Oncology

• What are the 3 types of tumours?

  Epithelial - all linings and glandular

  Mesenchymal - Blood vessels, structures

  Round cell - Cells of immune system, macrophages ect.
• Examples of epithelial tumours

  • Papilloma
  • Squamous cell carcinoma - curative surgery
  • Transitional cell carcinoma
  • Adenoma - benign tumour of glands.
  • Adenocarcinoma - malignant form.
• Examples of mesenchymal tumours

  • Fibroma/ Fibrosarcoma
  • Osteoma/osteosarcoma
  • Haemangioma/ Haemagniosarcoma
  • Lipoma/ Liposarcoma
  • Chondroma/ Chondrosarcoma
• Examples of round cell tumours

  • Lymphoma
  • MasT cell tumour - very common, can often fix them by doing surgery’s.
  • Plasma cell tumour - wide spectrum, can be anything from a skin mass that is benign to a malignant cancer that spread to every organ and bones.
  • Histiocytic sarcoma.
• FNA in cancer

  Fine needle aspirate.

  Easy

  Often can be done conscious in a compliant patient.

  Gives you cytology results.
• Incisional/ excisional biopsy in cancer

  Gives you more tissue.

  Usually required anaesthesia/ sedation - can get little oral polyps that you can just zip off in a very tolerant dog, but usually need to at least sedate.

  Gives you histology results.
• What is grade in tumours?

  Features of the tumour in cytology/histopathology which allow predictions to be made about the tumours behaviour.
• Features of high grade tumours

  • Higher mitotic count - dividing quicker.
  • Poorly differentiated
  • Locally invasive
  • Nuclear/cellular atypia
  • Necrosis
• What is staging?

  An assessment that combines features of the primary tumour and a measurement of where it has spread.
• Staging soft tissue sarcomas

  TNM - Tumour, Lymph node, Distant metastasis

  Stage I - small superficial low/intermediate grade tumours without nodal/distant metastasis.

  Stage II - superficially large or deep small tumours (any grade) without nodal/ distant metastasis.

  Stage III - large deep tumours without nodal/ distant metastasis.

  Stage IV - any tumour with nodal or distant metastasis.
• Types of excision of tumours

  Radical - entire compartment or structure containing mass (limb, muscle, bone).

  Curative intent - 2-3cm lateral margins and one facial plane.

  Marginal - removing all the mass within pseudo capsule. Used in a higher grade tumour when you need the wound t heal more quickly for a follow up treatment of chemo.

  Cytoreductive - take the bulk of the tumour away but leave some behind. Could be a palliative procedure, quicker healing, leaving enough skin to close. Tumour could be bleeding.

  Cytoreductive - removing the bulk of disease within pseudo capsule.

  
• Functional

  Can just be in a bad place that impedes movement or something else visible
• Bleeding

  Leaking bleeding tumour attached to blood vessels while show clinical signs
• Work out what kind of fluid it is, blood, exudate, transudate?
• Infection

  The mass can get an infection inside it causing them illness, treat the infection and their clinical signs improve
• What are the types of chemotherapy?

  Medical therapy

  Cytotoxic drugs - interferes with cell division.

  Anti-neoplastic agents

  Immunosuppressive drugs
• Effusions

  Pleural, pericardium etc can affect breathing and so on
• Paraneoplastic syndromes

  Rare but can happen. Hypercalcaemia, hyperviscosity, hormones (oestrogen), mast cell tumours (histamine, heparin)
• Pathophysiology of neoplasia
• What is a maximum tolerated dose?

  Give as much of the drug as possible in one go, hope that all the cells that are dividing at that time are hit but it, then wait to do it again.

  
• What is a Metronomic dose?

  Low dose in tablet form, to modify the immune system, down regulate the lymphocyte and interferes with the blood cell regeneration.

  
• Why use multi-agent protocols in chemo?

  Used because the side effect profiles don’t overlap, you are hitting the cancer harder. Most likely used with lymphoma as it divides so rapidly.
• What are the general side-effects of chemotherapy?

  Rapidly dividing tissues.

  Bone marrow.

  Fur/whiskers

  Gastro-intestinal tract;

  • when administering chemo, you want to give as much as possible to deal with the cancer but not as much to reduce the animals quality of life.
• Bone marrow levels during chemo

  Look for it to drop to around 2 in ideal cases. The Purple line suguests that you need to give more chemo. Anything less than 1 they are at risk of developing an infection that their body can not fight off. At this point we check their temperature and five them B-road spectrum antibiotics for 5 days to help their immune system to fight. If present with a temperature we are worries about sepsis, so immediately admit to give IVFT and IV antibiotics as the bacteria could have entered the bloodstream with the blood marrow below 1.
• Giving chemotherapy

  First stick catheters - make a hole that you then block with the catheter as the drug being administered is cytotoxic. This drug could kill the cells in that area with the hole, this could tread to an amputation. Called Extravasation. Use appropriate restraint.
• Examples of cytotoxic drugs and their side effects

  Vinicristine

  Vinblastine

  Doxorubicin

  • Binds ti DNA so is very difficult to get rid off and hard to get out. if spill then there is an antidote but does not work if not given immediately after. If been a day or 2 then have to debride the area and remove the flesh, if it is an advances case it will kill all the flesh and muscle and may have to amputate the limb.

  Cyclophosphamide - sterile haemorrhagic cystitis.
• Examples of tyrosine kinase inhibitors

  Palladian

  Masivet

  measure with:

  • Bloods
  • Urine
• Lymphoma

  Types:

  • CD8 cytotoxic killer
  • CD4 T cell
  • B cell

  Fast growing, chemo-responsive and can occur anywhere.

  Multi-centric - anatomical form, where we can find it in the body, multiple lymph nodes enlarged in the body.

  Mediastinal - arises from the thymus.

  Heptosplenic - only affecting liver and spleen.

  Alimetric - affects cats the most, gut.
• Staging lymphoma in dogs

  Stage 1 - single node or lymphoid tissue in single organ (excluding bone marrow).

  Stage 2 - regional involvement of lymph nodes (+/- tonsils).

  Stage 3 - lymph nodes affected both sides of the diaphragm.

  Stage 4 - liver and spleen involvement.

  Stage 5 - blood, bone marrow or non-lymphoid tissue affected.
• Staging lymphoma in cats

  Stage 1 - single tumour or anatomic area.

  Stage 2 - single tumour with the regional involvement, 2 nodal areas on the same side of the diaphragms, respectable GI tumour with/without regional lymph node involvement, 2 extra nodal sites.

  Stage 3 - 2 single tumours across the diaphragm, non-respectable intra-abdominal disease, para-spinal or epidural tumours.

  Stage 4 - involvement of the liver and spleen.

  Stage 5 - inolvement of the central nervous system or bone marrow.
• Types of test for tumours

  • Cytology
  • Flow cytometry
  • PARR
  • Histopathology
  • IHC (immunohistiochemostry).
• Flow cytometry in cancer

  Cells are separated by light scatter characteristics and identified via application of labelled antibodies specific for lymphoid markers. Cells from lesions obtained by multiple FNAs, results with 24-48 hours. Useful where lesions can be easily samples. Less availability then IHC as not all laboratoeries are able to run this test. Can be difficult to obtain quality samples e.g. from intestinal samples.
• PARR in tumours

  PCR test which amplifies antigen receptor genes within lymphoid cells.

  DNA either from cells or fixed tissues, results take on average 1-2 weeks. Ideally combined with other immunophenotyping diagnostics due to its variable sensitivity and specificity, especially in more challenging cases. Most useful to differentiate neoplasia from inflammatory disease.
• IHC - immunohistiochemistry

  Antibodies specific to lymphoid cell markers are applies to fixed tissue. Formalise fixed tissue, on average take 4-10 days. Widely applicable to any tissue and good sensitivity/specificity. Some limitations specifically in differentiation small cell intestinal lymphoma from IBD.