AOCNP Cancer Pharmacology and Chemotherapy 1 — Questions and Answers
Question 1: Which class of chemotherapy agents acts by cross-linking DNA strands to prevent replication?
- Alkylating agents (Correct answer)
- Antimetabolites
- Vinca alkaloids
- Topoisomerase inhibitors
Correct answer: Alkylating agents
Alkylating agents (e.g., cyclophosphamide, cisplatin) form covalent cross-links within and between DNA strands, blocking replication and transcription.
Question 2: Cardiotoxicity is the major dose-limiting toxicity associated with which chemotherapy class?
- Anthracyclines (Correct answer)
- Taxanes
- Platinum compounds
- Alkylating agents
Correct answer: Anthracyclines
Anthracyclines (doxorubicin, epirubicin) cause cumulative, dose-dependent cardiomyopathy through free-radical-mediated myocyte damage.
Question 3: The mechanism of action of methotrexate is:
- Inhibition of dihydrofolate reductase, depleting folate required for DNA synthesis (Correct answer)
- Intercalation between DNA base pairs
- Binding to tubulin to prevent spindle formation
- Inhibition of topoisomerase II
Correct answer: Inhibition of dihydrofolate reductase, depleting folate required for DNA synthesis
Methotrexate inhibits DHFR, preventing reduction of folate to its active form and thereby blocking thymidylate and purine synthesis.
Question 4: Which taxane is approved for albumin-bound nanoparticle formulation to reduce hypersensitivity and improve delivery?
- Nab-paclitaxel (Abraxane) (Correct answer)
- Docetaxel
- Cabazitaxel
- Ixabepilone
Correct answer: Nab-paclitaxel (Abraxane)
Nab-paclitaxel encapsulates paclitaxel in albumin nanoparticles, eliminating the Cremophor solvent that causes hypersensitivity reactions.
Question 5: Peripheral neuropathy is the primary dose-limiting toxicity of which agent?
- Oxaliplatin (Correct answer)
- Gemcitabine
- Irinotecan
- Bleomycin
Correct answer: Oxaliplatin
Oxaliplatin causes acute cold-triggered sensory neuropathy and cumulative sensory peripheral neuropathy that limits the total dose deliverable.
Question 6: Irinotecan causes severe delayed diarrhea through which mechanism?
- Active SN-38 metabolite inhibiting topoisomerase I in intestinal epithelium (Correct answer)
- Direct mucosal alkylation
- Serotonin release in the gut
- Antimetabolite interference with enterocyte folate metabolism
Correct answer: Active SN-38 metabolite inhibiting topoisomerase I in intestinal epithelium
SN-38, the active metabolite of irinotecan, is excreted into the intestinal lumen via bile, where it damages epithelial cells causing delayed secretory diarrhea.
AOCNP Cancer Pharmacology and Chemotherapy 1
Which class of chemotherapy agents acts by cross-linking DNA strands to prevent replication?