Table 2.

Association of Risk Factors by Pattern of Metastases Within Age Subgroups and by Age Within Pattern of Metastases Subgroups

Unfavorable Tumor Feature	Total % of Patients* (n = 1,675)	Age (months)				Pattern of Metastases
		< 12 (n = 1,310)		12 to 18 (n = 365)		Stage 4S (n = 717)		Stage 4 (n = 958)
		4S v 4 Pattern (%)	P	4S v 4 Pattern (%)	P	Age < 12 v 12 to 18 Months (%)	P	Age < 12 v 12 to 18 Months (%)	P
MYCN amplified	21	8 v 20	< .001	39 v 48	NS	8 v 39	< .001	20 v 48	< .001
Diploidy	27	21 v 28	.0323	32 v 41	NS	21 v 32	NS	28 v 41	.0178
11q aberration	20	10 v 21	NS	38 v 34	NS	10 v 38	.06	21 v 34	NS
1p aberration	27	16 v 30	.0036	50 v 46	NS	16 v 50	.0032	30 v 46	NS
Unfavorable histology	21	7 v 23	< .001	52 v 48	NS	7 v 52	< .001	23 v 48	< .001
Grade: undifferentiated	92	93 v 90	NS	91 v 92	NS	93 v 91	NS	90 v 92	NS
High MKI	16	4 v 17	< .001	50 v 43	NS	4 v 50	< .001	17 v 43	< .001
High LDH	57	44 v 63	< .001	67 v 72	NS	44 v 67	.0059	63 v 72	NS
Adrenal primary	64	73 v 56	< .001	43 v 66	.0008	73 v 43	< .001	56 v 66	.0032
Initial treatment: chemotherapy or other intensive	79	58 v 93	< .001	100 v 92	.0476	58 v 100	< .001	93 v 92	NS

NOTE. Bold font indicates significance.

Abbreviations: LDH, lactate dehydrogenase; MKI, mitosis-karyorrhexis index; NS, not significant (P > .05).

^*No. of unknown patients excluded when calculating percentages with given characteristic.