Table 4.

EFS and OS of Patients With INSS Stage 2a and 2b Disease

Characteristic	No. of Patients		EFS					OS
	Stage 2a	Stage 2b	Stage 2a		Stage 2b		P	Stage 2a		Stage 2b
			5-Year EFS (%)	± SE (%)	5-Year EFS (%)	± SE (%)		5-Year OS (%)	± SE (%)	5-Year OS (%)	± SE (%)
Age, months							.2837					.0037
< 18	83	155	92	4	88	3		99	2	99	1
≥ 18	62	82	94	4	80	5		97	3	90	4
MYCN status
Not amplified	144	236	92	3	85	3		98	2	96	2
Amplified	1	0	No event		NA			No death		NA
Unknown	0	1
Histology							.0023					< .001
Favorable	115	170	91	3	90	3		98	2	99	1
Unfavorable	30	64	97	4	72	7		96	4	86	5
Unknown	0	3
Ploidy							.0129					< .001
Hyperdiploid	103	171	92	3	89	3		98	2	99	1
Diploid	34	53	91	6	75	8		97	4	84	6
Unknown	8	13

Abbreviation: EFS, event-free survival; NA, not applicable to this low-risk study; OS, overall survival.