Table 2 Univariate and multivariate analyses of the prognostic factors for overall survival in the post-matching cohort

Age, year

0.444

 < 60

1

 ≥ 60

1.142(0.813,1.603)

Gender

0.744

 Female

1

 Male

0.940(0.651,1.359)

BMI

0.972(0.926,1.020)

0.253

Preoperative intestinal obstruction

0.674

 No

1

 Yes

1.092(0.724,1.649)

Preoperative Chemotherapy

0.715

 No

1

 Yes

0.915(0.568,1.475)

Postpostoperative Chemotherapy

0.0467

0.038

 No

1

1

 Yes

0.703(0.497,0.995)

0.670(0.461,0.974)

Surgical approach

0.483

 Laparoscopy

1

 Open

1.131(0.802,1.595)

Resection of liver metastases

0.927

 No

1

 Yes

0.980(0.642,1.496)

Number of hepatic metastases

 1

1

1

 2

1.470(0.971,2.225)

0.069

1.338(0.864,2.070)

0.192

 ≥ 3

1.854(1.091,3.150)

0.022

1.785(1.020,3.123)

0.042

ASA

 1

1

 2

1.632(0.714,3.728)

0.245

 ≥ 3

1.791(0.729,4.401)

0.204

Tumor location

 Left colon

1

 Right colon

1.227(0.798,1.887)

0.352

 Rectum

0.746(0.467,1.170)

0.202

Tumor size, cm

 < 2

1

 2—5

1.273(0.469,3.454)

0.636

 > 5

1.166(0.394,3.452)

0.782

Differentiation

 Well

1

 Moderately

0.601(0.302,1.198)

0.148

 Poorly

1.447(0.703,2.980)

0.315

T stage

0.250

 T1/T2

1

 T3/T4

1.796(0.662,4.876)

N stage

 N0

1

1

 N1

0.972(0.6002,1.575)

0.909

1.096(0.645,1.862)

0.735

 N2

1.696(1.034,2.781)

0.036

1.861(0.898,3.858)

0.095

No of sampled LNs

0.987(0.9654,1.010)

0.257

No of positive LNs

1.062(1.005,1.122)

0.032

0.994(0.912,1.083)

0.886

Lymphovascular invasion

0.032

0.048

 LVI(-)

1

1

 LVI(+)

1.450(1.031,2.040)

1.424(1.004,2.022)

Peri/intraneural invasion

0.108

 PNI(-)

1

 PNI(+)

0.752(0.530,1.065)

Tumor deposits

0.328

 Absent

1

 Present

1.458(0.882,2.032)

CEA level

0.929

 Normal

1

 Elevated

0.984(0.692,1.397)

CA12−5 level

< 0.001

0.002

 Normal

1

1

 Elevated

2.167(1.395,3.367)

2.019(1.276,3.197)

CA19−9 level

< 0.001

0.012

 Normal

1

1

 Elevated

2.483(1.656,3.723)

1.862(1.149,3.018)