L22- Behaviour of Tumours Flashcards
Malignant Tumours : What is invasion of a tumour?
Invades adjacent normal tissue
Destroys normal tissue
Malignant Tumours: What is Metastasis of a tumour?
Spreads from site of origin to distant sites and forms new tumours in these new areas
What occurs as a result of invasion?
Increased motility
Decreased adhesion
Production of proteolytic enzymes
Epithelial cells vs Mesenchymal cells in tumours
There is a Epithelial – Mesenchymal Transition when it becomes malignant
Epithelial cells are tightly connected, polarised and tethered
Mesenchymal cells loosely connected, able to migrate
In cancer epithelial cells gain mesenchymal properties and can invade and migrate
Metastasis - Routes : Lymphatic
Distant or local lymph nodes
Metastasis - Routes: Blood
Liver, lungs, bone, brain etc
Metastasis - Routes: Transcoelomic
Across peritoneal, pleural, pericardial cavities or in CSF
Metastasis - Routes: Implantation
Spillage of tumour during biopsy/surgery
What are the stages of Metastasis?
1) Detachment invasion
2) Intravasation
3) Survival Against Host defences
4) Adherence Extravasation
5) Growth
Stages of Metastasis: What is Intravasation
the invasion of cancer cells through the basal membrane into a blood or lymphatic vessel
What is the pattern of Metastasis spread between Carcinomas and Sarcomas?
Carcinomas - Lymphatic spread first
Sarcomas - Blood spread first
Where do Transcoelomic Tumours tend to metastasise to?
Ovaries
Where do Brain and adrenal Tumours tend to metastasise to?
Lungs
Bone metastasises can be….
Lytic
or
Sclerotic
Why are cancers staged and graded?
Determine Prognosis – survival time, quality of life
Decide how to treat the tumour
Research – compare therapies or prognostic factors
What are cancer stages?
How advanced is the tumour?
Has the cancer spread and if so what is the extent of spread
Has it metastasised?
What are cancer Grades?
how aggressive is the tumour?
Differentiation – how much does the tumour resemble tissue it originates from
How fast is it growing?
What are tumours graded by?
TMN system
T= Tumour - Size +/- extent of primary tumour
M= Metastases - Presence and extent of distant metastases
N= Nodes - = Presence and number of lymph node metastases
TMN can be combined to give an overall stage for the tumour —> 1 to 4
In breast cancer staging, what does Tis (Tumour stage) mean?
In situ disease
Name the stages of Dukes Staging for Colorectal Cancer ? (A—>D…gets worse as you go up the alphabet)
A = invades into, but not through bowel wall
B = invades through the bowel wall but with no lymph node metastases
C = Local lymph nodes involved
D = Distant metastases
