Table 5.

Multivariable Cox regression model in the training, internal validation, and external validation cohorts of CSS.

Variables		Training dataset			Internal validation cohort			External validation cohort
		HR	95% CI	P	HR	95% CI	P	HR	95% CI	P
Age	<60	1			1			1
	≥60	1.253	(1.160, 1.355)	<0.0001	1.221	(1.111, 1.341)	<0.0001	1.606	(1.194, 2.160)	0.0017
Tumor location	Colon	1			1			1
	Rectum	0.91	(0.845, 0.980)	0.013	1.102	(1.007, 1.206)	0.0339	1.274	(0.960, 1.693)	0.094
Differentiation	Well	1			1			1
	Moderately	0.807	(0.728, 0.894)	<0.0001	0.712	(0.626, 0.809)	<0.0001	0.416	(0.275, 0.630)	<0.0001
	Poorly	1			1			1
	Undifferentiated; anaplastic	1.187	(0.976, 1.445)	0.0867	0.974	(0.741, 1.280)	0.8487	1.549	(0.628, 3.820)	0.3421
	Unknown	1.707	(1.388, 2.099)	<0.0001	1.387	(1.045, 1.840)	0.0235	2.453	(0.955, 6.297)	0.0622
Histological type	Adenocarcinoma, NOS	2.173	(1.706, 2.767)	<0.0001	1.508	(1.088, 2.090)	0.0135	9.22	(2.876, 29.555)	0.0002
	Mucinous adenocarcinoma	1.073	(0.782, 1.473)	0.6605	1.106	(0.745, 1.642)	0.6176	1.006	(0.265, 3.818)	0.9928
	Signet ring cell carcinoma	1			1			1
	Other	1.167	(1.084, 1.257)	<0.0001	1.08	(0.986, 1.183)	0.0961	1.286	(0.958, 1.727)	0.0941
Size, mm	<55	1			1			1
	≥55	1.628	(1.506, 1.759)	<0.0001	1.546	(1.404, 1.703)	<0.0001	1.663	(1.226, 2.254)	0.0011
TNM	IVA	1.07	(0.830, 1.379)	0.6022	1.096	(0.810, 1.483)	0.5516	2.356	(1.116, 4.973)	0.0246
	IVB	1			1			1
	IVNOS	2.953	(2.720, 3.205)	<0.0001	2.99	(2.708, 3.300)	<0.0001	2.573	(1.870, 3.540)	<0.0001
No. of sampled LNs		0.977	(0.972, 0.981)	<0.0001	0.979	(0.973, 0.985)	<0.0001	0.961	(0.941, 0.982)	0.0003
No. of positive LNs		1.051	(1.044, 1.058)	<0.0001	1.049	(1.041, 1.058)	<0.0001	1.02	(0.994, 1.047)	0.1298
Metastatic surgery	Yes	1			1			1
	No	1.38	(1.266, 1.504)	<0.0001	1.312	(1.179, 1.461)	<0.0001	1.377	(0.930, 2.039)	0.1103