Table 1. Clinical and biological characteristics of the 113 patients with primary NB included in this study.

	Number	% of total
Age (year)
<1	41	36.2
>1	72	63.8
INSS stage
1	31	27.4
2	11	9.8
3	15	13.2
4	39	34.5
4s	17	15.1
MYCN status
Normal	92	81.4
Amplified	21	18.6
EFS
Yes	75	66.3
No	38	33.7
OS
Yes	87	77
No	26	23

Abbreviations: EFS=event-free survival; INSS=International Neuroblastoma Staging System; NB=neuroblastoma; OS=overall survival.