Table 2.

Summary of univariate and multivariate Cox proportional hazards model for overall survival. HR: hazards ratio; LRT: likelihood rate testing.

	Univariate LRT		Multivariate LRT
	p values and HR (95%)		p values and HR (95%)
Gender	0.771
female	Ref.
male	0.927(0.557-1.543)
Age at diagnosis	0.026
31-59 years old	Ref.			Ref.
21-30 years old	2.849(0.952-8.530)		0.038	2.268(1.065-10.029)
10-20 years old	3.686(1.322-10.283)		0.026	3.304(1.156-9.447)
Site	0.533
distal femur	Ref.
proximal tibia	0.845(0.497-1.437)
Symptom intervals	0.066		0.193
<60 days	Ref.		Ref.
>=60 days	1.622(0.969-2.715)		1.443(0.830-2.509)
Pathologic fracture	0.248
not occurred	Ref.
occurred	0.313(0.043-2.260)
Center performing the biopsy/the tumor resection	0.044		0.001
same	Ref.		Ref.
different	1.817(1.017-3.247)		2.797(1.503-5.207)
Previous medical history	0.045		0.108
no	Ref.		Ref.
yes	1.997(1.016-3.927)		1.928(0.865-4.294)
Elevated ALP at diagnosis	0.041		0.013
no	Ref.		Ref.
yes	1.678(1.022-2.756)		2.001(1.156-3.463)
Bone margin width	0.701
>=3 cm	Ref.
>=2 cm	1.157(0.549-2.436)
Neurovascular infiltration	0.049		0.182
no	Ref.		Ref.
yes	1.654(1.003-2.727)		1.479(0.832-2.628)
Tumor size	0.034		0.003
<10 cm	Ref.		Ref.
>=10 cm	1.708(1.041-2.802)		2.199 (1.311-3.690)
Histological subtypes	0.654
osteoblastic	Ref.
chondroblastic	0.765(0.347-1.688)
fibroblastic	0.458(0.111-1.884)
telengiectatic and other	0.800(0.289-2.216)
Tumor necrosis	<0.001		0.001
>=90%	Ref.		Ref.
<90%	3.504(1.827-6.720)		3.287(1.665-6.491)
Preoperative chemotherapy duration	0.019
8-12 weeks	Ref.		Ref.
>12 weeks	1.081(0.556-2.099)		0.434	0.745(0.357-1.556)
<8 weeks	2.210(1.251-3.903)		0.008	2.249(1.232-4.105)
Preoperative interval	0.701
<14 days	Ref.
>=14 days	0.906(0.547-1.501)
Postoperative interval	0.051
<=14 days	Ref.		Ref.
15-21days	1.965(0.749-5.153)		0.051	2.687(0.998-7.236)
>21 days	2.913(1.139-7.451)		0.036	2.844(1.068-7.572)