Table 3 Univariate and multivariate analyses of the prognostic factors for overall survival in the post-matching cohort

≤ 60

Ref.

-

Ref.

-

> 60

1.663 (1.215–2.276)

0.001

1.357 (0.953–1.932)

0.091

BMI

0.953 (0.903–1.005)

0.075

Tumor size (cm)

≤ 2.70

Ref.

-

2.70–4.40

0.862 (0.519–1.432)

0.567

> 4.40

1.171 (0.716–1.914)

0.529

Obstruction before surgery

Absent

Ref.

-

Ref.

-

present

2.312 (1.62–3.299)

< 0.001

2.101 (1.393–3.168)

< 0.001

Sex

Male

Ref.

-

Female

0.965 (0.701–1.329)

0.826

Family history of cancer

No

Ref.

-

Yes

0.793 (0.458–1.374)

0.408

Post radiotherapy

No

Ref.

-

Yes

0.724 (0.339–1.546)

0.405

Adjuvant chemotherapy

No

Ref.

-

Ref.

-

Yes

0.537 (0.391–0.737)

< 0.001

0.497 (0.351–0.704)

< 0.001

Vascular cancer embolus

Absent

Ref.

-

Ref.

-

Present

1.43 (1.032–1.982)

0.032

1.129 (0.791–1.611)

0.504

Perineural invasion

Absent

Ref.

-

Ref.

-

Present

1.445 (1.051–1.986)

0.024

1.881 (1.35–2.62)

< 0.001

Histological grade

Poorly

Ref.

-

Ref.

-

Moderately

0.568 (0.391–0.825)

0.003

0.69 (0.461–1.033)

0.071

Well

0.703 (0.397–1.246)

0.228

1.034 (0.569–1.879)

0.914

Stage

I

Ref.

-

II

1.6 (0.215–11.92)

0.647

III

5.06 (0.705–36.295)

0.107

IV

7.861 (1.08-57.202)

0.042

T stage

T1

Ref.

-

T2

0.152 (0.021–1.081)

0.060

T3

0.598 (0.147–2.429)

0.472

T4

0.884 (0.216–3.618)

0.864

 N stage

N0

Ref.

-

Ref.

-

N1

2.08 (1.384–3.126)

< 0.001

1.841 (1.222–2.775)

0.004

N2

2.661 (1.76–4.024)

< 0.001

2.311 (1.505–3.55)

< 0.001

M stage

M0

Ref.

-

Ref.

-

M1

1.95 (1.333–2.852)

0.001

3.005 (1.96–4.608)

< 0.001

Primary tumor location

Rectum

Ref.

-

Right colon

1.236 (0.839–1.82)

0.284

Left colon

1.273 (0.875–1.853)

0.207

ASA

1

Ref.

-

2

0.502 (0.159–1.584)

0.240

3

0.642 (0.197–2.091)

0.462

4

0.763 (0.217–2.679)

0.673

Previous history of abdominal surgery

No

Ref.

-

Yes

1.227 (0.839–1.793)

0.292

Neoadjuvant chemotherapy

No

Ref.

-

Yes

1.302 (0.663–2.554)

0.443

Preoperative comorbidities

Total patients

No

Ref.

-

Ref.

-

Yes

1.424 (1.024–1.98)

0.035

1.319 (0.924–1.881)

0.127

Cardiovascular disease

No

Ref.

-

Yes

1.371 (0.97–1.938)

0.074

Cerebrovascular disease

No

Ref.

-

Yes

1.447 (0.639–3.273)

0.375

COPD

No

Ref.

-

Yes

1.227 (0.454–3.312)

0.687

Diabetes

No

Ref.

-

Yes

1.362 (0.772–2.403)

0.286

CEA (ng/mL)

< 5

Ref.

-

Ref.

-

≥ 5

2.439 (1.759–3.384)

< 0.001

1.838 (1.291–2.617)

0.001

CA199 (kU/L)

< 37

Ref.

-

Ref.

-

≥ 37

2.128 (1.537–2.948)

< 0.001

1.597 (1.123–2.27)

0.009

CA125 (U/mL)

< 35

Ref.

-

Ref.

-

≥ 35

2.223 (1.485–3.33)

< 0.001

1.466 (0.932–2.305)

0.098