Urology>>>>> Penile Cancer
Question 3#

With regards to the mechanism of action of 5 Flurouracil (5-FU) cream for erythroplasia of Queyrat (EQ). Which of the following is TRUE?

A) RNA synthesis is blocked
B) It alters the host immune system
C) DNA synthesis is blocked
D) It inhibits thymidylate reductase
E) It is an anti-tumour antibiotic

Correct Answer is C

Comment:

Answer C

Topical 5 FU is structurally similar to thymine and blocks DNA synthesis by inhibiting thymidylate synthetase. In contrast Imiquimod is an imidazoquinonin tetracyclicamine which alters the immune response by possibly inducing interferon alpha.