Carcinogenesis

Question 1

Types of damage within different wavelengths?

Answer 1

UVA - indirect damage

UVB - direct damage

Question 2

Which skin cancer is particularly related to the immunosuppressive consequences of sun exposure?

Answer 2

SCC

Question 3

How long is the lag peroid for presentation in Northern Europe?

Answer 3

5-10 years

Question 4

Main genetic failure that gives rise to basal cell carcinoma?

Answer 4

Hedgehog signalling

Question 5

With failures of hedgehog signalling, which pathway is most commonly affected?

Answer 5

90% - inactivated patch

10% - activated smoothened (?)

Question 6

Why is understanding hedgehog signalling important re: BCC?

Answer 6

New drugs are anatagonists of smoothened

Question 7

Problematic side effects of these drugs which affect hedgehog signalling?

Answer 7

Nasty side effects - make all food taste disgusting

Not systemic absorption required

Question 8

Common genetic defects implicated in development of SCC (not BCC)

Answer 8

p53

Question 9

Is actinic keratosis a precursor of SCC?

Answer 9

No, but marker of increased risk due to sun exposure association

(1 in 1000 develop SCC)

Question 10

Where else is hedgehog signalling important?

Answer 10

Hair growth

Question 11

When might appendage tumours not be benign?

Answer 11

Immunosuppressed patients

Question 12

Which transplant patients are at particular risk of skin cancer?

Answer 12

Cardiac

Question 13

Consequences of immunosuppression for cardiac transplant patients?

Answer 13

Glass does not protect

Avoid cyclosporin/azathiopine

Question 14

Role of HPV?

Answer 14

Difficult to determine whether causative or correlative effect of immunosuppression