Table 4.

Multivariate analyses for OS and CSS for osteosarcoma patients aged over 40

Variable	Primary					Secondary
	OS		CSS			OS
	Hazard Ratio(95% CI)	P value	Hazard Ratio(95% CI)	P value		Hazard Ratio(95% CI)	P value
Age (years)
≤60	1		1			1
>60	1.887(1.624-2.194)	<0.001	1.927(1.622-2.288)	<0.001		1.251(0.981-1.596)	0.071
Gender
Female	1		1			—
Male	1.185(1.023-1.373)	0.024	1.181(1.002-1.392)	0.047		—	—
Decade of diagnosis
1970s	1		1			—
1980s	1.099(0.819-1.476)	0.528	0.855(0.607-1.206)	0.373		—	—
1990s	0.870(0.649-1.168)	0.354	0.642(0.456-0.903)	0.011		—	—
≥2000sa	0.804(0.612-1.057)	0.119	0.526(0.387-0.715)	<0.001		—	—
Location
Appendicular	1		1			1
Axial	1.708(1.418-2.057)	<0.001	1.748(1.427-2.143)	<0.001		1.280(0.979-1.673)	0.071
Other locations	1.066(0.879-1.292)	0.517	1.100(0.887-1.365)	0.385		1.209(0.920-1.589)	0.172
Tumor gradeb
Low	1		1			1
High	2.197(1.653-2.919)	<0.001	2.682(1.906-3.775)	<0.001		1.871(1.141-3.070)	0.013
Tumor stage
Localized	1		1			1
Regional	1.174(0.967-1.425)	0.106	1.252(0.997-1.573)	0.053		1.176(0.893-1.548)	0.250
Distant	2.904(2.322-3.631)	<0.001	3.195(2.479-4.119)	<0.001		2.678(1.936-3.704)	<0.001
Tumor size
<5cm	1		1			1
5-10cm	1.268(0.965-1.666)	0.089	1.280(0.939-1.744)	0.118		1.179(0.804-1.729)	0.399
>10cm	1.699(1.264-2.283)	<0.001	1.727(1.242-2.402)	0.001		1.778(1.161-2.724)	0.008
Surgery
Yes	1		1			1
No	1.604(1.333-1.931)	<0.001	1.460(1.194-1.785)	<0.001		1.405(1.080-1.829)	0.011
Radiation treatment
Yes	1		1			1
No	0.716(0.601-0.852)	<0.001	1.247(1.025-1.518)	0.027		0.898(0.697-1.157)	0.405
Chemotherapy
Yes	—		—			1
No	—	—	—	—		1.337(1.066-1.678)	0.012