Neoplasia 2 Flashcards
What does invasion into surrounding tissues by a carcinoma cell require?
Altered adhesion
Stromal proteolysis
Motility
In order to metastasise, what must the cancer cells do?
- Grow and invade at the primary site
- Enter a transport system and lodge at the secondary site
- Grow at the secondary site to form a new tumour (colonisation)
What are the most lethal features of a malignant neoplasm?
Invasion and metastasis
Because the increase the tumour burden
What three alterations does invasion involve?
Altered adhesion
Stromal proteolysis
Motility
What is epithelial to mesenchymal transition?
As the cancer cell acquires the three changes required for invasion, it goes from an epithelial phenotype to a mesenchymal phenotype
What changes occur for adhesion (when talking about conditions for invasion)
Reduction in E-cadherin expression - important for adhesion between cancer cells
Changes in Integrin expression - important for adhesion between cancer cells and stroma
What type of cells can cancer cells recruit?
Fibroblasts, endothelial cells, inflammatory cells
What changes occur for proteolysis?
Altered expression of proteases such as matrix metalloproteinases (MMPs)
This is so the cell can degrade the basement membrane and stroma to invade
What are the three routes of transport to secondary sites?
Blood vessels via capillaries and venules
Lymphatic vessels
Fluid in body cavities - transcoelomic spread
What are micrometastases?
Surviving microscopic deposits of cancer cells which fail to grow
What can cause dormancy of micrometastases?
Immune system holds them in check
New niche - not adapted to a different tissue so secondary site is hostile
Cannot do angiogenesis
What determines the secondary site of a tumour?
Regional drainage of blood, lymph or coelomic fluid
What can be some systemic effects be due to in a neoplasm?
Increased tumour burden
Secretion of hormones
What are local effects of tumours due to?
Direct invasion and destruction of normal tissue
Ulceration at a surface leading to bleeding
Compression of adjacent structures
Blocking tubes and orifices
What are the effects of tumour burden?
Reduced appetite and weight loss (cachexia)
Malaise
Immunosuppression
Thrombosis
