Patient characteristics
Total of 16 patients (male: female, 8:8) diagnosed as Wilms tumor were enrolled in this study, including 14 patients with relapsed disease and 2 patients with refractory disease, with median age of 4.2 years (0.5 to 11 years) at relapsed or refractory disease and median time of 17.5months (7 to 108 months) between tumor diagnosis and relapse or refractory. Most of patients had advanced-stage disease at diagnosis (stage II: N = 4, stage III: N = 6, stage IV: N = 5), and one patient had bilateral disease at diagnosis. Histology of all the patients at diagnosis was classified as FH group. These patients received 1 to 8 courses (median 3 courses) of AI regimen. All the patients received pretreated with chemotherapy, 9 patients with 2nd line and 5 patients with 3rd or more lines of pretreated chemotherapy regimen. The accumulative doses of doxorubicin were 150/m2 to 400mg/m2 (median 250mg/m2) (Table 1).