Flashcards in Behaviours of Tumours Deck (50):
What are the main characteristics of malignant tumours? (3)
What is invasion?
Tumour invades adjacent tissue and destroys it.
What is metastasis?
Tumour spreads from site of origin to distant sites >> 2* tumour.
What proportion of metastases lead to death?
What causes invasion? (3)
-Proteolytic enzyme production
What are Cadherins?
>> cell to cell adhesion
What does a mutation of E-cadherin lead to?
Loss of cell-cell adhesion and contact inhibition.
What are integrins?
Proteins that attach cells to extra-cellular matrix.
What does a change in integrin expression lead to?
Decreased cell-matrix adhesion.
What are the main properties of epithelial cells? (3)
What are the main properties of mesechymal cells? (2)
-Able to migrate
What happens to cancer epithelial cells that enables them to have an increased motility?
-cancer epithelial cells gain mesenchymal properties.
-can invade and migrate
What are metalloproteinases?
>> break down proteins / degrade ECM
What type of proteolytic enzyme breaks down collagen types I-III?
What type of proteolytic enzyme breaks down collagen type IV and gelatin?
What type of proteolytic enzyme breaks down collagen type IV and proteoglycans?
Proteolytic enzymes; how are they regulated in normal tissues?
Matrix metalloproteinases = tissue inhibitors of metalloproteinases.
Why do proteolytic enzymes favour ECM breakdown in cancer?
Matrix metalloproteinases > tissue inhibitors of metalloproteinases.
How do tumours cause mechanical pressure?
Uncontrolled proliferation >> mass.
-pressure occludes vessels / tissues
What are the main metastatic routes of spread? (4)
What is transcoelomic spread?
Spread across peritoneal / pleural / pericardial cavities, or in CSF.
What is implantation?
Spread of tumour during biopsy / surgery.
What are the main sites that tumours spread to in the blood?
Via what route do carcinomas normally spread first?
Via what route do sarcomas normally spread first?
Where do bone metastases tend to originate from?
What are the main types of bone metastases? (2)
Where do transcoelomic metastases often originate from?
Where do lung tumours often metastasise to?
What is thought to affect sites of metastases?
-different tissues are more susceptible
What is angiogenesis?
Formation of new blood vessels.
-essential if metastases are to grow > 1-2mm
An increase in what type of molecule causes angiogenesis?
What type of cells produced promoters >> angiogenesis? (3)
What are the main promoters produced >> angiogenesis? (3)
What normally prevents angiogenesis?
What are the main inhibitors that prevent angiogenesis?
What is stage?
How advanced a tumour is.
-whether it has spread, and to what extent
What is grade?
How aggressive a tumour is.
-how different it looks from tissue of origin
-how fast it develops
What staging system is generally used?
TMN staging (I-IV).
-Tumour, Metastasis, Node
-differs for each organ
TMN; what does T stand for?
-size +/- extent of 1* tumour
TMN; what does M stand for?
-presence and extent
TMN; what does N stand for?
-presence and number of lymph node metastases
What are the T stages for breast cancer?
Tis = in situ
T1 = 5cm
T4 = involving skin/chest wall
What are the M stages for breast cancer?
M0 = no distant metastases
M1 = distant metastases
What are the N stages for breast cancer?
N0 = no nodes
N1 = ipsilateral nodes
N2 = >node involvement
What are the simplified stages of breast cancer?
0 = Tis
I = T1, N0, M0
II = T1-2 + M1 or T3
III = T(any) + N2, or T4
IV = T(any), N(any), M1
What type of cancer uses Dukes staging?
What are the Dukes stages? (4)
A - invades into bowel wall
B - invades through bowel wall, but no lymph nodes metastases
C - local lymph nodes
D - distant metastases
What is the 5 year survival for Dukes staging?
A = >90%
B = 70%
C = 30%
D = 5-10%