Table 2. Univariate and multivariate Cox regression of prognostic factors for overall survival in OS patients.

Parameter	Univariate analysis			Multivariate analysis
	HR	95% CI	P	HR	95% CI	P
Age (years) (≤18 compared with >18)	0.869	0.559–1.350	0.531
Gender (Female compared with male)	1.365	0.845–2.205	0.204
Enneking stage (I-II A compared with II B-III)	4.661	2.686–8.091	<0.001	3.610	1.627–8.010	0.002
Tumor size (≤8 compared with >8 cm or discontinuous tumors)	3.171	1.954–5.148	<0.001	1.060	0.538–2.088	0.866
Histological grade (G1–G2 compared with G3–G4)	1.288	0.822–2.018	0.270
BDNF-AS expression (Low compared with high)	0.375	0.238–0.591	<0.001	0.524	0.327–0.838	0.007

Abbreviations: HR, hazard ratio; 95% CI, 95% confidence interval.