Table 3.

Univariate and multivariate analyses of cancer-specific survival in the training cohort

Characteristics	Univariate analysis P	Multivariate analysis
		HR	95% CI	P
Sex	<0.001
Female		Reference
Male		1.164	0.931–1.456	0.183
Age (years)	<0.001
<25		Reference
>51		2.175	1.514–3.124	<0.001
25–51		1.371	0.990–1.899	0.057
Tumor site	<0.001
Axial		Reference
Extremity		0.541	0.414–0.708	<0.001
Histology	<0.001
Conventional osteosarcoma		Reference
Chondroblastic osteosarcoma		0.782	0.581–1.052	0.104
Fibroblastic osteosarcoma		0.797	0.521–1.220	0.297
Telangiectatic osteosarcoma		1.469	0.925–2.331	0.103
Osteosarcoma in Paget disease of bone		2.791	1.308–5.957	0.008
Small cell osteosarcoma		0.359	0.050–2.570	0.308
Central osteosarcoma		0.683	0.302–1.543	0.360
Intraosseous well-differentiated osteosarcoma		<0.001	0.000–6.386E+85	0.935
Parosteal osteosarcoma		0.943	0.443–2.010	0.880
Periosteal osteosarcoma		0.214	0.030–1.532	0.125
High grade surface osteosarcoma		1.102	0.154–7.906	0.923
Tumor stage	<0.001
Localized		Reference
Regional		1.782	1.326–2.397	<0.001
Distant		5.267	3.792–7.316	<0.001
Surgery	<0.001
No		Reference
Yes		0.461	0.336–0.633	<0.001
Size	<0.001
<8.9		Reference
>13.9		2.232	1.667–2.987	<0.001
8.9–13.9		1.435	1.116–1.845	0.005
Grade	<0.001
High		Reference
Low		0.502	0.320–0.787	0.03
Marital	<0.001
Married		Reference
Unmarried		1.253	0.918–1.709	0.155
Year of diagnosis	0.552
1983–1992		NI
1993–2002
2003–2014
Race	0.910
Black		NI
Other
White