)
Is OHE indicated alongisde removal of mammary tumours?
> controvesrsial
- means you know any recurrence is malignant and not primary benign tumour
- you can start aggressive treatment sooner
Is removal of cryptorchid testes advocated?
- risk of surgery = risk of developing tumour in testicle
- controversial
What is the aim of definitive excision?
Use of surgery without adjunctive therapy for a complete cure
- although not 100% cells may be removed, immune system may finish the job
When is definitive excision indicated?
- localised disease
- occasionally regional mets
What must be removed if excising a tumour?
- margins in all dimensions (including deep)
- all incisional biopsy tracts
Why is it so important for the 1st surgery to be successful?
- regional anatomy normal
- less seeding
- most active and aggrrsive cells are at periphery, dirty margins leave most aggressive cells
- less normal tissue making closure more difficult
What should be carried out pre-op as preparation?
- Plan excision & reconstruction • Clip a wide area • Plan margins & stick to them • Plan reconstruction – Plan A & Plan B (redundancy in body systems – what can you throw away?) - Anticipate problems with the wound • Delayed healing • Movement • Increased wound infection -Plan analgesia protocol pre-op • Concerns about adequate analgesia should NOT dictate whether surgery is performed
How can contamination be minimised during surgery?
Avoid entering the pseudocapsule
• Contains tumour cells
Manipulate tumour gently
• Stay sutures, tissue forceps
Isolate tumour from body cavity
• Isolate with laparotomy sponges
Resect adhesions between tumour & normal tissue
• Adhesions may represent tumour invasion
Lavage the surgery site
• Tumour cells adhere via specific receptors – so little use
• BUT removes blood, necrotic tissue, foreign material
Change gloves & instruments
• Avoid seeding the surgical wound
Why is vein occlusion so important in onc surgery?
- prevents embolic spread of tumour
- arteries first probably best plan
Which LNs should be biopsied pre-op and during op?
- regional LNs pre-op
- all grossly normal LNs during op
When should LNs be excised at surgery?
- LN positive for tumour & not fixed
- LN grossly abnormal at surgery
- LN intimately attached to excised tissue
- If associated with therapeutic benefit
When is LN removal not indicated?
- LN fixed to”critical” adjacent tissue (Biopsy)
* If uncertain whether positive for tumour (Biopsy)
What is the pseudocapsule?
- zone of compressed tissue around tumour
- contains viable tumour cells so DO NOT CUT INTO !
Types of excision?
- Local
- Wide local
- Radical
> radical local
> compartmental
> muscle group
> amputation
When is local incision indicated?
- benign tumours and no local invasion (lipoma, histiocytoma, sebaceous adenoma)
- preservation of local tissue ( CNS, thyroid adenoma)
When is wide local excsision indicated?
- benign/local invasion
- malignancy/limited local invasion
eg. 1cm SCC, benign oral tumour
2-3cm MCT, ST
What is radical excision?
margins extedned into fascial planes undisturbed by tumour growth (1 or 2 fascial planes beyond gross tumour)
What are the 4 types of radical excision?
- radical local
- compartmental
- muscle group
- amputation
egs of tumour when radical excision is indicated?
• Invasive sarcomas of the abdominal or chest wall Chest or abdominal wall resection • Invasive carcinoma of the nasal planum Nasal planum resection & premaxillectomy • Invasive tumours involving eyelids Excision of eyelids & orbital contents • Invasive orbital/periorbital tumours Orbitectomy
What is compartmental excisison?
- tumour removed in a intact anatomic compartment
eg. invasive tumours in the limbs or trunk
What is muscle group excision?
- tumour removed along with the involved muscle
- no breach of fascial plane, or breach which is excised
- for small tumours involving muscle bellies
When is amputation indicated?
- Large tumours - other method not possible
- If radical excision impairs function - bone/joint excision
- Management of recurrences - disturbed fascial planes
How should samples be prepared for histology?
>Anatomically relevant • Lay out as in vivo +/- sutures >Indicate margins of interest • Closest to tumour >Methods of marking margins • Suture tag • Paint with ink • Draw a picture to orientate > Provide a history • Relevant & detailed
What can post-op histopathology tell you about the tumour?
Histological type of tumour
• Confirms pre-operative knowledge of tissue type
Histological grade of tumour
• Mitotic index, differentiation, necrosis
Regional lymph node status - access
• Staging of disease (if inaccessible pre-operatively)
Margins – adequacy of excision
• Predicts local recurrence
Vascular or lymphatic invasion
• Predicts distant metastasis
How may margin evaluation give incorrect results?
False negative
• Tumour present at margins - but not the one examined
False positive
• Tumour present - but edge examined is not a margin
Specimen incorrectly oriented
What is the aim of cytoreductive surgery?
- planned INcomplete excision of a tumour to improve the efficacy of other modalities
Indications for cytoreductive surgery?
• Essential structures (CNS tumours) • Surgical management of recurrences Unknown tumour borders • Local recurrence likely (SA distal limb) • Highly malignant tumours Vaccine-associated sarcomas
What are the 3 main PROTOCOLS of adjunctive therapy?
> pre-op: to reduce tumour bulk prior to surgery eg. sarcomas
intra-op: to allow access to tumours eg. bladder
post-op: to treat small numbers of rapidly proliferating, well oxygenated cells eg. mast cell tumour
What are the 5 main types of adjunctive therapy?
- chemotherapy
- radiation therapy
- immunotherapy
- hyperthermia
- photodynamic therapy
Indications for chemotherapy? What must be carried out prior to starting chemo?
- treat invasive or metastatic tumours not completely
removed by surgery - used before or after surgery
> debulk >90% tumour before starting
Potential complications associated with chemo?
-delayed wound healing,
vomiting, diarrhoea, nephrotox., bone marrow
suppression
When can radiation therapy be used?
Before, during or after surgery
- shrink the tumour before or destroy any remaining
cells after surgery
- potential for early or late moist desquamation or
ulceration of tissues
egs. of immunomodulatory therapy?
- interleukins, cytokines, interferons, CSF, monoclonal
antibodies - rapidly developing area of research to find very
specific effect on tumours
How is hyperthermia used in neoplastic treatments and what is it often combined with? Is this a common tx?
- locally or systemically to destroy heat sensitive tumour cells
- combined with chemo or radiation
> NOT a very practical method currently
Outline how photodynamic therapy can be used to destroy tumours
the use of various wavelengths of light to destroy
tumour cells
- sensitising agents given to the patient are taken up by
tumours cells
- the tumour is exposed to light causing a reaction with
the sensitising agent
- result is destruction of tumour cells
Aims of palliative tx?
Surgery performed to improve quality of life, for pain
relief, improved function of the affected part, or to
eliminate life-threatening complications
• Consider balance between potential gain vs morbidity!
INdications for palliative surgery?
- Tumour with metastasis
- Complete excision impossible
egs. of palliative surgery?
> Limb amputation for osteosarcoma > Splenectomy for haemangiosarcoma > Placement of a cystostomy catheter for TCC > Removal of ulcerated mammary tumours > Mandibulectomy for oral melanoma
