MoD 10 Neoplasia 2

Question 1

What are the most lethal features of malignant neoplasms?

Answer 1

Ability to metastasise and invade distant sites as this greatly increases tumour burden. Benign tumours dont metastasise

Question 2

What three steps need to occur for malignant cells to get from a primary site to a secondary site? What must the cells evade at all points?

Answer 2

1. cells must grow and invade at primary site
2. cells must enter a transport system and lodge at a secondary site
3. COLONISATION- cells must grow at the secondary site to form a new tumour
   Immune destruction by immune cells

Question 3

Do cancer cells always succeed in metastasising?

Answer 3

No, it is a very inefficient process, sometimes cells woll fai lto enter a vessel and lodge at a secondary site, some cells will fail to grow at the secondary site

Question 4

What 3 alterations are needed for carcinoma cells to invade surrounding tissue?

Answer 4

Altered adhesion
Stromal proteolysis
Motility

Question 5

What do the alterations in invasion make the phenotype of the cancer cells appear like? What is this transition called?

Answer 5

Like a mesenchymal cell

Epithelial to mesenchymal transition (EMT)

Question 6

The changes in expression of which two proteins alters adhesion in malignant cells?

Answer 6

E-cadherin

Integrin

Question 7

What do cancer cells break down to invade? What performs this proteolysis?

Answer 7

Basement membrane and stroma

Altered expression of matrix metalloproteinases (MMPs)

Question 8

What forms a cancer niche?

Answer 8

The nearby non-neoplastic cells that malignant cells take advantage of
Stroma
Fibroblasts
Endothelial cells
Inflammatory cells

Question 9

What changes to alter motility of invading cells?

Answer 9

Actin cytoskeleton changes

Signalling through integrins important (via G proteins in Rho family)

Question 10

In what 3 ways can malignant cells spread to distant sites?

Answer 10

1. Through blood vessels via capillaries and venules
2. Through the lymphatic vessels
3. Through fluid in body cavities (pleura, peritoneal, pericardial and brain ventricles), known as TRANSCOELOMIC SPREAD

Question 11

What two things must happen at the secondary site for a clinical tumour to form?

Answer 11

Malignant cells must get out of vessel (extravasation)

Malignant cells must colonise

Question 12

What are micrometastases?

Answer 12

Microscopic tumour cell deposits at secondary sites that survive but fail to grow into clinically detectable tumours

Question 13

Explain tumour dormancy

Answer 13

When an apparently disease free person harbours micrometastases they have no symptoms until a time after when/if these metastases then start to grow

Question 14

What factors can cause tumour dormancy?

Answer 14

Immune attack
Reduced angiogenesis
Hostile secondary site

Question 15

What does secondary site of neoplasm depend on?

Answer 15

Regoinal drainage of lymph (regional lymph node) blood(next capillary bed enters) or coelomic fluid (elsewhere in coelomic space or adjacent organs)

Question 16

Where are the most likely metastases of each type of transport system?

Answer 16

Lymphatic: regional lymph node
Coelom: elsewhere in coelom
Blood: lung and liver (first capillary beds encountered) bone, brain

Question 17

Why do the sites of blood borne metastases often seem unpredictable?

Answer 17

“seed and soil” phenomenon, due to interactions between malignant cells and niche at secondary site. Niche might not suit those malignant cells so they dont grown there etc.

Question 18

What neoplasms most frequently spread to bone?

Answer 18

breast, bronchus, kidney, thyroid and prostate

Question 19

Do all malignant neoplasms metastasise?

Answer 19

No, some are aggressive and metastasise early and others almost never metastasise. Likelihood of metastasis is related to the size of the primary neoplasm

Question 20

What is the basis of cancer staging?

Answer 20

The size of the primary neoplasm as this relates to likelihood of metastasis

Question 21

Give an example of an aggressive malignant neoplasm that metastasises early and one that almost never metastasises

Answer 21

aggressive- small cell bronchial carcinoma

rarely metastasises- basal cell carcinoma

Question 22

What two types of effects can neoplasms have?

Answer 22

Local in areas of primary and secondary tumours

Systemic from increased tumour burden, secreted hormones and misc. effects

Question 23

What are having systemic effects of neoplasms called?

Answer 23

Paraneoplastic syndrome

Question 24

What effects are most relevant in benign tumours?

Answer 24

Local effects from primary and hormonal effects

Question 25

What are some local effects of tumours?

Answer 25

Direct invasion and destruction of normal tissue
Ulceration at a surface leading to bleeding
Compression of adjacent structures which can block vessels
Blockage of tubes and orifices from the inside

Question 26

What symptoms can increasing tumour burden give?

Answer 26

Reduced appetite and weight loss (cachexia), malaise (feeling generally unwell), immunosupression (can also be due to BM destruction) and thrombosis

Question 27

Why do benign endocrine tumours typically secrete hormones?

Answer 27

They are well differentiated

Question 28

What hormone can squamous cell carcinoma produce?

Answer 28

PTH-like hormone

Question 29

What hormones can bronchial small cell carcinoma produce?

Answer 29

ACTH or ADH

Question 30

Give some examples of miscellaneous systemic effects that can be caused by neoplasms

Answer 30

Neuropathoes affecting the brain and peripheral nerves, skin problems e.g pruritis (itching) and abnormal pigmentation, fever, myositis(muscle inflammation)