Table 2 Univariate and multivariate analysis of overall survival in the training cohort

Sex

 Male

Reference

 Female

0.786(0.752–0.822)

< 0.001

Age

  < =76

Reference

 77–86

1.725(1.643–1.811)

< 0.001

  > =87

2.868(2.699–3.047)

< 0.001

Marital status

 Unmarried

Reference

 Married

0.762(0.727–0.798)

< 0.001

 Unknown

0.957(0.873–1.050)

0.351

Tumor site

 Colon

Reference

 Rectum

0.991(0.936–1.050)

0.765

Grade

 I

Reference

 II

1.114(1.022–1.215)

0.014

 III

1.315(1.195–1.447)

< 0.001

 IV

1.413(1.247–1.601)

< 0.001

 Unknown

1.146(1.005–1.307)

0.042

SEER_stage

 Localized

Reference

 Regional

1.047(0.973–1.126)

0.222

 Distant

1.181(0.975–1.431)

0.088

AJCC_stage

 I

–

–

 II

–

–

 III

–

–

 IV

–

–

AJCC_T

 T1

Reference

 T2

1.083(0.979–1.199)

0.123

 T3

1.353(1.233–1.486)

< 0.001

 T4

2.173(1.953–2.418)

< 0.001

AJCC_N

 N0

Reference

 N1

1.365(1.282–1.453)

< 0.001

 N2

1.975(1.845–2.113)

< 0.001

AJCC_M

 M0

Reference

 M1

2.017(1.662–2.448)

< 0.001

Bone metastasis

 No

Reference

 Yes

1.393(1.058–1.835)

0.018

 Unknown

1.507(0.909–2.500)

0.112

Brain metastasis

 No

Reference

 Yes

2.145(1.401–3.285)

< 0.001

 Unknown

0.687(0.415–1.135)

0.142

Liver metastasis

 No

Reference

 Yes

1.329(1.209–1.462)

< 0.001

 Unknown

0.962(0.684–1.352)

0.822

Lung metastasis

 No

Reference

 Yes

1.327(1.178–1.495)

< 0.001

 Unknown

1.432(1.033–1.984)

0.031

Tumor size

  < =3.4

Reference

 3.5–5.9

1.026(0.968–1.088)

0.379

  > =6

1.137(1.069–1.210)

< 0.001

 Unknown

1.272(1.156–1.398)

< 0.001