FABIAN 4 Flashcards
what is dysplasia?
cells look abnormal under a microscope but are not cancer
can be considered “pre-cancerous”
can be mild moderate or severe depending on how abnormal cells look under a microscope and how much of the tissue or organ is affected
may or may not become cancer and can be reversible
what is the theoretical model of tumour formation?
exponential growth
what is the actual tumour growth model?
not all tumour cells survive
some go apoptosis
selection factors
what is a factor in the incidence of cancer?
age
most human cancers develop over many decades of time
what is the basement membane and what does it do?
under the epithelial layer
epithelial cells are anchored to the basement membrane
made of extracellular matrix
supportive structure that allows epithelial cells to grow
where do pathological changes associated with colon cancer happen?
in the epithelial layer
until which point is the growth considered a polyp?
until before it reaches the basement membrane
what is a polyp?
has not reached basement membrane
can be treated and removed
very slow to grow
what is a carcinoma?
has the biological genotype and phenotype of malignancy but
has not invaded through the basement membrane
cannot metastasise in its current state
considered pre malignant/pre cancerous
as long as it is completely removed or treated the patient can be cured
what is EMT?
epithelial to mesenchymal transition
epithelial cells acquire mesenchymal phenotypes and behaviours following the down regulation of epithelial features
cells display fibroblast like morphology (loosely organised) as well as increased migratory capacity
what are normal processes where EMT happens?
embryogenesis
wound healing
what are the core EMT changes?
- cytoskeletal remodelling
- cell to cell adhesion weakening
- acquisition of cell motility (some genes are turned off/on)
- basement membrane invasion
what happens after tumour cells cross the basement membrane?
- localised invasiveness enables in situ carcinoma cells to breach the basement membrane
- intravasation into lymphatic or blood vessels
- blood vessels can transport cancer cells to distant sites
- cancer cells colonise to form metastatic tumours
cells are not the same depending on where they invade
what is MET?
mesenchymal to epithelial transition
cells can apical basal polarity, reorganise their skeleton, exhibit increased cell to cell adhesion, resulting in an organised epithelium
