10. Tumour Invasion and Metastasis - Clinical Effects of Cancer

Question 1

Define the term invasion

Answer 1

Infiltration of normal tissues by malignant tumour cells with destruction of tissue.

Question 2

Define the term metastasis

Answer 2

Tumour implants discontinuous with the primary tumour.

Question 3

List the steps involved in the process of invasion

Answer 3

Abnormal or increased cell motility with loss of contact inhibition

Secretion of proteolytic enzymes

Decreased cellular adhesion

Question 4

Outline the role of metalloproteinases in invasion

Answer 4

Metalloproteinases-important for digesting through the basement membrane zone

Question 5

Define what is meant by angiogenesis

Answer 5

Formation of blood vessels

Question 6

Outline the role of angiogensis in the development of malignant tumours

Answer 6

Solid tumours cannot grow more than 1-2mm in diameter, unless they are vascularised

Tumours must generate a
de -novo blood supply

Tumours produce various factors that stimulate the formation of new blood vessels.

Question 7

Describe the stages of the metastatic cascade

Answer 7

1 DETACHMENT

2 INVASION of surrounding connective tissue

3 INTRAVASATION into lumen of vessels

4 EVASION of host defence mechanisms

5 EXTRAVASATION of cells from lumen into tissue

Question 8

What is the role of some metastatic tumours the express cell surface proteins?

Answer 8

Allow specific adhesions to endothelial cells and thus transmigration into target tissues

Question 9

List the three main routes of metastasis in the body giving clinically relevant examples

Answer 9

Through the circulatory system (Haematogenous) - blood vessels
Through the lymphatic system
Direct seeding of body cavities or surfaces (transcoelomic)

Question 10

Explain what is meant by paraneoplastic syndrome

Answer 10

Syndromes not expressed by local effect or metastases or by production of hormones indigenous to the tissue from which the tumour arose

Question 11

Give example of para-neoplastic syndrome affecting the CNS?

Answer 11

Eaton lambert syndrome

Question 12

Give example of para-neoplastic syndrome affecting skin?

Answer 12

Hypertrichosis may manifest as sudden appearance of coarse hair on the face and ears
acanthosis nigrans

Question 13

Give example of para-neoplastic syndrome affecting endocrine system?

Answer 13

Syndrome of Inappropiate Antidiuretic Hormone secretion (SIADH)

Question 14

Give example of para-neoplastic syndrome affecting musculoskeletal system?

Answer 14

Hypertrophic osteotrophy

Question 15

How do tumours present?

Answer 15

Effects of local disease (Ulcer/ bleed/ destroy)
An incidental finding eg screening (routine examinatuon)
Non-metastatic manifestation of malignancy
Consequence of distant spread

Question 16

What does hypertrophic osteoarthropathy manifest as?

Answer 16

Painful swelling of the joints

Finger clubbing