Neoplasia Flashcards
what makes a tumor malignant?
invades surrounding tissue and/or metastasizes to other sites in the body
do benign tumors invade surrounding tissues or metastasize?
no
what is in the initiation stage of a cell becoming a tumor?
irreversible alteration of genetic material
what is the progression stage of a tumor becoming a tumor?
gradual development of features of malignancy
malignant transformation of benign tumor
hallmarks: genetic instability and tumor cell heterogeneity
what is germline mutation?
heritable mutations transmitted to offspring and present in all cells
what genetic change is predominantly responsible for tumor development?
driver mutation
what is one thing noncoding RNA has an important role in?
gene expression regulation
what are proto-oncogenes?
normal genes that regulate cell growth and differentiation
what is an oncogene?
a proto-oncogene that is activated by overexpression or mutation
what do cyclin-dependent kinases regulate?
progression of cell through cell cycle
what can a mutation in the receptor tyrosine kinase pathways lead to?
constitutive activation of growth promoting pathways
what do tumor suppressor genes control?
cell cycle
apoptosis
DNA repair
other pathways
can tumor suppressor genes prevent an oncogene from leading to cancer?
yes, if intact, through apoptosis
what is the warburg effect?
even in ample oxygen, utilizes the glycolytic pathway
less energy produced, but provides metabolic intermediates needed to synthesize cellular components
what is apoptosis induced by?
cellular stress, unregulated growth, hypoxia, misfolded proteins
p53 partially
chemotherapy and radiation
what are some important properties of tumor vessels?
leaky and tortuous
how many times can most normal cells divide before senescence?
60-70 times
what can cancer cells express to avoid senescence?
telomerase
can also produce one stem cells after division
what does the location of metastasis depend on?
tumor types, vascular drainage of tumor, tumor cell tropism to other tissues
what is the innate immune response to cancer?
least specific but immediate
natural killer cells and macrophages
what mediates the adaptive immune response to cancer?
cytotoxic T lymphocytes
what are the ways in which cancer cells can evade the immune system?
selective outgrowth of antigen-negative variants
mutation of genes involved in antigen processing or MHC presentation
direct inhibition of T cells
are M1 (pro-inflammatory) or M2 macrophages (anti-inflammatory) anti-tumor?
M1 macrophages
what are the intrinsic mechanisms of carcinogenesis?
copying errors
chromosomal abnormalities
what are the extrinsic mechanisms of carcinogenesis?
chemicals
physical agents
oncogenic viruses
what are the direct effects of neoplasia?
pressure necrosis
rupture, infarcts
what are the paraneoplastic effects of neoplasia?
cachexia
endocrinopathies
skeletal
vascular and hematologic
neurologic
gastrointestinal
what are the characteristics of an ideal fixative?
completely penetrates tissue prior to decomposition
preserves cellular morphology to allow for histologic analysis
preserves molecular integrity to allow for target detection
what is a malignant epithelial tumor called?
carcinoma
what types of cells are in round cell tumors?
lymphocytes
plasma cells
mast cells
dendritic cells
hematopoietic cells
what type of tumor are spindle cells found in?
mesenchymal tumors
what are some contagious tumors?
cervical carcinoma in humans
transmissible venereal tumor in canines
devil facial tumor disease in Tasmanian Devils
how is metastasis detection maximized in people?
sentinel lymph node mapped biopsy
one step nucleic acid amplification
what types of cancer are common in giant breed dogs?
osteosarcoma
what types of cancer are common in boxers?
cutaneous mast cell tumor
lymphoma
hemangiosarcoma
what types of cancer are common in brachycephalic dogs?
glioma
what types of cancer are common in bernese mountain dogs?
histiocytic sarcoma
what types of cancer are common in golden retrievers?
lymphoma
hemangiosarcoma
what types of cancer are common in cows, horses, and white cats?
squamous cell carcinoma
what types of cancer are common in scottish terriers and beagles?
urothelial carcinoma
what determines the grade of a malignant tumor?
degree of differentiation
what determines the stage of a malignant tumor?
extent of spread
what do cyclin-dependent kinases regulate?
progression of cell through cell cycle
what is oncometabolism?
metabolic changes that lead to abnormal DNA methylation
what does location of metastasis depend on?
tumor type
vascular drainage of tumor
tumor cell tropism to other tissues
what are two examples of cancers that spread via body cavities?
carcinomatosis
mesothelioma
what is the dominant oncogene mechanism for oncogenic viruses?
virus transfers oncogene to cells infected by virus
E6 and E7 in papillomavirus that suppress p53 protein
what is cytology better at than histology?
fine nuclear and cellular details
what is most commonly used in preserving tissue?
10% neutral buffered formalin
where is it best to take a sample of a tumor that is in a larger organ, both of which are large?
at interface between tumor and tissue: least likely to be necrotic and newest
what are the components of a tissue biopsy report?
differentiation
pleomorphism and mitoses
invasiveness and vascular invasion
margins
what are the histopathologic features of malignancy?
anisocytosis/ansiokaryosis
increased mitoses
multiple and prominent nucleoli
loss of specialized cell structures
loss of normal tissue architecture
vascular or surrounding tissue invasion
true/false: cancer cells produce two daughter cells when they divide
not always, can produce a stem cell
