Table 3. Univariate and multivariate analyses of prognostic factors for disease-free survival.

Variables	Univariate analysis			Multivariate analysis
	HR	95%CI	P value	HR	95%CI	P value
Gender	0.893	0.568-1.403	0.623	1.684	0.425-1.102	0.119
Age	0.876	0.549-1.397	0.577	1.026	0.628-1.675	0.920
Tumor location	1.066	0.846-1.343	0.590	0.997	0.786-1.266	0.983
PTN expression	2.018	1.297-3.142	0.002	1.600	1.002-2.555	0.049
Necrosis rate	3.121	1.917-5.082	<0.001	2.155	1.253-3.707	0.006
TNM stage	3.361	2.100-5.379	<0.001	2.699	1.636-4.452	<0.001

PTN: pleiotrophin; HR: hazard ratio; CI: confidence interval.