Cancer Invasion and Metastasis Flashcards
When is a tumour considered to be benign?
If the neoplastic cells are clustered in a single mass
When is a tumour considered to be malignant?
Once the tumour has undergone metastasis
How many different types of tumours are there?
As many as there are different types of human cells - 200
What does the grouping of a tumour depend on?
The tissue of origin
There is increasing use of molecular definitions to stratify cancers
What are benign tumours of epithelial tissues called?
- Adenomas
- Papillomas
What are malignant tumours of epithelial cells called?
Carcinomas
What are benign connective tissue tumours called?
- Lipomas
- Fibromas
- Haemangiomas
What are malignant tumours of connective tissue called?
Sarcoma
What are benign tumours of lymphoid tissue called?
Lymphoid hyperplasia
What are malignant tumours of lymphoid tissue called?
Lymphoma
What are malignant tumours of haemopoietic tissues called?
Myeloid proliferations
What are malignant tumours of haemopoietic cells called?
Leukaemia
What are benign tumours of germ cells called?
Teratomas
What are malignant tumours of germ cells called?
Germinoma
Which of the hallmarks of cancer relate to metastasis?
- Induction of angiogenesis
- Activating invasion and metastasis
What can be determined about tumour metastasis from studies of colon carciogenesis?
Cancer is a multi-hit disease, with accumulation of genetic changes, and the transition to metastasis occurs at the end, once a lot of damage has already been done
What are the steps in the formation of a metastasise?
- Primary tumour formation
- Localised invasion
- Intravasation
- Transport through circulation
- Arrest in microvessels of various organs
- Extravasation
- Formation of micrometastasis
- Colonisation and formation of macrometasis
What allows localised invasion of a tumour?
Formation of blood vessels
What happens in tumour intravasation?
Interaction of tumour with platelets, lymphocytes, and other blood components
What must be done at all stages of metastasis?
Evasion of the immune system