Table 2. Univariate and multivariate analysis of overall survival in training set.

Characteristics	Univariate analysis			Multivariate analysis			C-index	AIC
	β	HR (95% CI)	P value	β	HR (95% CI)	P value
Age	0.203	1.225 (1.026–1.464)	0.025	0.283	1.327 (1.053–1.671)	0.016	0.528	3936.8
Gender	0.017	1.017 (0.818–1.265)	0.879				0.499	3935.5
Tumor location	0.003	1.003 (1.001–1.006)	0.004				0.516	3937.0
Macroscopic type	0.540	1.716 (1.566–1.879)	< 0.001	0.257	1.292 (1.109–1.507)	0.001	0.653	3832.8
Differentiation degree	0.422	1.525 (1.352–1.720)	< 0.001				0.593	3894.7
Tumor diameter	0.632	1.882 (1.721–2.058)	< 0.001				0.686	3835.3
T stage	0.736	2.087 (1.889–2.306)	<0.001				0.681	3780.3
N stage	0.657	1.930 (1.798–2.072)	< 0.001	0.561	1.753 (1.576–1.949)	< 0.001	0.736	3698.2
V stage	0.681	1.975 (1.820–2.144)	< 0.001	0.340	1.405 (1.235–1.599)	< 0.001	0.715	3768.2
Vessel invasion	1.087	2.966 (2.282–3.855)	< 0.001				0.614	3871.8
Neural invasion	1.237	3.445 (2.395–4.955)	< 0.001				0.579	3880.2

HR: Hazard ratio; CI: Confidence interval.