Long-term cardiac effects of treatment for childhood leukemia

Abstract

Late cardiac complications in cancer survivors may develop from subclinical myocardial damage. Biochemical correlates of minimal myocardial changes can be analyzed using a commercially available rapid assay. Biomarkers are considered more sensitive markers of subclinical cardiotoxicity than conventional electrocardiographic and echocardiographic methods. The aim of this study was to determine the values of plasma N-terminal pro brain natriuretic peptide (NT-pro-BNP) and cardiac troponin T (cTnT) in asymptomatic childhood leukemia survivors after anthracycline therapy in comparison with healthy volunteers. The survivors also underwent a detailed echocardiography. Twenty six survivors of leukemia previously treated with anthracyclines with total cumulative dose 95-600 (median 221) mg/m(2) were evaluated. Analyses of cTnT and NT-proBNP from blood samples and echocardiography were performed 5-25 years after completion of therapy for childhood leukemia. Control group for biochemical analyses consisted of 22 age- and gender- matched apparently healthy volunteers. Values of NT-proBNP were significantly elevated in ANT group compared to controls (35.1 +/- 37.8 vs. 9.6 +/- 6.7 pg/ml, P<0.010). CTnT remained below the diagnostic cut-off values in both groups. All echocardiographic parameters of patients remained normal. In conclusion, differences in NT-proBNP values between patients treated with anthracyclines and healthy volunteers might signal an initial stage of anthracycline-induced myocardial damage. The potential of this biomarker to detect subclinical anthracycline-induced myocardial alterations before development of echocardiographic and clinical changes is promising.