The utility of the HFA-ICOS cardiotoxicity risk assessment tool for HER2-targeted cancer therapies in patients with metastatic breast cancer: from theory to clinical practice

Abstract Background Breast cancer is the most common cancer in women. In developing countries, a considerable proportion of breast cancer diagnoses are made in advanced stages. Nevertheless, the development of targeted therapies, such as trastuzumab and other HER2 targeted agents, has revolutionized the care of these patients, leading to large improvements in disease-free and overall survival. In the other hand, these therapies are associated with cardiac dysfunction. As such, a comprehensive assessment of cardiovascular health before initiation of cancer treatment is fundamental. The HFA-ICOS´s proforma for HER2 targeted therapies is a proposed tool to evaluate the baseline risk of cardiotoxicity in these patients. Purpose To evaluate if the HFA-ICOS´s cardiotoxicity risk assessment tool for HER2-targeted cancer therapies allows to properly identify patients with HER2-positive metastatic breast cancer treated with trastuzumab at high risk for cardiotoxicity. Methods We performed an electronic chart review of patients with HER2-positive metastatic breast cancer treated with trastuzumab seen at the outpatient oncology clinic from January 2018 to December 2022. We collected the necessary data to apply the HFA-ICOS´s cardiotoxicity risk assessment tool for HER2-targeted cancer therapies, except for cardiac biomarkers. Cardiotoxicity was defined as 10% drop of left ventricular ejection fraction (LVEF) to a value of less than 50%. Results Seventy patients were included in our analysis. Mean age was 54.6+12.5 years. Cardiotoxicity was found in twenty-three patients (32%), of which, nine (39.1%) were classified at high risk for cardiotoxicity, twelve patients (52.1%) at medium risk, and two patients (8.6%) at low risk. Among the group with cardiotoxicity there was a higher proportion of older patients, obesity, borderline LVEF at baseline, prior treatment with anthracyclines, and prior exposure to radiotherapy. A high-risk score was more frequent among patients with cardiotoxicity than in those without cardiotoxicity. Most patients were classified with medium risk in both groups. The proportion of patients with low risk was not different in patients with and without cardiotoxicity. None of the variables evaluated was statistically significant. Conclusions There was a higher proportion of patients at high risk according to the HFA-ICO´s proforma for HER2 targeted therapies who developed cardiotoxicity in comparison to patients without cardiotoxicity. However, there were no significant differences in patients classified as medium or low risk. Future studies are needed to precise the most adequate method to stratify cardiotoxicity risk in patients with breast cancer exposed to anti-HER2 therapies, in order to establish effective surveillance and a suitable treatment.Table 1.