Paraneoplastic + systematic effect of neoplasia Flashcards
What’s the difference between paraneoplastic syndromes and systemic effects of cancer?
- Paraneoplastic syndromes are a consequence of cancer but not due to the location of cancer cells
- Systemic effects are consequential to the location of the tumour cells
What is cancer cachexia + anorexia? CS? Tx?
- Anaerobic respiration due glucose utilisation and tumoural hypoxia = increased lactate production and altered insulin sensitivity
- Altered metabolism due cancer related cytokines and inflammation
- Poor appetite in some patients
- Clinical signs = Weight loss, reduced fat mass, lean muscle loss = poor treatment tolerance
- Treatment =
- Maintain / intake caloric intake giving low carbohydrate high fat diet
- Omega 3 PUFA may be beneficial in reducing inflammation related changes
What can GI tumours cause? What tumours can produce hormones that damage the GIT?
- GI tumours = gastric or dudodenal ulceration =
- Bleeding can lead to anaemia as a systemic effect.
- Melena or haematoemesis occasionally seen
- Risk of rupture
- Some tumours produce hormones / metabolites = gastric acid = ulceration - PNS
- Dogs with MCT have elevated blood histamine can = GI signs, ulceration and bleeding
- Gastrinoma’s produce gastrin = GI signs, ulceration and bleeding
- Some GI neuroendocrine tumours can cause GI bleeding presumably due to hormone / cytokine production
How does PLE occur? What tumour is it seen with?
- Systemic effect
- Diffuse GI lesions can allow protein loss =
- Typically low TP, globulin and albumin often accompanied by diarrhoea
- Low albumin = ascites
- Myriad of other effects due to loss of proteins binding hormones, clotting factors etc.
- Not specific for cancer but seen particularly with GI lymphoma
What are different mechanisms of haematological effects?
- Loss
- Reduced production
- Destruction
- Cytoses
- Mono-clonal gammopathies
- Coagulation disorders
What is seen with acute blood loss anaemia?
–if no haematemesis or melena more likely splenic than GI
–TP drops before PCV
–Signs of shock
What is seen with chronic blood loss anaemia?
- Main differentials are other GI or oral lesions
- Clinical signs of lethargy, pallor
- Poorly regenerative microcytic hypochromic anaemia due to iron deficiency
- Normal or elevated platelet count
What is reduced production cytopenias?
*Anaemia of chronic inflammatory disease
* Common
* Causes include cancer, but also many other diseases.
* Mild / moderate normochromic normocytic non-regenerative anaemia.
* Anaemia due to -
1. disordered iron storage
2. shortened RBC life span
What are 2 different causes of reduced production cytopenias?
- Myelophthisis =
1. Crowding out of stem cells in the bone marrow by tumour cells
2. Some tumours produce suppressive cytokines - - Tumour types include lymphoma, leukaemias, multiple myeloma, rarely histiocytic sarcoma and mast cell tumour
- One or several cytopenias
- Neutropenia then thrombocytopenia before anaemia
- Non-regenerative normochromic normocytic anaemia
- Diagnosis by bone marrow aspirate
- Hyperoestrogenism =
- testicular tumours - 50% of dogs with Sertoli cell tumours
- Neutrophilia progressing to pancytopenia due to bone marrow hypoplasia
- Other signs are feminisation signs and include symmetrical alopecia, pendulous prepuce, hyperpigmentation, penile atrophy, gynecomastia, prostatic metaplasia
- Castration can reverse many signs but bone marrow changes can be slow to recover or irreversible
What are destruction cytopenias?
*Paraneoplastic immune mediated anaemia and thrombocytopenia
* Secondary to lymphoproliferative tumours and occasionally other tumours
* Must exclude lymphoproliferative disease before treating IMHA or IMTP
* Therapy targeted at tumour will speed resolution of signs
What is a cause of destruction cytopenia?
- Microangiopathic anaemia =
- Systemic effect
- Fragmentation and shearing of RBCs leads to anaemia
- Caused by fibrin networks
- Schistocytosis is a key indicator
What conditions are associated with schistocytosis?
- Disseminated intravascular coagulation
- Haemangiosarcoma
- IMHA
- Metastatic carcinoma
- Microangiopathic anaemia
What is paraneoplastic cytoses?
- Non-specific for cancer or any other diagnosis
- Erythrocytosis =
- Renal tumours via increased EPO, lymphoma, nasal fibrosarcoma, TVT, hepatic tumours
- Clinically significant erythrocytoses include PU/PD, neurological signs and seizures
- Treatment = phlebotomy, removal of inciting cause, hydroxyurea
- Neutrophilia =
- Seen in association with many tumours
- Can be tumour induced or an immune response to the tumour
- Eosinophilia =
- Thought to be due to IL-5 production
- Most commonly associated with T cell lymphoma and MCT
What is mono-clonal gammopathies? CS? Dx? Tx?
- Excess production of a single immunoglobulin (antibody) by tumour cells
- Elevated serum globulins on biochemistry
- Clinical signs due to hyperviscosity (neurological including seizures and coma and cardiac signs), reduced immune function, renal failure, coagulopathies and ocular disorders.
- Dx = Gammopathies detected by electrophoresis of serum and urine (Bence-Jones proteins)
- Treatment by plasmapheresis and tumour directed treatment
What can cause altered coagulation?
- Altered platelet function often seen in association with neoplasia
- Infarcts / thromboembolism can result
** Disseminated intravascular coagulation **
* Syndrome of altered consumptive coagulation
* Thromboembolism in small vessels and bleeding due to consumption of platelets and clotting factors
* Multi-organ failure and death
* Elevated APTT, PT, FDPs / D dimers, low fibrinogen, low platelet count, schistocytes
* Mainly in association with carcinoma and HSA
What tumour is associated with monoclonal gammopathies?
- Myeloma
- Leukaemia
- Lymphoma
