Cancer Spread Flashcards
What are the two steps of the metastatic cascade?
Invasion of the ECM
Dissemination, homing and colonisation
What are the four steps of invasion of the ECM?
Dissociation of cancer cells from one another
Degradation of basement
Changes in attachment of tumour cells to ECM proteins
Locomotion
How do tumour cells cause the degradation of the basement membrane?
Tumour cells secrete proteolytic enzymes or induce stromal cells to secrete proteases
How do cancer cells become dissociated?
Due to alterations in intercellular adhesion molecules
What happens during locomotion?
Tumour cells are propelled through the basement membranes
What are the three steps of dissemination, homing and colonisation?
Seeding of body cavities and surfaces
Lymphatic spread
Haematogenous spread
What is the main bottleneck for metastasis?
Dissemination, due to difficulty of passing through endothelial cell barriers, lack of survival signals
What is a sentinel node?
The first node that receives lymph flow from the primary tumour
What does haematogenous spread tend to occur in?
Sarcomas
What is the seed and soil theory?
That tumours tend to metastasise in locations that are similar to the organ of origin
What is the clonal evolution model theory?
Tumour cells become heterogenous (i.e. not clones anymore) and some have greater probability of metastasising
What is the “metastasis signature” theory?
That metastatic cells develop a predilection for metastatic spread in early carcinogenesis
What is the “filter and flow” perspective?
Veins have thinner walls, therefore are more susceptible to invasion therefore metastasis follows venous flow
