invasion and metastasis

Question 1

describe in situ neoplasia

Answer 1

• only applies to epithelial neoplasms
  -may progress into invasive disease
  -basmenet membrane is intact
  -screening may allow detection and treatment before developement of carcinoma

Question 2

describe carcinoma in situ

Answer 2

a malignant epithelium neoplasm that has not yet invaded through the original basement membrane

Question 3

describe invasive carcinoma

Answer 3

a carcinoma that has breached the basement membrane- it can now spread elsewhere

Question 4

describe micro invasive carcinomas

Answer 4

has breached the basement membrane but hasn’t invaded very far away from the original carcinoma

Question 5

what is the defining feature of a malignant neoplasm?

Answer 5

invasion

Question 6

what does invasion allow neoplastic cells to do?

Answer 6

spread directly through tissue and gain access to blood vessels and lymphatic channels

Question 7

what features are invasion dependant upon?

Answer 7

cellular adhesion
abnormal cellular motility
the production of enzymes with a lytic effect on the surrounding tissues

Question 8

describe metastasis

Answer 8

process by which a malignant tumour spreads from its primary site to produce secondary tumours at distant sites

Question 9

where can metastasis occur?

Answer 9

via blood vessels
lymphatics
across body cavities
along nerves
as a result of direct implantation of neoplastic cells during a surgical procedure

Question 10

what are the stages of metastatic cascade?

Answer 10

1. Detachment
2. Invasion
3. Intravasation
4. Evasion of host defences
5. Arrest
6. Extravasion
7. Vascularisation

Question 11

where does invasion occur during metastatic cascade?

Answer 11

through basement membrane

Question 12

describe the intravasation stage in the metastatic cascade

Answer 12

collagenases
cell motility

Question 13

describe the evasion of host defences stage in the metastatic cascade

Answer 13

-aggregation with platelets
- shedding of surface antigens
-adhesion to other tumour cells

Question 14

describe the extravasation stage in the metastatic cascade

Answer 14

adhesion receptors
collagenases
cell motility

Question 15

describe angiogenesis

Answer 15

once the tumour reaches 1mm in diameter they begin to grow their own blood vessels

Question 16

what is used for growth at metastatic site

Answer 16

autocrine growth factors

Question 17

give examples of angiogenesis promoters

Answer 17

1.vascular endothelial growth factors
2.basic fibroblast growth factor

Question 18

give examples of angiogenesis inhibitors

Answer 18

angiostatin
endostatin
vasculostatin

Question 19

name the different routes of metastasis

Answer 19

1. Can invade the arterial side if it grows large enough and break off
2. Haematogenous
3. Lymphatic
4. Trans-coelomic

Question 20

describe the Haematogenous route of metastasis

Answer 20

• by the blood stream
  forms secondary tumours in organs perfused by blood that has drained from a tumour

Question 21

describe the Lymphatic route of metastasis

Answer 21

lymph channels
forms secondary tumours in the regional lymph nodes

Question 22

describe the trans-coelomic route of metastasis

Answer 22

pericardial and peritoneal cavities where this invariably results in a neoplastic effusion

Question 24

Which tumours are more likely to metastasise to the lung?

Answer 24

sarcomas and any common cancers

Question 25

Which tumours are more likely to metastasise to the liver ?

Answer 25

colon , stomach ,pancreas and carcinoid tumours of intestine

Question 26

Which tumours are more likely to metastasise bone?

Answer 26

prostate, breast, thyroid, lung and kidney cancers