Cardiotoxicity in early breast cancer: Risk factors and predictors.

e12633 Background: Breast cancer ranks second in incidence and fourth in mortality globally (GLOBOCAN 2022). Effective antineoplastic treatments have increased Cancer Therapy-Related Cardiac Dysfunction (CTRCD), impacting quality of life, morbidity, and cardiovascular mortality. This study aims to identify risk factors and predictors of chemotherapy-induced cardiotoxicity in non-metastatic breast cancer. Methods: This retrospective observational study took a sample of 504 Hispanic breast cancer patients (2012–2022) at SOLCA Hospital, Guayaquil-Ecuador. CTRCD is defined as a decline in Left Ventricular Ejection Fraction (LVEF) of >10% to an absolute value of <53% or Global Longitudinal Strain (GLS) reduction >15% per European Association of Cardiovascular Imaging (EACVI) and American Society of Echocardiography (ASE). Data analysis includes univariate (frequencies, percentages, means), paired Student's t-tests and logistic regression using SPSS v29, with significance set at p < 0.05. Results: Of 504 patients with invasive breast cancer, 46 had stage IV or unknown stage, leaving 458 for analysis. Among 135 evaluable for CTRCD, 21 developed it (11 alive, 10 deceased). Mean differences (Student’s t-test) from baseline to post-therapy were 3.96 ± 8.62 (p < 0.001) for LVEF and 1.39 ± 3.58 (p = 0.002) for GLS. Of the 458 patients for analysis, the cumulative anthracycline dose was <300 mg/m² in 157 patients, ≥300 mg/m² in 188, and none in 113. Eleven patients received anti-HER2 therapy. As cardioprotectors, 117 received Angiotensin II Receptor Blockers (ARBs), 53 Beta-Blockers (BB), and 10 Sodium-Glucose Cotransporter 2 (SGLT2) Inhibitors. No significant predictors of cardiotoxicity were found in the logistic regression analysis. Conclusions: The significant decline in LVEF and GLS post-treatment highlights the utility of these metrics in early CTRCD detection. The mortality rate among affected patients underscores the critical need for enhanced cardiac monitoring and preventive strategies. Small sample was a weakness. Baseline characteristics of patients n=458, results in frequency and (%). Age years, mean (s.d.) 53.8 (12.9) BMI * ≥ 30 155 (33.8) < 30 298 (65.1) Vascular Risk Factors Arterial Hypertension 165 (36.0) Diabetes mellitus II 72 (15.7) Smoker 7 (1.5) Dyslipidemia 193 (42.1) Coronary heart disease 6 (1.3) Initial Clinical Stage I 47 (10.3) II 248 (54.1) III 163 (35.6) Treatment Protocol FAC 55 (12.0) TAC 138 (30.1) AC/T 129 (28.2) Others 97 (21.2) Cumulative Dose of Anthracyclines ¥ mean (s.d.) 275.3 (55.8) Radiotherapy © 282 (61.6) Cardioprotector 148 (32.3) Laterality Right 228 (49.8) Left 223 (48.7) Bilateral 7 (1.5) Cardiotoxicity 21 (4.6) *kg/m 2 ; ¥ mg/m 2 ; © On left hemithorax or mediastinum; s.d.: standard deviation; BMI: Body Mass Index; FAC: 5-Fluorouracil, Adriamycin and Cyclophosphamide; TAC: Docetaxel, Adriamycin and Cyclophospha