Evaluation of Anthracycline Effects on NT-ProBNP Plasma Level in Children with Malignancy

NT-proBNP is a marker that is released from ventricles in response to pressure and volume overload. Raised plasma level of NT-proBNP is seen in ventricular dysfunction, ventricular muscular mass reduction or ventricular ischemia. Anthracyclines are widely used in treatment of pediatric cancer but their use is associated with cardiotoxicity which increases mortality and morbidity. We measured the plasma levels of NT-proBNP to determine whether it might serve as a simple prognostic indicator of anthracycline-induced cardiotoxicity and to estimate the toxic levels of anthracyclines in children with malignancy treated with anthracycline containing regimens in Tehran’s Mofid hospital. This study was performed as a before and after clinical trial. Twenty-nine pediatric patients less than fifteen years old with newly diagnosed cancer were enrolled in this study. All patients received anthracycline-containing chemotherapy with 120 to 150 mg/m² in accumulative dose. Serial measurements of plasma NT-proBNP levels and echocardiographies were taken before onset of chemotherapy, simultaneous with accumulative dose of 120 to 150 mg/m² and two weeks after that dose. Plasma levels of NT-proBNP were within normal limits before treatment and increased significantly after the mentioned accumulative dose (P=0.002) in 26 patients out of 29. All patients had normal echocardiograms and none developed heart failure during the two-year period of the study. NT-proBNP levels increases significantly after 120 to 150 mg/m² as accumulative dose in a subset of pediatric cancer patients. This increase is not associated with echocardiographic or clinical evidence of cardiac dysfunction. Longer follow-up of these patients is necessary to determine whether NT-proBNP can be used as an early and prognostic marker for anthracycline-induced cardiotoxicity and whether 120 to 150 mg/m² as accumulative dose of anthracycline is a safe dose or not.