Table 2.

Univariate and multivariate survival analysis of prognostic factors in osteosarcoma.

Variable	Univariate analysis			Multivariate analysis
	Hazard Ratio	95% CI	P value	Hazard Ratio	95% CI	P value
All patients
Age, year	0.996	0.979–1.014	0.680
≤18
>18
Gender	0.932	0.520–1.663	0.811
Male
Female
Tumor site	1.008	0.353–2.715	0.422
Femur
Tibia
Humeral bone
Other
Metastasis	7.819	4.068–15.030	<0.001a	4.893	2.036-13.162	<0.001a
Present
Absent
Recurrence	1.496	0.822–2.720	0.187
Present
Absent
CDK9 expression	3.411	1.924–6.045	<0.001a	3.568	1.512-8.417	0.004a
High
Low
Response to pre-operative chemotherapy	0.240	0.115–0.499	0.002a	0.128	0.026-0.651	0.008a
Good
Poor

^aStatistically significant.