Successful treatment of infants with localized neuroblastoma based on their MYCN status

The aim of this study was to evaluate the effectiveness of post-surgical chemotherapy for infants with localized neuroblastoma without MYCN amplification (MNA), and determine whether risk classification using MNA is reasonable. Four hundred and fourteen eligible patients were registered between 1998 and 2004. Resectable patients in stage 1 and 2A/2B were treated by surgical resection only. Unresectable patients in stage 3 without MNA received either 6 cycles of regimen A or 3 cycles of regimen A plus 3 cycles of regimen C2; regimen A consisted of low doses of cyclophosphamide and vincristine and regimen C consisted of cyclophosphamide, vincristine and pirarubicin before surgical resection. The resectable and unresectable patients were randomly selected to receive post-surgical chemotherapy. The patients with MNA received intensive chemotherapy regimen D2, consisting of cyclophosphamide, vincristine, pirarubicin and cisplatin, and some of them received high-dose chemotherapy with stem cell transplantation. The 5-year event-free survival (5-EFS) rates of stage 1 and 2A/2B patients without MNA were 97.2 and 89.0% respectively (p = 0.02). A total of 31 patients in stage 3 without MNA received post-surgical chemotherapy, and 30 patients did not. The 5-EFS rates of these two groups (96.0 and 96.2%, respectively) were not significantly different (p = 0.869). The 5-EFS rate for localized patients with MNA (n = 6) was 50.0%, and that of patients without MNA was 95.0% (p