Examining the risk factors for trastuzumab-related cardiotoxicity in a predominantly Hispanic South Texas population: A descriptive study.

Abstract

e24000 Background: Trastuzumab, a monoclonal antibody targeting human epidermal growth factor receptor 2 (HER2), stands as first line treatment for HER2 positive breast cancer. Despite its efficacy, trastuzumab’s association with cardiotoxicity requires monitoring via serial transthoracic echocardiograms (TTEs). We aimed to evaluate the risk factors for trastuzumab related cardiotoxicity in a South Texas population that is uniquely a majority-minority Hispanic population. Methods: A retrospective chart review study was conducted of all female patients with HER2-positive breast cancer who received trastuzumab treatment from 2015-2021. A total of 180 patients were identified. Patients without baseline TTE or a baseline left ventricle ejection fraction (LVEF) less than 53% were excluded. The final sample size included 132 patients. Cardiotoxicity was defined as a decrease in LVEF of more than 10% during the 1-year study period. Results: The mean age at the time of diagnosis in the study population was 54.2 years. The average BMI of the study participants was 30.89. The incidence of cardiotoxicity in this study population was 6%. Among those who developed cardiotoxicity, 50% had hypertension, 25% had hyperlipidemia, 12.5% had type 2 diabetes mellitus, and 12.5% had previous coronary artery bypass surgery (CABG). In terms of cancer treatment, 12.5% of patients had a history of radiation, 25% had a history of anthracycline therapy, and 12.5% had their trastuzumab treatment ended prematurely. Of the cardiotoxicity population, 37.5% patients were former smokers and 25% were former alcohol users. Hispanic/Latino patients composed 58% of the study population and represented 50% of patients who experienced cardiotoxicity. Conclusions: The incidence of trastuzumab-related cardiotoxicity in this Hispanic/Latino majority-minority population was 6%, lower than the 9% observed in a predominantly white population in our previous study. However, further studies are needed to determine the factors contributing to this reduced cardiotoxicity rate in this population.