Table 2.

Univariate and multivariate cox regression analyses.

Characteristic	Univariate		Multivariate
	HR (95% CI)	P value	HR (95% CI)	P value
Age, per 1year increase	1.06 (1.05–1.08)	<0.001	1.09 (1.07–1.11)	<0.001
Year of diagnosis	1.05 (1.01–1.10)	0.025	1.07 (1.01–1.13)	0.017
Gender
Male	1[Reference]		1[Reference]
Female	0.83 (0.48–1.42)	0.489	0.59 (0.31–1.13)	0.110
Race
White	1[Reference]	0.189	1[Reference]
Black	0.91 (0.42–1.96)	0.809	0.76 (0.33–1.78)	0.534
Others	1.40 (0.65–3.01)	0.388	3.38 (1.31–8.69)	0.012
Tumor site
Extremity	1[Reference]	0.179	1[Reference]
Axial	1.65 (0.92–2.95)	0.094	1.98 (0.99–4.00)	0.055
Bone, NOS	2.55 (0.61–10.66)	0.198	2.08 (0.40–10.77)	0.385
Tumor size
≤70 mm	1[Reference]	0.144	1[Reference]
>70 mm	2.24 (1.23–4.06)	0.008	7.04 (2.38–20.77)	<0.001
Unknown	0.76 (0.34–1.68)	0.496	3.43 (1.22–9.62)	0.019
Tumor extension
Localized	1[Reference]		1[Reference]
Regional	2.39 (1.15–4.96)	0.020	2.64 (1.10–6.34)	0.030
Distant	5.21 (2.41–11.28)	<0.001	6.12 (2.27–16.49)	<0.001
Unknown	1.09 (0.46–2.58)	0.853	9.97 (0.33–2.84)	0.951
Surgery type
No surgery	1[Reference]		1[Reference]
Local excision	0.47 (0.23–0.95)	0.037	0.60 (0.25–1.40)	0.238
GTR	0.59 (0.30–1.19)	0.139	0.65 (0.27–1.60)	0.348
Unknown	0.44 (0.16–1.21)	0.112	1.52 (0.40–5.80)	0.544
Radiation
No	1[Reference]		1[Reference]
Yes	2.25 (1.23–4.09)	0.008	0.41 (0.18–0.89)	0.025
Unknown	∼	0.973	∼	0.976

Values in bold refers to statistical significance.

Abbreviations: HR, hazard ratio; CI, confidence interval; NOS, not otherwise specified; GTR, gross total resection.