Table 2.

Univariate and multivariate Cox regression analyses predicting overall survival (OS) for training cohort

Characteristic	Univariate		Multivariate
	HR (95% CI)	P	HR (95% CI)	P
Age (years)
<50	1		1
50–74	1.30 (1.22–1.38)	<0.001	1.18 (1.11–1.26)	<0.001
≥75	2.60 (2.42–2.80)	<0.001	1.84 (1.71–1.99)	<0.001
Sex
Female	1
Male	0.99 (0.94–1.03)	0.54
Race
Black	1
White	0.92 (0.87–0.98)	0.01	0.89 (0.84–0.94)	<0.001
Others	0.86 (0.78–0.94)	<0.001	0.82 (0.75–0.90)	<0.001
Tumor location
Right colon	1		1
Left colon	0.64 (0.61–0.68)	<0.001	0.76 (0.72–0.80)	<0.001
Rectum	0.66 (0.62–0.70)	<0.001	0.84 (0.78–0.90)	<0.001
Tumor size (mm)
<50	1		1
50–69	1.19 (1.13–1.25)	<0.001	1.13 (1.07–1.19)	<0.001
≥70	1.38 (1.31–1.45)	<0.001	1.24 (1.18–1.31)	<0.001
T stage
T1	1		1
T2	0.52 (0.44–0.61)	<0.001	0.58 (0.49–0.69)	<0.001
T3	0.66 (0.60–0.72)	<0.001	0.74 (0.67–0.82)	<0.001
T4	0.97 (0.88–1.07)	0.58	1.00 (0.90–1.11)	0.97
N stage
N0	1		1
N1	1.01 (0.95–1.08)	0.64	1.13 (1.06–1.21)	<0.001
N2	1.36 (1.29–1.45)	<0.001	1.55 (1.46–1.66)	<0.001
Histological differentiation
Highly	1		1
Moderate	1.03 (0.93–1.15)	0.55	1.19 (1.06–1.32)	<0.001
Poorly	1.79 (1.60–2.01)	<0.001	1.90 (1.70–2.13)	<0.001
Undifferentiated	1.92 (1.68–2.19)	<0.001	1.99 (1.74–2.28)	<0.001
Number of LN examination
<12	11		1
≥12	0.69 (0.66–0.72)	<0.001	0.61 (0.58–0.65)	<0.001
Organ metastasis
0	11		1
1	0.96 (0.91–1.01)	0.12	1.30 (1.23–1.37)	<0.001
>1	1.68 (1.56–1.80)	<0.001	2.20 (2.05–2.38)	<0.001
Radiotherapy
No	1		1
Yes	0.57 (0.52–0.62)	<0.001	0.79 (0.72–0.87)	<0.001
Chemotherapy
No	1		1
Yes	0.35 (0.33–0.36)	<0.001	0.37 (0.35–0.39)	<0.001

HR, hazard ratio; CI, confidence interval.