8

Question 1

Intrinsic Factors of Cancer

Answer 1

Age
Gender
Hereditary (Genetic)

Question 2

Extrinsic Factors of Cancer

Answer 2

Behavioural

• High BMI
• Low Fruit n Veg
• Low Phys Activity
• Tobacco/ Alcohol

Environmental

• Chemical
• Radiation
• Viruses

Question 3

How is a pro-carcinogen converted into a carcinogen?

Answer 3

Using cytochrome P450 in the liver

Question 4

What is a complete carcinogen (+example)

Answer 4

One that acts as both initiator and promoter

E.g. cig smoke

Question 5

How does radiation cause cancer DIRECTLY?

Answer 5

DNA damage

Question 6

How does radiation cause cancer INDIRECTLY?

Answer 6

Generates free radicals

Question 7

How do infections cause cancer DIRECTLY? (+example)

Answer 7

Affect genes that control cell growth

E.g. HPV expresses E6 prot which inhibits p53 (tumour suppressor gene)

Question 8

How do infections cause cancer INDIRECTLY? (+example)

Answer 8

Cause chronic tissue injury resulting in regen

• Regen can act as pre-existing promoter for mutations
• Or can cause new mutations from DNA rep errors

E.g. HIV reduces immunity ➡️ allows carcinogenic infections to occur

Question 9

What is the role of the RAS oncogene?

Answer 9

Encodes G proteins ➡️ relays signals ➡️ pushes cell past restric point

Encodes HER2 (GF receptors)

Encodes MYC (Transc factors)

Question 10

What do tumour supressor genes do? (+examples)

Answer 10

X passage thru restric point

E.g p53 and RB

Question 11

What causes genetic instability?

Answer 11

Chromosome segregation @ mitosis

Question 13

Describe Xeroderma Pigmentosum

Answer 13

Mutation in 1 of 7 genes that affect DNA Nucleotide Excision Repair

Question 14

Describe HNPCC (and what does it stand for?)

Answer 14

Hereditary Non-Polyposis Colon Cancer

• Colon carcinoma
• Mutation affects DNA mismatch repair

Question 15

Describe Familial Breast Cancer

Answer 15

Mutation in BRCA1 / BRCA2 genes

- Genes resp for double strand DNA break repair

Question 16

Describe Familial Retinoblastoma

Answer 16

1st Hit: Germline ➡️ Affects all body cells

2nd Hit: Somatic Mutation

Question 17

What must both hits be in Sporadic Retinoblastoma?

Answer 17

Somatic mutations & both must occur on SAME cell

No germline mut

Question 18

What is initiation?

Answer 18

First carcinogenesis stage

Mutation caused by carcinogen

Question 19

What is promotion?

Answer 19

Second carcinogenesis stage
Cell prolif ➡️ mutated cell gen
No mutation

Question 20

What is progression?

Answer 20

Third carcinogenesis stage
Transformation of benign tumour ➡️ neoplasms & malignancy
Karyotypic change (xsome number change)
Adenoma-Carcinoma sequence occurs

Question 21

What is the Adenoma-Carcinoma Sequence?

Answer 21

When cells acquire further activated oncogenes / inactivated TS
Promotes gen instability
Adenoma ➡️ Carcinoma

Question 22

What are the 6 Hallmarks of Cancer?

Answer 22

1. Self Sufficiency In Growth Signals
2. Resistant to Growth Stop Signals
3. No limit to no. of times cell can divide
4. Sustained angiogenesis ability
5. Apoptosis resistance
6. Ability to invade & prod. metastases

Question 23

Which Hallmarks of Cancer are relevant to Malignant AND Benign Neoplasms?

Answer 23

1-5

Question 24

Which Hallmarks of Cancer are relevant to Malignant Neoplasms ONLY?

Answer 24

6

Ability to Invade n prod metastases

Question 25

What are 2 occupations assoc w tumour dev

Answer 25

Asbestos exposure

Dye manufacture

Question 26

What are 2 medical conditions assoc w increased risk of malignancy?

Answer 26

Ulcerative Colitis

Cirrhosis

Question 27

What are Caretaker genes?

Answer 27

Class of TS genes that give genetic stability