Cardiac function in Wilms' tumor survivors.

PURPOSE: To study late cardiac function in a single diagnostic group (children with Wilms' tumor) with good long-term survival; to compare patients treated with anthracyclines (doxorubicin) with patients treated without anthracyclines and with a normal child/adolescent group; and to examine the risk factors involved in late cardiac dysfunction. PATIENTS AND METHODS: Echocardiographic studies were performed on 97 Wilms' tumor patients treated with anthracyclines (mean cumulative dose, 303 mg/m2) with a mean follow-up time of 7.1 years, on 39 Wilms' tumor patients treated without anthracyclines with a mean follow-up time of 8.9 years, and on 50 normal subjects. Left ventricular (LV) dimensions, end systolic wall stress (a measure of afterload), and load-dependent and -independent measures of contractility were compared between groups. Potential risk factors, including age at diagnosis, follow-up duration, sex, pubertal status, cardiac irradiation, dose-intensity, and cumulative dose of anthracyclines, were studied by multivariate analysis.
RESULTS: Twenty-five percent of the anthracycline-treated group showed cardiac abnormalities. All but one of these patients had increased LV afterload. Risk factors for increased afterload were anthracycline cumulative dose (P < .05) and anthracycline dose-intensity (P < .02). Wilms' tumor patients treated without anthracyclines had thickened LV walls compared with normal subjects (P < .05).
CONCLUSION: Total dose and dose-intensity of anthracycline were risk factors for increased LV afterload in long-term Wilms' tumor survivors treated on standard protocols. The increase in afterload accounted for reduced LV shortening, whereas contractility was rarely abnormal. The new finding that Wilms' tumor survivors who do not receive anthracyclines have mild LV hypertrophy may provide some protection against anthracycline-induced cardiotoxic effects.