The Unmonitored Heart: A Real-World Audit of Cardiac Surveillance Gaps in Left-Sided Breast Cancer Patients Receiving Anthracycline- or Trastuzumab-Based Therapy with Radiotherapy
Authors: 1. Dr Naheed Rukhsana , 2. Dr. Suriana Sultana
Institution: Delta Hospital LTD.
Introduction
Left-sided breast radiotherapy combined with anthracycline- or trastuzumab-based chemotherapy carries a well-established risk of cancer therapy-related cardiac dysfunction, and radiation-related cardiac risk rises with the dose delivered to the heart. International cardio-oncology guidelines therefore recommend baseline cardiac assessment, including left ventricular ejection fraction (LVEF), before these treatments. In real-world, resource-limited practice, how often this is done is rarely audited. We examined this gap directly.
Methods
We retrospectively reviewed 94 patient records from a single radiation and medical oncology department. Breast cancer accounted for 90 of 94 patients (95.7%). For each patient, we extracted stage, chemotherapy regimen, radiotherapy dose-fractionation, and any documented LVEF.
Results
Among the 90 breast cancer patients, the mean age was 46.3 years (range 28–71). Laterality was striking: 88 of 90 patients (97.8%) had documented left-sided disease, and none had right-sided disease. Cardiotoxic-regimen exposure was common—59 patients (65.6%) received anthracycline-based chemotherapy and 10 (11.1%) received trastuzumab-based regimens—and 86 patients (95.6%) received radical radiotherapy (2.0–2.7 Gy per fraction; 40–50 Gy in 15–25 fractions). Despite this convergence of cardiac risk factors, LVEF was documented in only 22 of 90 patients (24.4%) and in only 19 of the 61 patients (31.1%) treated with an anthracycline or trastuzumab. Only one patient had serial measurements: her LVEF fell from 48% to 28% between 2025 and 2026—a 20-point absolute decline indicating overt cardiac dysfunction—while the other 21 patients had a single recorded value of 59–80% (median 63%).
Conclusion
Left-sided, cardiotoxic-regimen exposure was common in this cohort, yet LVEF was documented in fewer than one in four patients, and serial assessment in only one. Within this small monitored subset, overt cardiotoxicity was already captured in one patient—suggesting that the true burden among the unmonitored majority may be underestimated. These findings support baseline and serial LVEF assessment as a standard component of chemoradiotherapy pathways for left-sided breast cancer, particularly in settings where formal cardio-oncology surveillance is not yet routine.