Table 4 Univariate and multivariate analyses of the prognostic factors for disease-free survival in the post-matching cohort

Age (years)

≤ 60

Ref.

-

> 60

1.128 (0.851–1.494)

0.402

BMI

0.99 (0.944–1.039)

0.691

Tumor size (cm)

≤ 2.70

Ref.

-

2.70–4.40

0.954 (0.623–1.459)

0.827

> 4.40

0.854 (0.556–1.312)

0.473

Obstruction before surgery

Absent

Ref.

-

Ref.

-

present

1.494 (1.05–2.124)

0.025

1.734 (1.17–2.568)

0.006

Sex

Male

Ref.

-

Female

0.832 (0.627–1.104)

0.202

Family history of cancer

No

Ref.

-

Yes

0.989 (0.629–1.555)

0.962

Post radiotherapy

No

Ref.

-

Yes

0.735 (0.377–1.436)

0.368

Adjuvant chemotherapy

No

Ref.

-

Yes

0.825 (0.624–1.091)

0.178

Vascular cancer embolus

Absent

Ref.

-

Ref.

-

Present

1.584 (1.189–2.109)

0.002

1.244 (0.913–1.696)

0.167

Perineural invasion

Absent

Ref.

-

Ref.

-

Present

1.506 (1.134–2.001)

0.005

1.809 (1.353–2.419)

< 0.001

Histological grade

Poorly

Ref.

-

Ref.

-

Moderately

0.601 (0.429–0.84)

0.003

0.689 (0.482–0.985)

0.041

Well

0.66 (0.391–1.116)

0.121

0.749 (0.44–1.275)

0.287

Stage

I

Ref.

-

II

2.481 (0.339–18.173)

0.371

III

5.86 (0.818–41.989)

0.078

IV

14.046 (1.945-101.454)

0.009

T stage

T1

Ref.

-

T2

0.247 (0.041–1.477)

0.125

T3

0.889 (0.22–3.596)

0.869

T4

1.145 (0.281–4.667)

0.850

 N stage

N0

Ref.

-

Ref.

-

N1

1.434 (1.005–2.048)

0.047

1.314 (0.918–1.879)

0.135

N2

2.397 (1.698–3.383)

< 0.001

1.976 (1.373–2.844)

< 0.001

M stage

M0

Ref.

-

Ref.

-

M1

2.953 (2.145–4.066)

< 0.001

3.27 (2.319–4.611)

< 0.001

Primary tumor location

Rectum

Ref.

-

Right colon

0.9 (0.627–1.292)

0.567

Left colon

1.109 (0.796–1.544)

0.540

ASA

1

Ref.

-

2

0.61 (0.194–1.918)

0.397

3

0.74 (0.229–2.389)

0.614

4

0.825 (0.239–2.85)

0.760

Previous history of abdominal surgery

No

Ref.

-

Yes

0.842 (0.579–1.223)

0.366

Neoadjuvant chemotherapy

No

Ref.

-

Yes

1.159 (0.613–2.192)

0.649

Preoperative comorbidities

Total patients

No

Ref.

-

Yes

1.238 (0.918–1.67)

0.161

Cardiovascular disease

No

Ref.

-

Yes

1.227 (0.896–1.681)

0.203

Cerebrovascular disease

No

Ref.

-

Yes

0.898 (0.37–2.184)

0.813

COPD

No

Ref.

-

Yes

1.2 (0.493–2.916)

0.688

Diabetes

No

Ref.

-

Yes

1.229 (0.726–2.082)

0.442

CEA (ng/mL)

< 5

Ref.

-

Ref.

-

≥ 5

1.839 (1.387–2.439)

< 0.001

1.52 (1.12–2.063)

0.007

CA199 (kU/L)

< 37

Ref.

-

Ref.

-

≥ 37

1.517 (1.116–2.061)

0.008

1.147 (0.825–1.596)

0.414

CA125 (U/mL)

< 35

Ref.

-

Ref.

-

≥ 35

1.558 (1.044–2.326)

0.030

1.193 (0.776–1.834)

0.420