Cardiotoxicity in breast cancer – Are we getting to the heart of the matter?

Background: The increasing awareness of chemotherapy-related cardiotoxicity has established a unique sub-speciality – cardio-oncology. However, consensus guidelines are still emerging. Patients at risk of cardiotoxicity should be identified and managed timeously to strike the balance between adequate cancer treatment and the impact of cardiovascular side-effects.Aim: To investigate chemotherapy-induced cardiotoxicity in human epidermal growth factor receptor 2 overexpressed breast cancer patients receiving anthracyclines and/or trastuzumab.Setting: Universitas Hospital Annex, Bloemfontein, South Africa.Methods: This retrospective study was conducted at Universitas Hospital Annex during 2019 and 2020. Data collected included baseline left ventricular ejection fraction (LVEF) measurement, repeat LVEF prior to trastuzumab treatment and after cycles 3, 6, 9 and 12, and the presence of known cardiovascular risk factors.Results: Thirty-one patients were evaluated. Seven (22.6%) patients were not eligible to receive trastuzumab after anthracycline treatment, and 11 (35.5%) patients were unable to complete the intended 6 months of adjuvant trastuzumab as per departmental protocol. Overall, the majority of patients (58.1%) who were planned to receive sequential anthracycline- and trastuzumab-based therapy did not complete the intended course, because of premature cessation of trastuzumab secondary to the detection of a decreasing LVEF. No significant correlation was observed between age, being overweight, laterality (left), pre-existing hypertension, diabetes mellitus, serum albumin, smoking or cardiotoxicity.Conclusion: Cardiovascular surveillance in patients receiving potentially cardiotoxic chemotherapy is recommended, especially in our population experiencing a disproportionately higher decline in cardiac function.Contribution: The findings emphasise the impact and raise awareness of chemotherapy-related cardiotoxicity in breast cancer treatment.