Clinical Management: Oncology Flashcards

A patient stable on imatinib for CML is started on rifampin for tuberculosis. What is the expected effect on imatinib?

Answer: Decreased imatinib exposure and possible loss of response

Rifampin strongly induces CYP3A4, which metabolizes imatinib, lowering its plasma concentrations.

Which pharmacogenomic test identifies patients at increased risk of severe or fatal toxicity from capecitabine?

Answer: DPYD genotyping

DPYD variants reduce dihydropyrimidine dehydrogenase activity, impairing fluoropyrimidine clearance and causing severe toxicity.

Why is abiraterone acetate co-administered with prednisone in metastatic prostate cancer?

Answer: To reduce mineralocorticoid excess such as hypokalemia, hypertension, and fluid retention

CYP17 inhibition raises ACTH and mineralocorticoid levels, and prednisone suppresses this compensatory effect.

Which adverse effect of ibrutinib warrants periodic cardiac monitoring and patient counseling?

Answer: Atrial fibrillation

Ibrutinib is associated with atrial fibrillation and bleeding, so palpitations should be reported and anticoagulant use carefully assessed.

Osimertinib is preferred in EGFR-mutated NSCLC partly because it is active against which resistance mutation?

Answer: EGFR T790M

Osimertinib is a third-generation EGFR TKI that inhibits both sensitizing EGFR mutations and the T790M resistance mutation.

A multiple myeloma patient begins lenalidomide plus dexamethasone. Which supportive measure is recommended?

Answer: Venous thromboembolism prophylaxis such as aspirin or LMWH based on risk

Immunomodulatory drugs combined with dexamethasone significantly increase VTE risk, requiring risk-based thromboprophylaxis.

Olaparib is most appropriately used in which patient population?

Answer: BRCA-mutated ovarian, breast, prostate, or pancreatic cancer

PARP inhibitors exploit synthetic lethality in tumors with homologous recombination deficiency such as BRCA mutations.