12. Effects Of Neoplasms

Question 1

What leads to a greatly increased tumour burden?

Answer 1

Ability of malignant cells to invade and spread to distant sites

Question 2

What are the 3 steps which must occur for a metastisis to form?

Answer 2

Malignant cells must grow and invade at the primary site.
Enter a transport system and lodge at a secondary site.
Grow at the secondary site to form a new tumour (colonisation).
At all points the cells must evade destruction by immune cells.

Question 3

What 3 things are required for invasion into surrounding tissue by carcinoma cells?

Answer 3

Altered adhesion, stromal proteolysis and motility.

Question 4

What is the name for the 3 alterations that are ended for invasion of carcinoma cells into the surrounding tissue, and why is it called this?

Answer 4

Epithelial-to-mesenchymal transition.
The three changes create a carcinoma cell phenotype that sometimes appears more like a mesenchymal cell tan an epithelial cell.

Question 5

What does altered adhesion between malignant cells involve a reduction in?

Answer 5

E-cadherin expression

Question 6

What does altered adhesion between malignant cells and stromal proteins involve a change in?

Answer 6

Integrin expression

Question 7

Carcinoma cells need to degrade the basement membrane and stroma to invade. What does this involved altered expression of?

Answer 7

Protease, notably matrix metalloproteinases

Question 8

What is a cancer niche?

Answer 8

When malignant cells take advantage of nearby non-neoplastic cells, which provide some growth facts and proteases to help invasion.

Question 9

What does altered motility between malignant cells involve changes in?

Answer 9

Actin cytoskeleton

Question 10

What do malignant cells singal through?

Answer 10

Integrins, occurs via small G proteins such as members of the Rho family.

Question 11

Via what 3 routes can malignant cells reach distant sites?

Answer 11

Blood vessels entering via capillaries and venules.
Lymphatic vessels.
Fluid in body cavities eg pleura, peritoneal, pericardial and bran ventricles (transcoelomic spread).

Question 12

What is the biggest barrier to successful formation of metastases?

Answer 12

Failed colonisation

Question 13

What is the name of surfing microscopic deposits that fail to grow?

Answer 13

Micrometastases

Question 14

What is tumour dormancy?

Answer 14

An apparently disease-free person harbouring micrometastases, is why patients can have a cancer relapse

Question 15

What two things determine the site of a secondary tumour?

Answer 15

Regional drainage of blood, lymph or coelomic fluid.
Seed and soil phenomenon, which is due to interactions between between malignant cells and the local tumour environment at the secondary site.

Question 16

Where do carcinomas typically spread via first?

Answer 16

Lymphatics

Question 17

Where to sarcomas tend to spread via?

Answer 17

Blood stream

Question 18

What are the 4 commonest sites of blood borne metastasis?

Answer 18

Lung, bone, liver, brain

Question 19

Which 5 neoplasms most frequently spread to the bone?

Answer 19

Breast, bronchus, kidney, thyroid, prostate

Question 20

What is the likelihood of metastasis related to?

Answer 20

The size of the primary neoplasm (cancer staging)

Question 21

What are the effects of a neoplasm due to?

Answer 21

Direct local effects of primary and secondary neoplasms. (Most relevant for benign neoplasms).
Indirect systemic effects - effects of increasing tumour burden, secreted hormones and/or miscellaneous effects (paraneoplastic syndromes - rare disorders that are triggered by an altered immune system response to a neoplasm).

Question 22

What 4 things are the local effects of neoplasms due to?

Answer 22

Direct invasion and destruction of normal tissue.
Ulceration at a surface leading to bleeding.
Compression of adjacent structures.
Blocking tubes and orifices.

Question 23

Why do neoplasms of endocrine Gladys produce hormones?

Answer 23

Are well differentiated

Question 24

Can malignant tumours oroduce hormones?

Answer 24

Yes sometimes eg bronchial small cell carcinoma can produce ACTH

Question 25

Name 3 miscellaneous systemic effects of neoplasms

Answer 25

Neuropathies affecting the brain and peripheral nerves.
Skin problems - eg pruritis and abnormal pigmentation,
Fever.
Finger clubbing.
Myositis.

Question 26

What do increasing tumour burden and secreted factors such as cytokines contribute to in the systemic effects of neoplasms?

Answer 26

Reduced appetite and weight loss (cachexia).
Malaise.
Immunosuppression (can also be local effect due to direct bone marrow destruction).
Thrombosis.