Invasion And Metastasis 07.11.23 Flashcards
Do cancerous cells have a growth advantage over normal cells?
Yes
Carcinoma in situ meaning
Means it hasn’t reached the basement membrane so it can’t spread anywhere (lymphatics or blood vessels)
How can you easily cure carcinoma in situ?
Removal of cancerous tissue
Invasive carcinoma meaning
Cancerous cells which have invaded the basement membrane, so will be able to metastasise
Micro-invasive carcinoma meaning
Has only partially invaded the basement membrane, so lower risk of wide spread
Which proteases do cancer cells have to contain to get through the basement membrane?
Collagenase
Cathepsin D
Urokinase-type plasminogen activator
After cancer cells have penetrated the basement membrane, what do they next invade?
Extracellular matrix
To spread, where do cancer cells need to reach?
A vessel! - blood vessel (usually venous) or lymphatic vessels
Process of metastasis
Tumour growths through basement membrane —> then into stroma —> into a vessel (lymphatic or blood) —> travels via vessel (must resist immune response in vessel) —> exits vessel into stroma —> metastasis formed
How big can a metastasis get without a blood supply?
About 2mm
How does the cancer cells go through intravasation (into vessel)?
Collagenases and cell motility
How does the cancer cells go through extravasation (into vessel)?
Adhesion receptors, collagenases and cell motility
What causes growth at the metastatic site?
Growth factors
What are angiogenesis promoters?
Vascular endothelial growth factor
Basic fibroblast growth factor
What are angiogenesis inhibitors?
Angiostatin
Endostatin
Vasculostatin
Avastin medication - what does it do?
Inhibits angiogenesis by stopping VEGF-A from binding to membrane and therefore no vessels can grow
Describe route of metastasis from vena cava…
Vena cava —> heart —> lung —> gets stuck in lungs due to size of metastasis
Which tumours more commonly metastasise into the lungs?
Sarcomas and any common cancers
Define sarcoma
A malignant tumour of connective or other non-epithelial tissue
If a metastasis goes down towards the liver (e.g. a gut tumour will travel towards the liver) where does it then go?
In the liver, then through the portal vein
Which tumours more commonly metastasise to the liver?
Colon, stomach, pancreas, carcinoid tumours of the intestine
In which, liver or lungs, are you more likely to get a single metastasis? What treatment could you do?
Liver (if this was the case you could potentially remove the single metastasis)
Which tumours are commonly metastasise to bone?
Prostate (via lower spine), breast, thyroid, lung, kidney
