Oncology 5 Flashcards
What do all lymphomas have in common?
They originate from lymphoreticular.
Multicentric (nodal) lymphoma…
1. Examples of clinical signs.
2. Approx. frequency in dogs.
3. Approx. frequency in cats.
- Painless lymphadenopathy, PUPD (hypercalcaemia), other non-specific signs.
- 80%.
- 20-30%.
Alimentary lymphoma…
1. Examples of clinical signs.
2. Approx. frequency in dogs.
3. Approx. frequency in cats.
- Vomiting, weight loss, diarrhoea, maybe palpably thickened intestinal loops and palpable abdominal mass.
- 7%.
- 50-70%.
Cutaneous lymphoma…
1. Examples of clinical signs.
2. Approx. frequency in dogs.
3. Approx. frequency in cats.
- Wide variety of non-specific changes – generalised or solitary. May progress from scaly alopecia to thickened erythematous ulcerative lesions. May or may not be pruritic.
- 6%.
- 0.2-3%.
Mediastinal lymphoma…
1. Examples of clinical signs.
2. Approx. frequency in dogs.
3. Approx. frequency in cats.
- Dyspnoea, tachypnoea (from space-occupying effect and/or pleural effusion), pre-caval syndrome +/- PUPD.
- 3%.
- 10-20%.
Extra-nodal e.g. bone, nasal, CNS…
1. Examples of clinical signs.
2. Approx. frequency in dogs.
3. Approx. frequency in cats.
- Site-dependent.
- 3%.
- 1-10%.
Diagnosing lymphoma.
- FNA of enlarged LNs of affected organs for cytology is frequently rewarding – avoid submandibular where possible (more likely to see a mixed picture).
- ## Biopsy if FNA non-diagnostic.
Further staging of lymphoma.
- Tailored to individual and circumstances.
- Aids decisions regarding chemotherapy.
- For prognosis: -
– Haematology.
– Biochemistry.
– Thoracic radiographs –> mediastinal mass negative prognostic factor.
– Abdominal US –> Stage III and IV = same outcome.
– FNA +/- tissue biopsy.
– immunophenotyping (immunocyto. / histochemisty).
– Bone marrow aspirate if haematological abnormalities.
WHO staging system for lymphoma.
- Firstly, anatomical site.
- Then stage:-
– I = involving single node or lymphoid tissue in single organ.
– II = involvement of multiple LNs in a region.
– III = generalised lymphadenopathy.
– IV = III plus liver/spleen involvement.
– V = blood / bone marrow involvement. - Then substage: -
– a = clinically well (w/o systemic signs).
– b = clinically unwell (w/ systemic signs).
- How do you classify lymphoma grade?
- How else can lymphoma be classified?
- small/large cell OR high/intermediate/low.
- By immunophenotype. i.e. B cell or T cell.
Classifications w/ worse prognosis.
T cell lymphomas.
Large cell type.
Higher stages.
Substage b.
Male.
Presence of hypercalcaemia.
Forms that are not multicentric.
Pre-treatment w/ steroids.
Classifications w/ better prognosis.
B cell.
Small cell type.
Lower stages.
Substage a.
Being female.
Absence of hypercalcaemia.
Multicentric form.
Avoidance of steroid pre-treatment.
CHOP protocol for lymphoma treatment.
Median survival time = 12 months.
75-90%.
25%.
COP protocol for treatment of lymphoma.
Median survival time = 6-9 months.
70-80% remission.
Single agent doxorubicin every 3 weeks protocol for lymphoma treatment.
Median survival time = 6-9 months.
Single agent prednisolone protocol for lymphoma treatment.
Median survival time = 2-3 months.
MST if no treatment.
4-6wks.
What drugs are used in CHOP protocol?
Cyclophosphamide.
Hydroxydaunorubicin (doxorubicin).
Oncovin (vincristine).
Prednisolone.
What drugs are used in COP protocol for lymphoma treatment?
Cyclophosphamide.
Oncovin (vincristine).
Prednisolone.
- ‘Positives’ to cat lymphoma.
- Negatives of cat lymphoma.
- Solitary disease more common than in dogs so surgical treatment and/or radiotherapy possible in these cases.
– Nasal lymphoma can go into prolonged remission.
– Old cats w/ ‘small cell’ alimentary lymphoma can have remission periods of 2yrs w/ ust oral prednisolone and chlorambucil. - – More likely to be substage b.
– Chemotherapy challenging due to their small size.
– Cats do not tolerate doxorubicin well.
– Generally respond less well to treatment.
– COP protocol MST = 8m and remission rates only 50-70%.
– ~30% achieve longer-lasting complete remission of >1.5yrs.
- What can resistance to lymphoma treatments be caused by?
- When is euthanasia appropriate?
- Insufficient dosing.
Failure to achieve therapeutic concentration at ‘sanctuary sites’. e.g. CNS.
Multi-drug resistance (MDP-1 gene expression).
– expression of p-glycoprotein transmembrane drug efflux pump.
– induced by pre-treatment w/ steroids. - When QoL is inadequate.
- What is leukaemia?
- 2 leukaemia subdivisions.
- Neoplastic proliferation of haemopoietic cells originating from within the bone marrow.
- Lymphoid i.e. originating from lineages of lymphocytic cells e.g. common lymphoid progenitor, NK cells, lymphocytes, plasma cells.
- Non-lymphoid (aka myeloid) e.g. originating from neutrophil, basophil, eosinophil, monocyte, megakaryocyte, mast cell and erythrocyte cell lineages.
- Lymphoid i.e. originating from lineages of lymphocytic cells e.g. common lymphoid progenitor, NK cells, lymphocytes, plasma cells.
How else can we classify leukaemia?
- Acute – poorly differentiated, generally rapid disease course.
- Chronic – well differentiated, generally insidious diseases.
Clinical signs and general features of leukaemia.
- Infiltration of neoplastic cells into bone marrow impedes production of normal haemopoietic cells.
– can cause variable degrees of ‘penias’ as seen upon haematology e.g.: -
–> Anaemia –> usually non-regenerative.
–> Thrombocytopenia.
–> Neutropenia. - High numbers of circulating neoplastic cells are usually seen (e.g. lymphocytosis) due to circulating neoplastic ‘lymphoblasts’.
- Infiltration of liver and spleen generally common.
How is a lymphoid leukaemia different to lymphoma?
Location of the cancer cells is different.
- Leukaemia – found primarily in bone marrow and blood.
- Lymphoma – exist mainly in LNs and lymph system.
Stage V lymphoma can look similar to lymphoid leukaemia, but patients w/ lymphoid leukaemia are unlikely to have significant lymphadenopathy.
Acute lymphoid leukaemia tends to affect younger patients, has a worse prognosis and is less responsive to chemo compared to lymphoma.
General diagnostic principles for leukaemia.
Haematology and blood smear examination for leukaemia.
AND
Bone marrow aspirates and bone marrow biopsy.
General treatment principles of leukaemia.
Chemotherapy.
But for chronic leukaemias, treatment may not be warranted: -
– may have no clinical signs and impact on patient welfare.
– may live like this for many years.
