9 Neoplasm 2 Flashcards
What must malignant cells do to invade another site?
Grow and invade a primary site
Enter a transport system
Grow at a secondary site
Avoid destruction by immune cells
What does the spread of neoplasms result in?
An increased tumour burden
How must a cell change to be able to metastasise?
Altered adhesion
Stromal proteolysis
Motility
What is the epithelial-to-mesenchymal transition (EMT)?
Carcinoma cells change to have a phenotype more like a mesenchymal cell than a epithelial cell
How does adhesion change in a carcinoma cell?
E-cadherin expression is reduced
How does proteolysis alter a carcinoma cell?
The cells must degrade basement membrane and stroma to invade. Protease expression is altered
What alterations in motility does a carcinoma cell go through?
Changes in the actin skeleton
What is present in a cancer niche?
Fibroblasts, endothelial cells, inflammatory cells, stroma
How do malignant cells travel around the body?
Blood vessels
Lymphatic vessels
Fluid in body cavities eg. pleura, peritoneal, pericardial
What is the name for a clinically undetectable tumour?
Micrometastases
Why are micrometasases dangerous?
A apparant disease free patient may have tumour dormancy. The patient will relapse.
What does the site of the secondary tumour depend on?
Regional drainage of blood, lymph or coelomic fluid
Favourable cancer niche (seed and soil affect)
Where are common sites of blood-born metastases?
Lung
Bone
Liver
Brain
What is the likelihood of metastasis based on?
The size of the primary tumour
What does an increased tumour burden result in?
Reduced appetite, Weight loss, Malaise, Immunosuppression, Thrombosis
