Mutation & Neoplasia

Question 1

Two types of Tumors

Answer 1

Benign = friendly 
Malignant = potentially fatal

Question 2

Most common (>90%) cancer

Answer 2

Carcinomas [epihetalial cell origin]

Question 3

Carcinomas

Answer 3

• Epithelial cells (they divide some continuously)
• Epithelial cancers increase in incidence as we age
• It takes many mutations to create a cancer cell & we acquire mutations over time

Question 4

3 types of Cells

Answer 4

• Labile: continuously dividing
• Stable: quiescent/inactive
• permanent: non-dividing

Question 5

Labile Cells

Answer 5

Epithelial e.g. Skin, GIT, reproductive, urinary tract, lining of exocrine ducts
Haemopoietic stem cells

Question 6

Stable Cells

Answer 6

Epithelial e.g. Liver, kidney, lung, pancreas

Smooth muscle cells, fibroblasts, endothelial cells

Question 7

Permanent Cells

Answer 7

Cardiac & skeletal myocytes, neurons

Question 8

Mutagens

Answer 8

May act directly to cause damage or may do so through increasing oxidant production or reducing anti-oxidant defences

Question 9

carcinogenesis

Answer 9

accumulating mutations

Question 10

When are benign tumors life threatening

Answer 10

in the brain

Question 11

Benign Tumors

Answer 11

• do not metastasize
• homogeneous
• well differentiated
• generally slower growing
• encapsulated

Question 12

Malignant

Answer 12

• can metastasize
• heterogeneous with different degrees of differentiation, proliferation & aggressive
• some areas grow quickly

Question 13

Sarcomas are very rare cancers but of all of the different types of sarcomas, osteosarcoma is the most common, can you explain why osteosarcomas are more commonly found in young people?

Answer 13

bones in young people are still growing & are at greater risk. when we stop growing risk diminishes

Question 14

Three ways cancer may spread?

Answer 14

1. via the blood (haematogenous)
2. via lymph (lymphatic spreading)
3. via direct seeding

Question 15

Two cellular adaptations that increase the risk of tumor development

Answer 15

Hyperplasia & Metaplasia

Question 16

what type of epithelium lines the conductive regions of the airways

Answer 16

Simple ciliated (initially pseudo-stratified columnar, then columnar then cuboidal) with goblet cells producing mucous interspersed

Question 17

The chronic irritation caused by smoking results in what type of cellular adaptations

Answer 17

The ciliated epithelium: undergoes metaplasia to become stratified squamous epithelium.
The goblet cells: undergo hyperplasia

Question 18

Which organs are frequently affected by metastatic or secondary cancers

Answer 18

Lungs: all venous blood returns to them & cancers usually spread first in the lymphatic & venous systems.
Liver:

Question 19

basic risk factors for the development of mutation & tumor genesis

Answer 19

• cell division
• hyperplasia
• metaplasia

Question 20

8 behavioral changes that occur in cancer cells as a result of multiple mutations

Answer 20

1. self-sufficieny growth signals
2. insensitivity to growth-inhibitory signals
3. evasion of apoptosis
4. defects in DNA repair
5. Limitless replicative potential
6. sustained angiogenesis
7. ability to invade & metastasize
8. predilection for glycolysis even in the presence of ocygen

Question 21

importance of early detection/ the significance of metastatic disease

Answer 21

If we catch the cancer before it has metastasised, we are able to cure the person.

Question 22

why are carcinomas the most common?

Answer 22

Epithelial cells are either labile (constantly dividing) or stable (able to divide). Epithelial cells are located on the ‘front line’ of our bodies between our inner tissues and anything entering our bodies via inhalation, ingestion etc.