RESUMO
Introduction: Cardiotoxicity of drugs in oncology is a growing problem which cardiologists and oncologists have to struggle with. So far, researchers have been looking for biochemical markers which could help to extract a group more prone to developing complications after chemotherapy. Authors' reports are inconsistent in this topic. Aim: This study assesses the role of troponin I, CK-MB and NT-proBNP as early predictive markers for later cardiotoxicity among patients with breast cancer treated with chemotherapy. Methods: One hundred five patients with breast cancer, without either heart failure or more than moderate severity of valvular heart diseases were qualified to the study. Results: NT-proBNP concentration significantly increased just after the first cycle of chemotherapy, either in a subgroup which developed cardiotoxicity or without this end point (p<0.001, p=0.004). CK-MB did not change significantly during observation. Troponin I did not change in any of the patients. During observation HDL-cholesterol concentration significantly decreased. A transient increase of the concentration of LDL-cholesterol had been noted, but later it decreased below baseline level. Conclusion: Troponin I has too low sensitivity to be used as a prognostic marker for further cardiotoxicity after chemotherapy. No prognostic values have been noted of NT-proBNP and CK-MB due to the lack of differences in both a subgroup with and without cardiotoxicity.