Invasion and mets Flashcards
What does carcinoma in situ mean?
When the malignant caner cells have not yet invaded/penetrated through the BM and so are still localised
What is a micro-invasive carcinoma?
where very few cells have invaded the BM
What two factors lead to invasion of the BM?
- proteases ie matrix metalloproteinases
2. cell motility
What are the steps of the metastatic cascade?
- detachment (loss of surface adhesion molecules)
- invasion of BM
- intravasation
- evasion (of host immune defence)
- adherance and extravasation
- growth at metastatic site
- angiogenesis
What two things contribute to tumour cell motility?
- tumour cell derived motility factors
2. breakdown products of ECM
What two factors contribute to intravasation?
- collagenases
2. cell motility
What factors lead to evasion of host immune defence?
- aggregation with platelets
- shedding of surface antigens
- adhesion to other tumour cells
What factors lead to extravasation?
- adhesion receptors
- collagenases
- cell motility
What factors lead to growth at the metastatic site?
growth factors
What factors lead to angiogenesis?
- angiogenesis promotors eg VEGF and basic fibroblast growth factor
- angiogenesis inhibitors eg angiostatin, endostatin, vasculostatin
Give an example of a drug that inhibits angiogenesis and possible disadvantages
bevacizumab (Avastatin)
need angiogensis for repair and wound healing
How does an angiogenesis inhibitor work?
the monoclonal antibody binds to the angiogenesis promotors eg VEGF and prevents them binding to their receptors
Where do tumours from the gut metastasise to?
the liver via the portal vein
Give examples of tumours which metastasise to the liver
colon
stomach
pancreas
carcinoid tumour of the intestine (a rare cancer of the neuroendocrine system)
Which tumours commonly metastasise to bone?
thyroid kidney lung prostate breast
