behaviours of tumours Flashcards
define invasive tumour
Invades adjacent normal tissue
Destroys normal tissue
why do characteristics do tumours need in order to have the ability to invade
increased motility- movement
decreased adhesion
production of proteolytic enzymes.
mechanical pressure.
what molecule enables cell to cell adhesions
cadherins
what molecule enables cell to matrix adhesion
intergrin
are epithelial cells polarised, and closely connected
yes
are mesencymal cells loosely connected
yes
what change occurs in epithelial cell of a tumour which enables them to invade and migrate
epithelial cells become mesenchymal cells.
what is the function of the proteolytic enzyme matrix metalloproteinases
degrade extracellular matrix.
does cancer favour matrix metalloproteinases than tissue inhibitors of metalloproteinases, and what is the function of matrix metalloproteinases
Yes
extracellular matrix break down
what is the function of interstitial collagenases
destroy collagen types I, II, III
what is the function of gelatinises.
destroy collagen type IV, gelatin
what is the function of stomolysins
destroy collagen type IV, proteoglycans.
what effect does mechanical pressure of a tumour have
Uncontrolled proliferation forms mass
Pressure occludes vessels
Pressure atrophy
Spread along lines of least resistance
what is direct seeding method of metastases also known as
Transcoelomic- across peritoneal, plueral, pericardial cavities or CSF.
what are the 4 methods of metastases
- Lymphtics- Distant or local lymph nodes
- Blood- liver, lungs, bone brain etc
- Transcoelomic- across peritoneal, plueral, pericardial cavities or CSF.
- Implantation- spillage of tumour in biopsy or surgery.
what is the mechanical hypothesis of metastases
metastases is determined by anatomy- e.g lymphatic drainage of liver meets GI tract so tumour will spread along this route.
what is the seed and soil hypothesis
When a plant goes to seed, its seeds are carried in all directions; but they can only live and grow if they fall on congenial soil.
by which route do carcinomas metastases
lymphatic
by which route do sarcomas metastases
blood spread first.
what are the 2 types of bone metastases
lytic (lung) or sclerotic (prostate)
explain the process of angiogenesis
new vessel formation (derived from existing vessels)
role of bone marrow as this is where the endothelial stem cells are derived from.
when do tumours require the process of angiogeneisis to occur
essential if metastasis are to grow larger than 1-2 mm.
why do we stage and grade tumours
Determine Prognosis – survival time, quality of life
Decide how to treat the tumour
Research – compare therapies or prognostic factors
Stage and grade are still the best markers we have for these uses
define stage
How advanced is the tumour- prognosis
define grade
how aggressive is the tumour? How different does it look from tissue of origin.
tumour cells, stromal cells and inflammatory cells all promote which factor required in angiogenesis
VEGF
what does TNM staging stand for
- T = TUMOUR
- M = METASTASES
- N = NODES
does each organ have a individual TNF system
yes
explain what each of these stand for
T = Size +/- extent of primary tumour M = Presence and extent of distant metastases N = Presence and number of lymph node metastases
what staging is used for colorectal cancer
duke’s staging
explain the duke staging.
- 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
does survival rate decrease with metastases
Yes
what is used to determine grading
histopathologies
