Assessing the cardiotoxicity of Epirubicin-based chemotherapy in patients with breast cancer using high-sensitivity cardiac troponin T, N-terminal pro b-type natriuretic peptide and soluble suppression of tumorigenicity-2.

Background: Cardiac toxicity resulting in long-term complications are recognised side effect of anthracycline-based chemotherapy used in the treatment of breast cancer. Current management modality involves measurement of left ventricular ejection fraction which has inherent limitations due to its dependence on haemodynamic conditions, and inability to detect subclinical changes in left ventricular systolic function. This study aimed to evaluate changes in the concentration of cardiac biomarkers present in serum as indicators of cardiac toxicity in breast cancer patients undergoing Epirubicin-based chemotherapy.

Methods: Eighty-one breast cancer patients elected to undergo Epirubicin chemotherapy were recruited. Blood samples taken at baseline, mid-cycle and final cycle of chemotherapy were analysed for hs-cTnT, NT-proBNP and sST2. Longitudinal changes in biomarkers were compared to pre-treatment baseline values and between treatment groups.

Results: At mid-cycle, mean cumulative dose of 265 mg/m of FEC elicited a 270% change in hs-cTnT but with no significant change in NT-proBNP and sST2. At the final cycle, mean cumulative dose of 340 mg/m of FEC elicited a 565% change in hs-cTnT with no significant change in NT-proBNP and sST2. There was progressive increase in hs-cTnT from baseline with increasing cumulative dose of Epirubicin. At mid-cycle, median hs-cTnT was 7.4 ng/L (IQR: 5.6-9.3) vs. baseline of 2.0 ng/L (IQR: 2.0-4.7) < 0.001. Final cycle median hs-cTnT versus baseline was 13.3 ng/L (IQR: 8.2-22.1) vs. 2.0 ng/L (IQR: 2.0-4.7) < 0.001.

Conclusion: Serial measurement of hs-cTnT but not NT-proBNP or sST2 during Epirubicin chemotherapy has important value in the early determination cardiomyocytes damage.