oncology

• Behaviour, spread and need of chemotherapy can be determined when a tumour is categorised into one of these three groups

  • epithelial
  • mesenchymal
  • round cell
• round cell tumours originate from immune cells
• mesenchymal tumours arise from structures in the body e.g., bones and blood vessel walls
• epithelial tumours arise from skin and the lining of organs and glands
• the papilloma is the benign form of what tumour type?

  squamous cell carcinoma
• -omas are benign while sarcomas are malignant
• epithelial tumours include...

  • papillomas
  • squamous cell carcinomas
  • transitional cell carcinomas
  • adenomas (glandular tissue in origin)
  • adenocarcinoma (the malignant form of glandular tissue tumours)
• Mesenchymal tumours are...

  • Fibroma / Fibrosarcoma
  • Osteoma / Osteosarcoma
  • Haemangioma / Haemangiosarcoma
  • Lipoma / Liposarcoma
  • Chondroma / Chondrosarcoma
• Round Cell Tumours include...

  • Lymphoma (malignant should be termed lymphosarcoma)
  • Mast Cell Tumour
  • Plasma Cell Tumour
  • Histiocytic Sarcoma (very aggressive)
• sarcomas are more locally invasive so require wider margins than a carcinoma
• sarcomas often affect organs with small blood vessels e.g. lungs and liver. Hence in sarcoma cases want to image these organs when staging
• carcinomas tend to go to local LN before invading other organs
• If you made a big incisional biopsy/ an excisional biopsy - you can lose the placement of the tendrils. Hence take a small sample so you can go back in and take suitable margins to remove the tendrils.

  • However if you can get large margins with an excisional you are likely to be able to cure and diagnose at the same time
• features of high grade tumours include...

  • higher mitotic count
  • nuclear / cellular atypia
  • poor differentiation
  • locally invasive
  • necrosis
• Staging = An assessment that combines features of the primary tumour and a measurement of where it as spread
• grade = Features of the tumour on cytology/histopathology which allow predictions to be made about the tumour’s behaviour
• "small superficial low/intermediate grade tumours without nodal/distant metastasis" what soft tissue sarcoma stage has been described?

  I
• "Superficially large or deep small tumours (any grade) without nodal/distant metastasis" what soft tissue sarcoma grade has been described?

  II
• "Any tumour with nodal or distant metastasis" what soft tissue sarcoma grade has been described?

  IV
• "Large deep tumours without nodal / distant metastasis" what soft tissue sarcoma grade is this?

  III
• fill in the blank

  A) radical

  B) curative intent

  C) marginal

  D) cytoreductive

  
• indications for marginal excision are...

  • High grade tumour - needs to heal quickly so you can treat it with chemotherapy

  OR

  • Not enough skin to close so need to form marginal
• paraneoplastic syndromes = Clinical signs/syndromes caused by the cancer often by releasing something into the system
• Usually in the middle of a mass there can be necrosis (far away from blood vessel) this leaves a cavity for the bacteria to reside
• Low dose of steroids just before surgery can be helpful as a mast cell tumour will bleed a lot on removal due to histamine and heparin release
• paraneoplastic syndromes include hypercalcaemia, hyperviscosity and an increase in a hormone e.g., oestrogen
• cytotoxic drugs interferes with DNA replication and hence cell division
• maximum tolerated dose chemotherapy = Give as much of the drug as possible in one go to attack the cancer, give the body time to recover and then repeat
• metronomic chemotherapy = Low dose treatment in tablet form to modify the patient's immune system. Making the patient's body more hostile to the cancer cells.

  • Doesn’t remove cancer but is a palliative option as reduces development
• multiagent protocols uses a combination of drugs which do not have overlapping side effects. this attacks the cancer harder and is commonly used with lymphoma
• chemotherapy affects the rapidly divinf tissues which are...

  • the bone marrow
  • fur and whiskers
  • dogs can lose hair while cats ose whiskers
  • the gastrointestinal tract
  • chemotherapy can trigger the vomiting sensors in the brain
  • it can also affect the intestinal lining causing diarrhoea (which often occurs 3 - 5 days after vomiting)
• Check neutrophils 7 days after chemotherapy administration - ideally want neutrophils to drop to around 1.5 - 2.
• Sally is having chemotherapy and her neutrophil count is 0.5 and she is normothermic what should you do?

  prophylactic antibiotics for 5 days
• if an animals neutrophil count drops too low during chemotherapy and they are pyrexic, there is a possibility of sepsis so start treatment. Sepsis has a better prognosis the sooner it is treated - shock bolus fluids and IV antibiotics
• extravasation is where the chemotherapeutic drug goes outside of the vein which is very painful as it causes local cell death.
• doxorubicin can cause cardiotoxicity and renal failure in cats
• why should cyclophosphamide (an oral tablet for lymphoma be given first thing in the morning?

  the product is excreted via the kidneys and can irritate the bladder, when given in the morning there is less bladder contact.
• cytostatic drugs = not directly acting on the cell cycle but is turning off the signal that division needs to occur
• TKI = tyrosine kinase inhibitor
• is lymphoma chemoresponsive?

  yes