Trastuzumab-induced cardiotoxicity in early breast cancer over a 10-year period in Uruguay.

This srudy aimed to estimate the prevalence of trastuzumab-induced cardiotoxicity in Uruguayan women diagnosed with human epidermal growth factor receptor 2 (HER2)-positive breast cancer over a 10-year period, who were treated under the financial coverage of the National Resources Fund (Fondo Nacional de Recursos). This was an observational, descriptive study based on the analysis of an anonymized database of Uruguayan women diagnosed with HER2-positive breast cancer who received adjuvant trastuzumab treatment from to 2006 to 2016, provided by the Fondo Nacional de Recursos. Statistical analysis was performed using SPSS Statistics version 25, and variables were assessed using measures of central tendency, dispersion, contingency tables, and proportions. The chi-square test was used to analyze the association between the different variables. The study included 1401 patients diagnosed with stage I to III HER2-positive breast cancer. The mean age at diagnosis was 52 years. The prevalence of cardiotoxicity was 20.3%. Most patients who discontinued treatment owing to cardiotoxicity eventually resumed treatment (92.6%). Moreover, the prevalence of cardiotoxicity was similar among patients who received regimens with and without anthracyclines. No association was observed between prior cardiovascular events or trastuzumab administration (concurrent vs sequential) and the development of cardiotoxicity. In the present study, the prevalence of cardiotoxicity was similar to that reported nationally and internationally. Most patients did not develop cardiotoxicity, while the ones who developed it remained asymptomatic and cardiotoxicity was reversible.