Table 3. Cox proportional hazard model analysis (in the training cohort).

Covariates	CSS						OS
	Univariate analysis			Multivariate analysis			Univariate analysis			Multivariate analysis
	HR (95% CI)	P		HR (95% CI)	P		HR (95% CI)	P		HR 95%CI	P
Age								<0.0001			<0.0001
≤65	1	<0.0001		1	<0.0001		1			1
>65	1.284 (1.265–1.303)			1.648 (1.623–1.673)			2.063 (2.038–2.088)			2.386 (2.355–2.416)
TNM stage		<0.0001			<0.0001			<0.0001			<0.0001
0	1			1			1			1
I	1.675 (1.433–1.959)			1.650 (1.349–2.019)			1.285 (1.205–1.371)			1.218 (1.122–1.323)
II	4.724 (4.050–5.510)			4.537 (3.715–5.541)			1.946 (1.826–2.073)			1.805 (1.664–1.959)
III	10.244 (8.786– 11.944)			9.265 (7.588–11.312)			2.616 (2.456–2.788)			2.419 (2.230–2.625)
IV	42.978 (36.860– 50.110)			39.868 (32.653–48.677)			8.851 (8.304–9.433)			8.827 (8.133–9.580)
Tumor grade		<0.0001			<0.0001			<0.0001			<0.0001
I	1			1			1			1
II	1.658 (1.604–1.714)			1.206 (1.166–1.246)			1.318 (1.290–1.348)			1.113 (1.088–1.138)
III	3.159 (3.051–3.270)			1.719 (1.660–1.780)			2.056 (2.007–2.106)			1.457 (1.422–1.493)
IV	3.733 (3.544– 3.932)			1.984 (1.883–2.091)			2.418 (2.319–2.520)			1.692 (1.622–1.764)
Sex		0.748			<0.0001			0.101			<0.0001
Female	1			1			1			1
Male	1.002 (.988–1.017)			1.029 (1.014–1.045)			1.009 (0.998–1.021)			1.072 (1.060–1.085)
NLNs					<0.0001			<0.0001			<0.0001
Low NLN	1	<0.0001		1						1
High NLN‡	0.485 (0.478–0.492)			0.610 (0. 601–0.620)			0.597 (0.590–0.604)			0.682 (0.674–0.690)

CSS, cancer specific survival; OS, overall survival; HR, hazard ratio; CI, confidence interval; TNM, tumor, node, metastases; NLNs, negative lymph nodes. ^†, low NLN for CSS: 0–4 NLNs, and for OS:≥5 NLNs; ^‡, high NLN for OS: 0–7 NLNs, and for OS: ≥8 NLNs.