Changes in blood metabolomes as potential biomarkers for severity and prognosis in doxorubicin-induced heart failure: a study in HER2-positive and HER2-negative breast cancer patients

Abstract Background The use of doxorubicin for breast cancer treatment is often limited due to cardiotoxicity. Doxorubicin was shown to cause the alterations of cardiac metabolome levels in doxorubicin-treated rats. Interestingly, these changes were robustly associated with the development of doxorubicin-induced heart failure. Unfortunately, measurements of cardiac metabolome levels are rarely possible in humans. Hence, non-invasive biomarkers as representatives of doxorubicin-induced heart failure are required in clinical research and practice. Human epidermal growth factor receptor 2 (HER2) is a point of interest in breast cancer treatment. HER2 is associated with tumor aggressiveness. However, it was observed that HER2 protected against systemic oxidative stress and dilated cardiomyopathy. Therefore, we hypothesized that the alterations of blood metabolome levels and cardiac functions following doxorubicin treatment were different between HER2-positive and HER2-negative breast cancer patients. Purpose We determined the potential roles of changes in blood metabolomes as severity and prognostic markers of doxorubicin-induced heart failure. In addition, the changes in blood metabolomes and cardiac parameters following doxorubicin treatment in HER2-positive and HER2-negative breast cancer patients were compared. Methods HER2-positive (n=37) and HER2-negative (n=37) breast cancer patients were enrolled. Echocardiography, heart rate variability, and blood collection were performed at baseline and 2 weeks after completion of doxorubicin treatment in all patients, as well as at 3 months after completion of doxorubicin treatment in HER2-negative breast cancer patients. Blood obtained at all 3 time points was processed for measuring cardiac injury markers. Blood obtained at baseline and 2 weeks after completion of doxorubicin treatment was also processed for measuring oxidative stress in peripheral blood mononuclear cells using flow cytometry and 85 metabolome levels in plasma using mass spectrometry-based targeted metabolomics. Results Cardiac injury and systolic dysfunction at 2 weeks after completion of doxorubicin treatment were comparable between HER2-positive and HER2-negative breast cancer patients. However, only HER2-negative breast cancer patients exhibited increased systemic oxidative stress and cardiac autonomic dysfunction at this time point. Moreover, 33 and 29 blood metabolomes were altered at 2 weeks after completion of doxorubicin treatment in HER2-positive and HER2-negative breast cancer patients, respectively (Figure). Interestingly, the changes in most of these metabolomes were correlated with the changes in cardiac parameters, both at 2 weeks and 3 months after completion of doxorubicin treatment (Figure). Conclusions The changes in blood metabolomes following doxorubicin treatment were dependent on HER2 status, which might be served as severity and prognostic markers of doxorubicin-induced heart failure.