Veterinary Oncology Flashcards
Increasing prevalence of cancer in companion animals is due to?
increased life expectancy of pets:
- better nutrition
- vaccination for infectious disease
- preventative medicine
- leash laws
- human animal bond
Treatment of cancer in companion animals
- high incidence of disease (especially in older populations)
- informed clients
- majority are curable or controllable
- client appreciation
- professional challenge
- comparative model
- knowledge gained is shared
Behavioural classification of growth
benign -usually encapsulated -usually noninvasive -highly differentiated -rare mitoses -slow growth -little or no anaplasia -no mets Malignant -nonencapsulated -invasive -poorly differentiated -mitoses relatively common -rapid growth -variable anaplasia -metastases
Ways to take sample of tumor
fine needle aspirate
Punch biopsy
Cytogenetic abnormalities (which are much more identified in humans and barely used in dogs) include:
- deletions
- translocations
- inversions
- aneuploidy
Clonal proliferation means
cancer arises from a single cell, one which has developed a growth advantage and that has lost normal controls of proliferation
Molecular confirmation of clonality in lymphoid neoplasia
- lymphocytes (T and B) normally undergo genetic rearrangement; this creates the ability to respond to a large variety of antigens
- a malignant lymphocyte will eventually generate a large clone (same genotype) of lymphocytes
- polymerase chain reaction (PCR) can be used to amplify the variable regions of immunoglobulin genes and T-cell receptor genes
Clonality assay
- demonstrate cells are from single clone
- Ig gene in B-cells
- T-cell receptor (TCR) in T-cells
Prognosis
how will the dog respond to therapy
-dogs with B-cell lymphosarcoma do better than dogs with T-cell lymphosarcoma
Treatment modalities for cancer
local -surgery -radiation systemic -chemotherapy -radiation -immunotherapy
gene therapy
treatment of diseases with therapeutic agents that are produced in vivo from introduced genetic material
- cDNA of interest is chosen
- cell population to transfer the gene to is chosen
- delivery system is chosen
What is cancer?
Clinical definitions -tumor, neoplasm -abnormal tissue growth -variable tissue differentiation -unresponsive to normal control mechanisms Benign tumours -localised -non invasive -omas
Malignant tumors
locally invasive
induce angiogenesis
may become metastatic
carcinomas, sarcomas, leukmias
Characteristics of cancer
self sufficiency in growth signals insensitivity to antigrowth signals evading apoptosis limitless replicative potential (immortal) sustained angiogenesis tissue invasion and metastasis genomic instability
Causes of cancer
- environmental
- diet
- chemicals (hormones)
- radiation
- oncogenic viruses
- genetic factors
- trauma
