Anthracycline antibiotics are included in the chemotherapy regimens of approximately 82% of patients with bone cancer and 44% of those with soft tissue sarcoma diagnosed in childhood or adolescence. Impaired cardiac function occurs after treatment with anthracyclines. The frequency of impairment increases with increasing cumulative dose. There are inadequate data regarding the relationship between doxorubicin administration and changes in serum levels of cardiac troponin T (cTn-T) or I (cTn-I), N-terminal (NT) brain natriuretic peptide (BNP), or tissue Doppler imaging parameters.