Table 4.

Impact of clinical factors on event-free-survival

Clinical Characteristic	No. of Patients (events)	Relative Risk of Event	95% Confidence Interval	P-value
Sex
Male	56 (42)	1.00	---	0.001
Female	35 (14)	0.38	0.21 to 0.70
Age at diagnosis
0 - 11 years	25 (12)	1.00	---	0.512
12 - 14 years	24 (14)	1.39	0.64 to 3.01
15+ years	42 (30)	1.48	0.76 to 2.88
Race
White	54 (33)	1.00	---	0.0025
Hispanic	18 (9)	3.05	1.55 to 6.00
Black	13 (12)	1.06	0.51 to 2.22
Other	6 (2)	0.47	0.11 to 1.96
Tumor Site
Distal extremity	16 (8)	1.00	---	0.423
Proximal extremity	66 (41)	1.41	0.66 to 3.00
Axial skeleton	8 (6)	2.01	0.70 to 5.81
Not determined	1 (1)	---	---
Maximum tumor size +
< 7 cm	10 (4)	1.00	---	0.074*
≥ 7 cm but < 9 cm	12 (7)	1.03	0.41 to 2.57
≥ 9 cm but < 11 cm	20 (13)	1.17	0.54 to 2.51
≥ 11 cm	37 (23)	1.33	0.67 to 2.64
Not determined	12 (9)	---	---
Lactate dehydrogenase
Below ULN	38 (18)	1.00	---	0.0011
At or above ULN	53 (38)	2.50	1.42 to 4.40
Alkaline phosphatase
Below ULN	43 (17)	1.00	---	< 0.0001
At or above ULN	48 (39)	4.39	2.44 to 7.91
Lung Involvement
Unilateral	31 (19)	1.00	---	0.702
Bilateral	35 (20)	0.88	0.47 to 1.66
Number of Lung Nodules
1	18 (11)	1.00	---	0.460
2	13 (9)	1.22	0.50 to 2.95
3+	35 (19)	0.79	0.38 to 1.67
Site of Metastasis
Lung Only	44 (24)	1.00	---	0.0147
Bone Only	6 (6)	3.49	1.40 to 8.67
Lung + Bone Only	8 (6)	2.62	1.07 to 6.46
Soft Tissue + Other	21 (14)	1.47	0.76 to 2.86
Unknown	12 (6)	---	---

Abbreviation: ULN, upper limit of normal.

^*Log-rank trend test

⁺Maximal Tumor size determined by CT or MRI