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Breast Cancer — SCE Medical Oncology MCQ

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ModerateBreast CancerBreast CancerSCE Medical Oncology

A 55‑year‑old woman receiving adjuvant trastuzumab for HER2‑positive breast cancer develops an asymptomatic decline in left ventricular ejection fraction (LVEF) from 60% to 42% on routine echocardiography. She has no symptoms of heart failure. What is the appropriate management?

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Correct answer: A — Hold trastuzumab, start cardioprotective therapy (ACE inhibitor + beta‑blocker), repeat LVEF in 3‑4 weeks

Explanation lettering: D = shown as A · A = shown as C · E = shown as D · C = shown as E

A drop in LVEF from 60% to 42% represents a ≥10% fall to below lower limit of normal, reaching the criteria for holding HER2 therapy as per UK thresholds (see NICE TA424). Trastuzumab cardiotoxicity is usually reversible; starting ACE‑inhibitor and beta‑blocker and repeating LVEF in 3–4 weeks allows recovery and safe rechallenge. Switching to pertuzumab (A) is inappropriate; continuing trastuzumab (B) risks worsening cardiotoxicity; permanent discontinuation (C) is premature in asymptomatic and potentially reversible decline; dose reduction (E) has no evidence base.

Reference: NICE TA424 committee‑papers (cardiotoxicity thresholds) and PubMed study (safety of continuing trastuzumab with cardioprotectives), 2019, 2010